Idiopathic Hypogonadotropic Hypogonadism Research Articles

Diagnostic utility of testosterone priming prior to dynamic tests to differentiate constitutional delay in puberty from isolated hypogonadotropic hypogonadism in boys

BackgroundDifferentiation between isolated hypogonadotropic hypogonadism (IHH) and constitutional delay in puberty (CDP) throughout adolescence can be challenging for doctors. This study examines the withdrawal effects of short-term, low-dose testosterone treatment (testosterone priming) on the ability of dynamic testing to distinguish between CDP and IHH based on activation of the hypothalamo-pituitary–testicular axis.MethodsA case–control study included 20 boys with delayed puberty (group A) and 20 patients with IHH (group B). Both groups underwent Triptorelin and human chorionic gonadotropin (hCG) stimulation tests before and 2 months after testosterone injections (100 mg) intramuscularly every 4 weekly for 3 months.ResultsThe triptorelin-stimulated 4-h LH with a cutoff of 2.4 IU/L and the hCG-stimulated testosterone with a cutoff of 1.160 ng/mL had sensitivities of 65% each, and specificities of 90% and 95%, respectively, to diagnose CDP. After testosterone withdrawal, the cut-off values for 4-h LH were 8.850 IU/L and 3.190 ng/mL for hCG-stimulated testosterone. Basal inhibin B > 88.25 pg/ml was found to be a differentiating factor in diagnosing CDP after testosterone withdrawal.Conclusionsfollowing the withdrawal of testosterone therapy, Inhibin B levels or 4-h stimulated LH are the most effective discriminant assays to distinguish CDP from IHH.

Efficacy of Gonadotropin Treatment for Induction of Spermatogenesis in Men With Pathologic Gonadotropin Deficiency: A Meta-Analysis.

Hypogonadotropic hypogonadism (HH) is a treatable cause of nonobstructive azoospermic male infertility. Gonadotropin treatment can successfully induce spermatogenesis in most patients, although comprehensive quantitative summary data on spermatogenic outcomes like those required to induce pregnancy is lacking in the literature. Systematic review and meta-analysis of outcomes related to male reproductive function following gonadotropin treatment. Our search strategy identified 41 studies encompassing 1673 patients with a mean age of 25 (± 5) years. Average sperm concentration achieved after a median of 18 months of gonadotropin treatment was 11.6 M/mL of ejaculate (95% CI 8.4-14.9). Sperm concentrations > 0, > 1, > 5, > 10 and > 20 M/mL were achieved by 78%, 55%, 36%, 24% and 15% of patients, respectively. Mean sperm output and the proportion of patients achieving all sperm thresholds were significantly greater following combined hCG/FSH treatment compared with hCG monotherapy. When compared by diagnosis, patients with congenital HH (CHH) had significantly lower mean sperm output compared with patients with hypopituitarism or mixed patient cohorts that did not differentiate between CHH and hypopituitarism. Treatment-related increases in testosterone and testicular volume (TV) were not different between hCG and combined hCG/FSH treated patients, although increases in TV were lower in men with CHH compared with those with hypopituitarism. Gonadotropin treatment successfully induced spermatogenesis in most men with pathological gonadotropin deficiency. Sperm outputs more consistent with those typically needed to induce a natural pregnancy were less commonly achieved. Despite similar effects on serum testosterone and TV, combined hCG/FSH appeared more efficacious than hCG alone at inducing spermatogenesis.

Hypogonadotropic hypogonadism as a cause of NOA and its treatment.

Hypogonadotropic hypogonadism (HH) represents a relatively rare cause of nonobstructive azoospermia (NOA), but its knowledge is crucial for the clinical andrologists, as it represents a condition that can be corrected with medical therapy in 3 quarters of cases. There are forms of congenital HH, whether or not associated with an absent sense of smell (anosmic HH or Kallmann syndrome, and normosmic HH, respectively), and forms of acquired HH. In congenital HH, complete absence of pubertal development is characteristic. On the other hand, if the deficit occurs after the time of pubertal development, as in acquired HH patients, infertility and typical symptoms of late-onset hypogonadism are the main reasons for seeking medical assistance. Gonadotropin-releasing hormone (GnRH) or gonadotropin replacement therapy is the mainstay of drug therapy and offers excellent results, although a small but significant proportion of patients do not achieve sufficient responses.

Spontaneous Puberty in a Male with Heterozygous PROK2 Gene Mutation Presenting with Micropenis and Synkinesis

Male idiopathic hypogonadotropic hypogonadism is characterized by absent or partial sexual maturation. The Prok2/ProkR2 genes are among the genes implicated in this condition. Objective: Reporting a case harbouring a missense mutation in the PROK2 gene, presenting, at 7 1/2 years with micropenis and synkinesis. History and Examination: Born at full term, with no pre/post-natal complications. On presentation his penile stretched length was 3.8 cm, (-2.5 SDS). Both testes were descended, with a testicular volume of 2ml. Results: On follow up, the testicular volume of 4ml bilaterally, was detected at 11 1/2 years, after 3 testosterone monthly injections. The penile length increased to 5.2 cm. Puberty continued to progress spontaneously. Genetic Analysis revealed a heterozygous missense mutation in PROK2 gene, exon 4, chromosome 3. Conclusion: Heterozygous mutations in the PROK2 gene can present with reproductive and non-reproductive manifestations. They may progress spontaneously into puberty, in the absence of micro/cryptorchidism.

9242 SOX11 mutations cause hypogonadotropic hypogonadism through both hypothalamic and pituitary level deficits

Abstract Disclosure: B. Sun: None. S. Stockman: None. M. Stamou: None. L. Plummer: None. K. Salnikov: None. D. Kotan: None. K. Topaloglu: None. S.B. Seminara: None. R. Balasubramanian: None. AbstractPurpose: Human SOX11 mutations cause Coffin-Siris Syndrome (CSS) which is clinically characterized by aplasia or hypoplasia of the distal phalanx/nail of the fifth digit, developmental delay, cognitive impairment, and distinctive facial features. Recent studies show hypogonadotropic hypogonadism (HH) occurs in ∼20% of patients with SOX11 mutations. The genotypic-phenotypic spectrum of SOX11 mutations in patients presenting with Idiopathic Hypogonadotropic Hypogonadism (IHH) is unknown. Methods: Exome sequencing data from 1810 unrelated IHH probands (anosmic and normosmic forms) were reviewed for SOX11 rare sequence variants (RSVs) [minor allele frequency <0.1%]. Rare variant association analysis (RVAS) and domain-based enrichment for SOX11 RSVs was performed between the IHH and gnomAD population cohort. RSVs predicted as pathogenic/likely pathogenic by ACMG criteria were deemed as pathogenic RSVs and detailed phenotypic analysis was undertaken for these variants. Results: A total of 4 pathogenic SOX11 RSVs were identified in 5 IHH cases. RVAS analysis showed that SOX11 inactivating RSVs (frameshift/non-sense) across the entire protein was enriched in the IHH cohort (2 RSVs in 3 IHH cases (p.S303X [de-novo]; p p.S345Afs*13); p<0.0001) while SOX11 missense RSVs was enriched only within the SOX11-HMG domain (2 RSVs in 2 IHH cases (p.G84D [de-novo]; p.P114S; p=0.003). Phenotypic review of individuals with pathogenic SOX11-RSVs revealed a spectrum of endocrine defects including: anosmic and normosmic forms of IHH, growth-hormone (GH) deficiency, neuroimaging defects (pituitary microadenoma and hypothalamic mass), and hypothyroidism. Additionally, we also identified a pathogenic SOX11 HMG domain RSV in a patient with functional HH (p.R100Q). CSS-associated features were present in almost all individuals with pathogenic SOX11 RSVs. Conclusions: This study validates SOX11 mutations as causal for IHH and reiterates the critical importance of the SOX11-HMG domain in disease pathogenesis. The spectrum of endocrine abnormalities in SOX11-related human disorders includes IHH, functional HH, GH deficiency, pituitary lesions, and hypothyroidism. The association of congenital anosmic and normosmic forms of IHH, functional HH, and anatomic abnormalities of the pituitary gland suggest that the pathogenesis of HH in SOX11-disorder may stem from both hypothalamic and pituitary level deficits. Presentation: 6/1/2024

8474 SOX11 mutations cause hypogonadotropic hypogonadism through both hypothalamic and pituitary level deficits

Abstract Disclosure: B. Sun: None. S. Stockman: None. M. Stamou: None. L. Plummer: None. K. Salnikov: None. D. Kotan: None. K. Topaloglu: None. S.B. Seminara: None. R. Balasubramanian: None. AbstractPurpose: Human SOX11 mutations cause Coffin-Siris Syndrome (CSS) which is clinically characterized by aplasia or hypoplasia of the distal phalanx/nail of the fifth digit, developmental delay, cognitive impairment, and distinctive facial features. Recent studies show hypogonadotropic hypogonadism (HH) occurs in ∼20% of patients with SOX11 mutations. The genotypic-phenotypic spectrum of SOX11 mutations in patients presenting with Idiopathic Hypogonadotropic Hypogonadism (IHH) is unknown. Methods: Exome sequencing data from 1810 unrelated IHH probands (anosmic and normosmic forms) were reviewed for SOX11 rare sequence variants (RSVs) [minor allele frequency <0.1%]. Rare variant association analysis (RVAS) and domain-based enrichment for SOX11 RSVs was performed between the IHH and gnomAD population cohort. RSVs predicted as pathogenic/likely pathogenic by ACMG criteria were deemed as pathogenic RSVs and detailed phenotypic analysis was undertaken for these variants. Results: A total of 4 pathogenic SOX11 RSVs were identified in 5 IHH cases. RVAS analysis showed that SOX11 inactivating RSVs (frameshift/non-sense) across the entire protein was enriched in the IHH cohort (2 RSVs in 3 IHH cases (p.S303X [de-novo]; p p.S345Afs*13); p<0.0001) while SOX11 missense RSVs was enriched only within the SOX11-HMG domain (2 RSVs in 2 IHH cases (p.G84D [de-novo]; p.P114S; p=0.003). Phenotypic review of individuals with pathogenic SOX11-RSVs revealed a spectrum of endocrine defects including: anosmic and normosmic forms of IHH, growth-hormone (GH) deficiency, neuroimaging defects (pituitary microadenoma and hypothalamic mass), and hypothyroidism. Additionally, we also identified a pathogenic SOX11 HMG domain RSV in a patient with functional HH (p.R100Q). CSS-associated features were present in almost all individuals with pathogenic SOX11 RSVs. Conclusions: This study validates SOX11 mutations as causal for IHH and reiterates the critical importance of the SOX11-HMG domain in disease pathogenesis. The spectrum of endocrine abnormalities in SOX11-related human disorders includes IHH, functional HH, GH deficiency, pituitary lesions, and hypothyroidism. The association of congenital anosmic and normosmic forms of IHH, functional HH, and anatomic abnormalities of the pituitary gland suggest that the pathogenesis of HH in SOX11-disorder may stem from both hypothalamic and pituitary level deficits. Presentation: 6/1/2024

12413 Reversal Of Congenital Hypogonadotropic Hypogonadism (CHH) In A Woman With A Heterozygous Inactivating Variant In GnRHR Gene

Abstract Disclosure: S.W. Nyunt: None. M. Phylactou: None. K. Koysombat: None. J. Tsoutsouki: None. A.C. Yeung: None. M. Young: None. A. Newman: None. A.N. Comninos: None. Y. Mamoojee: None. N. Pitteloud: None. R. Quinton: None. W.S. Dhillo: None. A. Abbara: None. Introduction: Congenital Hypogonadotropic Hypogonadism (CHH) is a rare genetic condition with central hypogonadism and pubertal failure affecting both sexes. Reversal of CHH is far less commonly reported in women in the literature. We presented a case of reversal of CHH in a woman with heterozygous GnRHR mutation and the use of kisspeptin in interrogating hypothalamic function. Case history: Our patient presented with primary amenorrhea and incomplete puberty aged 15 yrs. Based on high BMI from early adolescence, clinical hyperandrogenism, family history of polycystic ovary syndrome (PCOS) and insulin resistance, she was diagnosed with PCOS and commenced on a combined oral contraceptive (COC), achieving breast development.Aged 21yrs, she was reassessed for amenorrhea off COC. Biochemical assessment revealed hypogonadotropic hypogonadism (HH): LH 0.2 IU/L, FSH 0.3 IU/L, estradiol <92 pmol/L. She had a normal sense of smell and Tanner 4 breasts; MRI demonstrated normal olfactory bulbs and pituitary. The diagnosis was therefore revised to CHH and COC was restarted, later changed to HRT due to hypertension. A 22-gene CHH panel (R148) identified a heterozygous pathogenic variant c.3171>Gp in GNRHR.At reassessment off HRT aged 32yrs, she remained amenorrheic. Ultrasound showed normal ovarian morphology, antral follicle counts 17 and endometrial thickness 5.8mm; hormonal assays: LH 5.0 IU/L, FSH 8.3 U/L, estradiol 162 pmol/L, AMH 12.2 pmol/L, testosterone 1.6 nmol/L (RR <2.0), SHBG 35 nmol/L (RR 30-100 nmol/L).She then achieved 20kg weight loss (BMI 41.8 to 35.2 kg/m2) on GLP-1 agonist. GnRH test (Gonadorelin 100mcg) incremented LH from 5.16 to 44.46 IU/L and FSH from 6.47 to 15.27 IU/L at 60 mins. After an intravenous kisspeptin (9.6nmol/kg) bolus, LH rose from 5.05 to 29.99 IU/L, FSH from 6.68 to 13.91 IU/L. Off HRT, she began having regular cycles (estradiol 800 pmol/L). Discussion: CHH was diagnosed based on primary amenorrhea, HH and pathogenic GnRHR variant that would not, however, be expected to result in a productive phenotype in the absence of a second deleterious allele (oligogenicity occurs in 20% of CHH), so whole exome sequencing is awaited. Kisspeptin is a potent stimulator of hypothalamic GnRH neurons and can be used to interrogate hypothalamic function. Typically, gonadotrophin responses to kisspeptin are minimal in CHH. Thus, her kisspeptin response was not consistent with CHH at time of assessment, indicating reversal of CHH (seen in 20% of CHH, particularly with GnRHR variants). Notably, her kisspeptin response was higher than in healthy women, consistent with decreased hypothalamic function and potentially a ‘Female Obesity-Related Hypogonadism’. Our case highlights the value of interrogating hypothalamic function using kisspeptin, both for the diagnosis of CHH, and to identify alternate pathology, as well as to identify recovery of reproductive function in CHH reversal. Presentation: 6/1/2024

12413 Reversal Of Congenital Hypogonadotropic Hypogonadism (CHH) In A Woman With A Heterozygous Inactivating Variant In GnRHR Gene

Abstract Disclosure: S.W. Nyunt: None. M. Phylactou: None. K. Koysombat: None. J. Tsoutsouki: None. A.C. Yeung: None. M. Young: None. A. Newman: None. A.N. Comninos: None. Y. Mamoojee: None. N. Pitteloud: None. R. Quinton: None. W.S. Dhillo: None. A. Abbara: None. Introduction: Congenital Hypogonadotropic Hypogonadism (CHH) is a rare genetic condition with central hypogonadism and pubertal failure affecting both sexes. Reversal of CHH is far less commonly reported in women in the literature. We presented a case of reversal of CHH in a woman with heterozygous GnRHR mutation and the use of kisspeptin in interrogating hypothalamic function. Case history: Our patient presented with primary amenorrhea and incomplete puberty aged 15 yrs. Based on high BMI from early adolescence, clinical hyperandrogenism, family history of polycystic ovary syndrome (PCOS) and insulin resistance, she was diagnosed with PCOS and commenced on a combined oral contraceptive (COC), achieving breast development.Aged 21yrs, she was reassessed for amenorrhea off COC. Biochemical assessment revealed hypogonadotropic hypogonadism (HH): LH 0.2 IU/L, FSH 0.3 IU/L, estradiol <92 pmol/L. She had a normal sense of smell and Tanner 4 breasts; MRI demonstrated normal olfactory bulbs and pituitary. The diagnosis was therefore revised to CHH and COC was restarted, later changed to HRT due to hypertension. A 22-gene CHH panel (R148) identified a heterozygous pathogenic variant c.3171>Gp in GNRHR.At reassessment off HRT aged 32yrs, she remained amenorrheic. Ultrasound showed normal ovarian morphology, antral follicle counts 17 and endometrial thickness 5.8mm; hormonal assays: LH 5.0 IU/L, FSH 8.3 U/L, estradiol 162 pmol/L, AMH 12.2 pmol/L, testosterone 1.6 nmol/L (RR <2.0), SHBG 35 nmol/L (RR 30-100 nmol/L).She then achieved 20kg weight loss (BMI 41.8 to 35.2 kg/m2) on GLP-1 agonist. GnRH test (Gonadorelin 100mcg) incremented LH from 5.16 to 44.46 IU/L and FSH from 6.47 to 15.27 IU/L at 60 mins. After an intravenous kisspeptin (9.6nmol/kg) bolus, LH rose from 5.05 to 29.99 IU/L, FSH from 6.68 to 13.91 IU/L. Off HRT, she began having regular cycles (estradiol 800 pmol/L). Discussion: CHH was diagnosed based on primary amenorrhea, HH and pathogenic GnRHR variant that would not, however, be expected to result in a productive phenotype in the absence of a second deleterious allele (oligogenicity occurs in 20% of CHH), so whole exome sequencing is awaited. Kisspeptin is a potent stimulator of hypothalamic GnRH neurons and can be used to interrogate hypothalamic function. Typically, gonadotrophin responses to kisspeptin are minimal in CHH. Thus, her kisspeptin response was not consistent with CHH at time of assessment, indicating reversal of CHH (seen in 20% of CHH, particularly with GnRHR variants). Notably, her kisspeptin response was higher than in healthy women, consistent with decreased hypothalamic function and potentially a ‘Female Obesity-Related Hypogonadism’. Our case highlights the value of interrogating hypothalamic function using kisspeptin, both for the diagnosis of CHH, and to identify alternate pathology, as well as to identify recovery of reproductive function in CHH reversal. Presentation: 6/1/2024

8235 Mutations in EMX2, a Homeodomain Transcription Factor, Cause Idiopathic Hypogonadotropic Hypogonadism

Abstract Disclosure: M. Stamou: None. M. Tompkin: None. H. Bow: None. H. Brand: None. L. Plummer: None. M. Talkowski: None. Y. Shen: None. D. Wu: None. R. Balasubramanian: None. S. Wray: None. S.B. Seminara: None. The genetic etiology of infertility remains largely unknown. To identify novel human infertility genes, we applied a de novo rare variant analysis in 142 parent-proband trios with idiopathic hypogonadotropic hypogonadism (IHH), a Mendelian disease caused by Gonadotropin Releasing Hormone (GnRH) deficiency. The discovery pipeline identified 43 rare de novo copy number variants (CNVs-deletions) spanning 263 genes and 213 rare de novo single nucleotide variants (SNVs) in 191 genes. Four genes were found to be affected by both rare de novo CNVs and SNVs among unrelated sporadic IHH probands. A rare variant association testing for protein truncating variants (PTVs) in the IHH cohort (N=1,394) compared to gnomAD controls (N=125,784) revealed that 3/4 genes demonstrated enrichment for PTVs in the IHH cohort compared to controls: the 2 known for IHH genes (ANOS1 and FGFR1) and one novel candidate gene, EMX2. IHH probands with de novo EMX2 variants demonstrated developmental delay and hearing loss. Common EMX2 variants were linked to delayed puberty/infertility, hearing loss and Parkinson’s disease in a phenome-wide association study of the Massachusetts General Brigham Biobank (N=65,253). Emx2 lineage tracing was conducted on Emx2Cre/+; RosatdT/+ and Emx2Cre/-; RosatdT/+ mouse embryos at embryonic day(E) 13.5. The tdT reporter was co-expressed in neuroendocrine GnRH (nGnRH) cells as they migrated from the olfactory pit to the nasal forebrain junction. WT and KO embryos from Emx2+/- matings were immunostained for GnRH across E12.5, E13.5, E14.5 and E16. The total number of nGnRH cells was greater in the Emx2 KO mice compared to WT littermates. However, by E16.5, fewer nGnRH cells were detected in the forebrain of Emx2 KO, compared to WT (WT= 496±28, KO=384±147, p=0.0125). Thus, failure of nGnRH neurons to enter the forebrain could contribute to the IHH pathogenesis. In conclusion, by utilizing a de novo variant analysis and a mouse model, EMX2 was uncovered as a novel gene for human infertility. Presentation: 6/1/2024

8235 Mutations in EMX2, a Homeodomain Transcription Factor, Cause Idiopathic Hypogonadotropic Hypogonadism

Abstract Disclosure: M. Stamou: None. M. Tompkin: None. H. Bow: None. H. Brand: None. L. Plummer: None. M. Talkowski: None. Y. Shen: None. D. Wu: None. R. Balasubramanian: None. S. Wray: None. S.B. Seminara: None. The genetic etiology of infertility remains largely unknown. To identify novel human infertility genes, we applied a de novo rare variant analysis in 142 parent-proband trios with idiopathic hypogonadotropic hypogonadism (IHH), a Mendelian disease caused by Gonadotropin Releasing Hormone (GnRH) deficiency. The discovery pipeline identified 43 rare de novo copy number variants (CNVs-deletions) spanning 263 genes and 213 rare de novo single nucleotide variants (SNVs) in 191 genes. Four genes were found to be affected by both rare de novo CNVs and SNVs among unrelated sporadic IHH probands. A rare variant association testing for protein truncating variants (PTVs) in the IHH cohort (N=1,394) compared to gnomAD controls (N=125,784) revealed that 3/4 genes demonstrated enrichment for PTVs in the IHH cohort compared to controls: the 2 known for IHH genes (ANOS1 and FGFR1) and one novel candidate gene, EMX2. IHH probands with de novo EMX2 variants demonstrated developmental delay and hearing loss. Common EMX2 variants were linked to delayed puberty/infertility, hearing loss and Parkinson’s disease in a phenome-wide association study of the Massachusetts General Brigham Biobank (N=65,253). Emx2 lineage tracing was conducted on Emx2Cre/+; RosatdT/+ and Emx2Cre/-; RosatdT/+ mouse embryos at embryonic day(E) 13.5. The tdT reporter was co-expressed in neuroendocrine GnRH (nGnRH) cells as they migrated from the olfactory pit to the nasal forebrain junction. WT and KO embryos from Emx2+/- matings were immunostained for GnRH across E12.5, E13.5, E14.5 and E16. The total number of nGnRH cells was greater in the Emx2 KO mice compared to WT littermates. However, by E16.5, fewer nGnRH cells were detected in the forebrain of Emx2 KO, compared to WT (WT= 496±28, KO=384±147, p=0.0125). Thus, failure of nGnRH neurons to enter the forebrain could contribute to the IHH pathogenesis. In conclusion, by utilizing a de novo variant analysis and a mouse model, EMX2 was uncovered as a novel gene for human infertility. Presentation: 6/1/2024

6846 Rare Variants in SEMA3A in Individuals with Constitutional Delay of Puberty (CDP)

Abstract Disclosure: W. He: None. E.C. Schafer: None. R. Brauner: None. A. Delaney: None. L. Dunkel: None. R. Grinspon: None. J.E. Hall: None. J.N. Hirschhorn: None. S. Howard: None. A. Latronico: None. A.A. Jorge: None. K. McElreavey: None. V. Mericq: None. P.M. Merino: None. M.R. Palmert: None. R.A. Rey: None. R.C. Rezende: None. S.B. Seminara: None. N. Shaw: None. T. Delayed Puberty Genetics Consortium: None. Y. Chan: None. Background: Constitutional delay of puberty (CDP), also known as self-limited delayed puberty, refers to late onset of puberty with relatively normal progression afterward. In contrast, idiopathic hypogonadotropic hypogonadism (IHH) results in a long-lasting defect in reproductive endocrine activity. Both CDP and IHH are highly heritable and are sometimes observed in different family members in the same pedigree. Previous work by our group and others has suggested genetic overlap between the two conditions. In this study, we aimed to identify specific IHH-related genes that are also genetic causes of CDP. Methods: The Delayed Puberty Consortium assembled exome data for 233 individuals of diverse ancestries with CDP, with onset of puberty between 12 and 18 y in girls and between 13.5 and 18 y in boys. For control data, we used exome sequencing data from gnomAD v2.1.1 (n=125,748). After data harmonization and quality control, we used a modification of the “TRAPD” method to perform gene-based burden testing for 63 genes associated with IHH. We analyzed rare variants (minor allele frequency < 0.01) with high impact (premature stop, frameshift, start-lost, stop-lost) in all individuals across ancestries (n=233), as allele frequencies for high-impact variants are unlikely to vary widely across populations. We also analyzed rare variants with moderate impact (missense, inframe insertions/deletions) predicted to be deleterious by the Primate AI algorithm (score >0.6) in non-Finnish European (NFE) individuals with CDP (n=99), then meta-analyzed the results for high- and moderate-impact variants. We considered p-values < 7.9 x 10-4 (0.05 with Bonferroni adjustment for 63 genes) significant. Results: Of the 63 genes analyzed, SEMA3A (which encodes semaphorin-3A) exhibited significant enrichment for moderate-impact variants in the NFE CDP cohort compared to controls (variant frequency in CDP vs control: 0.064 vs 0.0076, p = 1.3 x 10-4) and in the meta-analysis of both high- and moderate-impact variants (p = 3.5 x 10-6). Novel SEMA3A variants identified exclusively in CDP individuals but not in controls were a frameshift variant, p.F546fsX2, and a missense variant, I252R. Also, three missense variants in SEMA3A were observed at a higher frequency in NFE CDP individuals compared with controls: p.R66T, p.V461A, and p.T717I. No other IHH genes showed significant enrichment of rare variants in the CDP cohort. Conclusion: Rare variants in SEMA3A contribute to both CDP and IHH. While functional studies are required to assess the effects of these specific variants on protein function, previous in vitro studies of similar SEMA3A variants demonstrated defects in secretion or signaling activity. Subsequent studies employing individual-level ancestry-matched controls and larger CDP cohorts are planned to identify additional genes that contribute to CDP. Presentation: 6/1/2024

12330 Rare Variants in SEMA3A in Individuals with Constitutional Delay of Puberty (CDP)

Abstract Disclosure: W. He: None. E.C. Schafer: None. R. Brauner: None. A. Delaney: None. L. Dunkel: None. R. Grinspon: None. J.E. Hall: None. J.N. Hirschhorn: None. S. Howard: None. A. Latronico: None. A.A. Jorge: None. K. McElreavey: None. V. Mericq: None. P.M. Merino: None. M.R. Palmert: None. R.A. Rey: None. R.C. Rezende: None. S.B. Seminara: None. N. Shaw: None. T. Delayed Puberty Genetics Consortium: None. Y. Chan: None. Background: Constitutional delay of puberty (CDP), also known as self-limited delayed puberty, refers to late onset of puberty with relatively normal progression afterward. In contrast, idiopathic hypogonadotropic hypogonadism (IHH) results in a long-lasting defect in reproductive endocrine activity. Both CDP and IHH are highly heritable and are sometimes observed in different family members in the same pedigree. Previous work by our group and others has suggested genetic overlap between the two conditions. In this study, we aimed to identify specific IHH-related genes that are also genetic causes of CDP. Methods: The Delayed Puberty Consortium assembled exome data for 233 individuals of diverse ancestries with CDP, with onset of puberty between 12 and 18 y in girls and between 13.5 and 18 y in boys. For control data, we used exome sequencing data from gnomAD v2.1.1 (n=125,748). After data harmonization and quality control, we used a modification of the “TRAPD” method to perform gene-based burden testing for 63 genes associated with IHH. We analyzed rare variants (minor allele frequency < 0.01) with high impact (premature stop, frameshift, start-lost, stop-lost) in all individuals across ancestries (n=233), as allele frequencies for high-impact variants are unlikely to vary widely across populations. We also analyzed rare variants with moderate impact (missense, inframe insertions/deletions) predicted to be deleterious by the Primate AI algorithm (score >0.6) in non-Finnish European (NFE) individuals with CDP (n=99), then meta-analyzed the results for high- and moderate-impact variants. We considered p-values < 7.9 x 10-4 (0.05 with Bonferroni adjustment for 63 genes) significant. Results: Of the 63 genes analyzed, SEMA3A (which encodes semaphorin-3A) exhibited significant enrichment for moderate-impact variants in the NFE CDP cohort compared to controls (variant frequency in CDP vs control: 0.064 vs 0.0076, p = 1.3 x 10-4) and in the meta-analysis of both high- and moderate-impact variants (p = 3.5 x 10-6). Novel SEMA3A variants identified exclusively in CDP individuals but not in controls were a frameshift variant, p.F546fsX2, and a missense variant, I252R. Also, three missense variants in SEMA3A were observed at a higher frequency in NFE CDP individuals compared with controls: p.R66T, p.V461A, and p.T717I. No other IHH genes showed significant enrichment of rare variants in the CDP cohort. Conclusion: Rare variants in SEMA3A contribute to both CDP and IHH. While functional studies are required to assess the effects of these specific variants on protein function, previous in vitro studies of similar SEMA3A variants demonstrated defects in secretion or signaling activity. Subsequent studies employing individual-level ancestry-matched controls and larger CDP cohorts are planned to identify additional genes that contribute to CDP. Presentation: 6/1/2024

7039 Isolated Gonadotropin Deficiency Transmitted From Mother to Daughter Conceived Through Assisted Reproduction Due Newly Identified, Autosomal Dominant Mutation Within the SOX10 Gene

Abstract Disclosure: S. Bakjaji: None. R.P. Hoffman: None. Title: Isolated gonadotropin deficiency transmitted from mother to daughter conceived through assisted reproduction due newly identified, autosomal dominant mutation within the SOX10 gene. Objectives: We report a case of genetic isolated gonadotropin deficiency occurring in a mother and in her daughter conceived through assisted reproductive technology using mother’s ovum. Methods Case report Results: The daughter was initially seen at 12 years 0 months for evaluation of short stature and concerns she had not grown in the last year. She was otherwise in good health and reported normal sense of smell. At the time of assessment, her height was 132.6 cm (0.61 percentile; Z=-2.5). The mother had been diagnosed with Kallmann’s syndrome and achieved pregnancy through ovarian stimulation. Her height was 152.4 cm, while the father's height was 177.8 cm. Two male siblings were born at the same time and were in normal health. Physical examination of the daughter was unremarkable. She had Tanner stage 1 pubic hair and Tanner stage 1 breasts. The growth chart displayed a notable deceleration in growth Laboratory results showed normal free T4 of (0.9 ng/dL) with slightly elevated TSH (8.348 uIU/mL), positive thyroid antibodies, normal IGFI at 164 ng/mL (normal range for Tanner I: 54 - 301) and IGFBP-3 at 5.8 ug/mL (2.4 - 8.4 ug/mL). The karyotype was 46 XX. Her peak growth hormone using glucagon-arginine stimulation was 12.8 ng/ml. When no pubertal development was seen over the next 6 months, GnRH stimulation testing revealed baseline LH of 0.04 mIU/ml and a peak of 1.78 and baseline FSH of 0.41 mIU/ml with a peak of 2.83. Bone age was 8 years 4 months.Over the next year her growth velocity was 4.8 cm/year and she remained prepubertal. Genetic testing done identified a new heterozygous sequence variant (c.226G>A) in the SOX10 gene which would lead to replacement of valine by isoleucine at position 76 and was thought to be damaging in silico. This variant was subsequently found to be shared with her mother but not her father. Conclusions: Most Kallmann’s syndrome or genetic isolated gonadotropin deficiency cases are due to autosomal dominant but spontaneous new mutations since infertility is usually present in those with the syndrome. This case emphasizes the importance of genetic counselling regarding inheritance risk when assisted reproduction technology using maternal ovum is used. Presentation: 6/2/2024

7196 Variants in the Neurodevelopmental Gene BRINP2 are Associated with Severe Delayed Puberty

Abstract Disclosure: Y. Al-Sayed: None. R. Oleari: None. A. Cariboni: None. W. He: None. Y. Chan: None. S.R. Howard: None. Gonadotropin-releasing hormone (GnRH) is the master hormone regulating the reproductive axis and its pulsatile secretion is crucial for puberty onset and fertility. Disruption in GnRH neuron development or hypothalamic function can lead to absent or delayed puberty (DP) due to GnRH deficiency, with a phenotypic spectrum from severe delayed puberty to partial or complete Hypogonadotropic Hypogonadism (HH). HH can also be present as a shared trait with other neurodevelopmental disorders (NDDs). The aim of our study was to identify novel genetic etiology of severe DP by identifying variants in associated genes in our patient cohort; and ascertain the functional effects of identified variants of interest. Whole exome sequencing (WES) was performed on DNA samples from 180 probands with DP to identify potentially pathogenic rare coding variants in relevant gene pathways. Integrative analysis was performed on genomic data from human patients combined with transcriptomics analysis of rodent immortalized and primary GnRH neurons to determine novel regulators of GnRH neuronal development and function. Bone morphogenetic protein/retinoic acid inducible neural-specific 2 (BRINP2) was identified as a candidate gene of interest as it was found to be significantly upregulated during GnRH neuronal development in these single cell transcriptomics analyses. Mutations in this gene have been previously associated with NDDs such as autistic spectrum disorder (ASD). BRINP2 is localised to the olfactory bulb, a key site during GnRH neuron migration. Copy number variation in this gene is seen in multiple individuals from the Deciphering Developmental Disorders study with a phenotype including cryptorchidism and intellectual disability (https://www.deciphergenomics.org/gene/BRINP2/patient-overlap/cnvs). WES analysis identified four variants in BRINP2 (p.R726W, p.R649Q, p.I629V and p.D729N) in four unrelated probands with severely DP or partial HH, in combination with ASD or other NDD features. These four variants are all rare or ultra-rare and are predicted to be pathogenic by in silico tools including CADD, REVEL and SIFT. Protein expression of the four mutants was comparable to the reference protein. BRINP2 has been shown to inhibit neuronal cell proliferation by negative regulation of cell cycle transition and Brinp2 knockout mice show hyperactive behaviour representative of human attention-deficit hyperactivity disorder, but pubertal timing has not been assessed. Thus, BRINP2 is a novel candidate for GnRH deficiency with NDD and we have investigated the role of BRINP2 in GnRH biology via wildtype and mutant protein sub-cellular localization, as well as tissue expression in mouse hypothalamic tissue across development. Presentation: 6/2/2024

7640 The first description of an MC4R variant in a patient with Kallmann syndrome and obesity

Abstract Disclosure: A.A. Aslam: None. S. Lim: None. R. Willemsen: None. K. Koysombat: None. M. Young: None. W.S. Dhillo: None. A. Abbara: None. S. Howard: None. E.F. Gevers: None. Introduction: Pathogenic MC4R gene variants result in hyperphagia and early onset obesity but puberty is not usually affected. We describe an MC4R variant in a patient with Kallmann syndrome and obesity. A 16 year old male with repaired Tetralogy of Fallot, anosmia, autism and anxiety, was referred with obesity and delayed puberty. His birth weight was 3360 g (-0.26 SDS). Height was -1.31 SDS, BMI 30.7 kg/m2. He had high arched palate, normal skin and hair colour, mild hypertelorism and upward slanting palpebral fissures. Pubertal staging was A2P1G1 5ml testes bilaterally. Results: LHRH test showed borderline low peaks (LH 5.0 U/L, FSH 2.6 U/L) and inhibin B 108 pg/mL (25-325 pg/mL). MRI brain showed hypoplastic olfactory bulbs, absent olfactory sulci and normal pituitary anatomy. CGH microarray, karyotype and the UK hypogonadism gene panel were normal. He underwent whole genome sequencing in the Genetic Factors Affecting the Timing of Puberty Study; no abnormalities in 52 known genes associated with GnRH deficiency were found but a previously described heterozygous variant was detected, MC4R c.542G>A, p.Gly181Asp, classified pathogenic and absent in control databases. Management: He was commenced on Testosterone but showed progression of testicular size to 10 mL and testosterone was stopped but required restarting. Repeat investigations off treatment, aged 22 years (height 178 cm, BMI 42 kg/m2, testes 15 mL): inhibin B 66 pg/mL, testosterone 2 nmol/L, baseline LH 2.4 U/L, stimulated peak 24.9 U/L, baseline FSH 1.2 U/L, stimulated peak 4.2 U/L. Cortisol and IGF1 were in the normal range. He also developed autoimmune hypothyroidism with raised TPO antibodies (TSH 24.7 mU/L, FT4 5.6 pmol/L). Discussion: Previous in vitro work has shown complete loss of function of MC4R p.Gly181Asp due to reduced cell surface expression and reduced binding to a-MSH. Heterozygous p.Gly181Asp variants have been described in several children/adults with obesity; but hypogonadism in heterozygous carriers has not. Homozygous MC4R p.Gly181Asp was found in a male with obesity and partial HH thought to be due to abnormal GnRH production but with normal olfactory bulbs. We are the first to describe a heterozygous MC4R p.Gly181Asp variant in a patient with partial hypogonadism and anosmia with hypoplastic bulbs in addition to obesity. Interaction between POMC-MC-leptin circuits and Kisspeptin-GnRH circuits is recognised although not completely understood. Previous work has shown that a subset of kisspeptin neurons express MC4R and that KNDy neurones receive synaptic input from POMC neurons. In addition, inhibition of MC4R/MC3R results in delayed onset of puberty in rats. Our results support a role for MC4R in GnRH secretion and potentially olfactory /GnRH neuronal migration. Assessment of spontaneous gonadotrophin production and response of gonadotrophin production to kisspeptin stimulation is currently in progress. Presentation: 6/1/2024

7407 Normosmic Idiopathic Hypogonadotropic Hypogonadism in Women: A Case Report and Comprehensive Review

Abstract Disclosure: E.G. Bustamante: None. M. Sulehri: None. I. Patoli: None. A. Karunakaran: None. Normosmic Idiopathic Hypogonadotropic Hypogonadism (nIHH) in Women: A Case Report and Literature ReviewIntroduction: IHH is a rare genetic disorder affecting gonadotropic-releasing hormone (GnRH) production and/or action, resulting in diminished sex steroid levels. Characterized by the absence of spontaneous pubertal development. In women, it manifests with normal adrenarche but absent thelarche and menarche. Our case highlight a late diagnosis of IHH in a 34-year-old woman with primary amenorrhea. Case report: A 34 year old lady with a history of primary amenorrhea sought evaluation. At age 16, she underwent assessment for short stature and primary amenorrhea, denying anosmia, headache, visual disturbances. Evaluation revealed bone age concordant with chronological age and normal MRI Brain. Pelvic ultrasound (US) showed small premenarchal uterus and ovaries. She initiated oral contraceptive pills (OCP) and experienced regular menses. Seeking fertility assistance at age 24, a normal Hysterosalpingogram was followed by successful delivery of twins after ovarian stimulation. Post-delivery menses did not resume and OCP was not restarted. Family history revealed a sister with irregular periods requiring OCP.Subsequently workup at age 30 showed Estradiol 22 pg/ml, FSH/LH 4.1/2.3 mUI/mL; normal PRL, TFT, DHEAS, 17OHP. Repeat Pelvic US showed normal uterus, endometrial stripe normal at 0.24 cm and non-visualized ovaries. PCOS testing negative for hyperandrogenism. Progesterone challenge resulted in no withdrawal bleeding. Brain MRI demonstrated a 2.2 x 1.3 mm hypoenhancing ovoid mass in the pars Intermedia of the pituitary gland suggestive of pituitary microadenoma. Pituitary axis hormonal testing was normal. Karyotype revealed 46 XX (normal female). Genetic evaluation identified a pathogenic variant (p.R35C) in GNRH1 gene. Her final diagnosis: nIHH. Discussion HH is diagnosed in 5% of all women with primary amenorrhea and is divided into 2 major categories: Kallmann syndrome and nIHH. The majority of known causes of HH can be attributed to mutations in KAL1, FGFR1, or GNRHR. The p.R35C variant has been associated with autosomal dominant nIHH. Diagnosis involves clinical suspicious, low LH/FSH and sex steroid levels, normal hypothalamic–pituitary imaging, and exclusion of differentials.Treatment goal for female focus on regular breast and uterine development, as well as the capability to conceive. Use of hormonal replacement therapy and/or gonadotropins or pulsatile GnRH for ovarian stimulation are essential. ConclusionWhile IHH predominantly affects men, limited literature explores its manifestation in women and its impact on fertility. The identification of a GNRH1-related nIHH variant highlights the role of genetic testing in specific HH diagnoses. Failure to diagnose in adolescence may compromise women overall well-being Presentation: 6/1/2024

A heterozygous SPRY4 variant identified in female infertility characterized by reduced oocyte potential and early embryonic arrest.

Can novel genetic factors contributing to early embryonic arrest in infertile patients be identified, along with the underlying mechanisms of the pathogenic variant? We identified a heterozygous variant in the SPRY4 (sprouty RTK signaling antagonist 4) in infertile patients and conducted in vitro and in vivo studies to investigate the effects of the variant/deletion, highlighting its critical role in female reproductive health. SPRY4 acts as a negative regulator of receptor tyrosine kinases (RTKs) and functions as a tumor suppressor. Its abnormal expression can lead to recurrent miscarriage by affecting trophoblast function. In mice, Spry4 knockout (KO) leads to craniofacial anomalies and growth defects. A human study links the SPRY4 variant to a male patient with isolated hypogonadotropic hypogonadism (IHH), hypothetically impacting gonadotropin-releasing hormone (GnRH) neurons, and causing reproductive dysfunctions. SPRY4 is thus potentially integral in regulating endocrine homeostasis and reproductive function. To date, no study has reported SPRY4 variants associated with female fertility, and a causal relationship has not been established with functional evidence. Whole-exome sequencing (WES) was performed in 392 infertile women who suffered from primary infertility of unknown reason, and the heterozygous SPRY4 variant were identified in one independent family. The infertile patients presenting were recruited from July 2017 to November 2023. Women diagnosed with primary infertility were recruited from the Reproduction Center of Zhongshan Hospital, Fudan University. Genomic DNA was extracted from peripheral blood for WES analysis. The SPRY4 variant were identified through WES, in silico analysis, and variant screening. All variants were confirmed by Sanger sequencing. The effects of the variants were investigated in human embryonic kidney (HEK) 293T (HEK293T) cells via western blotting, and in mouse oocytes and embryos through complementary RNA (cRNA) injection, RNA sequencing, fluorescence, absorbance, and RT-qPCR assays. Gene function was further examined in Spry4 KO mice via histology, western blotting, ELISA, and RT-qPCR assays. We identified a missense heterozygous pathogenic variant in SPRY4 (GRCh38, GenBank: NM_030964.5, c.157C>T p.(Arg53Trp), rs200531302) that reduces SPRY4 protein levels in HEK293T cells and disrupts the redox system and mitochondrial function in mouse oocyte, and perturbs developmental potential in mouse embryos. These phenotypes could be partially reversed by the exogenous addition of Nrf1 cRNA. Additionally, Spry4-/- mice exhibit ovarian oxidative stress and decreased ovarian function. Due to the limited WES data and population, we identified only one family with a SPRY4 mutation. The deeper mechanism and therapeutic strategy should be further investigated through mutant mice and recovery experiment. Our study has identified a pathogenic variant in SPRY4 associated with early embryonic arrest in humans. These findings enhance our understanding of the role of SPRY4 in early embryonic development and present a new genetic marker for female infertility. This work was supported by the National Natural Science Foundation of China (82071643 and 82171655) and Natural Science Foundation of Shanghai (22ZR1456200). None of the authors have any competing interests. N/A.

Evaluation of testicular volume in males with congenital hypogonadotropic hypogonadism: a comparative analysis.

Estimating accurate testicular volume (TV) of congenital hypogonadotropic hypogonadism (CHH) individuals is challenging due to the typically small testicular size. Ultrasound (USG) emerges as a vital solution, enabling precise measurements and reproducible results. The purpose of the study was to assess the three-dimensional measurement of the testis using USG and its volume was estimated using Ellipsoid (E) and Lambert (L) formulae and compared these with the TV by Prader orchidometer (OrTV). This is an exploratory analysis of data taken from a clinical trial conducted from May 2022 to March 2024 which included 94 testes from 47 CHH participants. The OrTVs and USGTVs were assessed at baseline and every three months till the completion of the study making a total of 348 observations. The three-dimensional measurement of the testes was noted and TVs were calculated using the above formulae. The mean age of the participants was 25.8 ± 6.14 years with a mean height of 169.9 ± 8.42 cm and body mass index (BMI) of 22.4 ± 4.72 kg/m2. The baseline mean OrTV, USGTV(E) and USGTV(L) were 2.15 ± 0.79 ml, 0.69 ± 0.43 ml and 0.93 ± 0.59 ml respectively. The smallest OrTV observed was 1 ml with its respective mean USGTV of 0.41 ± 0.2 ml(E) and 0.56 ± 0.27 ml(L). An OrTV of 4 ml had a mean USGTV of 1.11 ± 0.42 ml(E) and 1.51 ± 9.57 ml(L). At spermatogenesis, the mean OrTV was 8.84 ± 3.13 ml with the USGTV determined to be 4 ± 1.46 ml(E) and 5.46 ± 1.99 ml(L). The study revealed that all CHH patients at diagnosis had OrTV < 4 ml. This corresponds to a USG TV cut-off of 1.11 ml using the Ellipsoid formula and 1.51 ml with the Lambert formula, which could serve as a USG diagnostic criterion for CHH.

Expanding the Spectrum of Endocrine Abnormalities Associated with SOX11-related Disorders.

SOX11 variants cause Coffin-Siris Syndrome (CSS), characterized by developmental delay, hypogonadotropic hypogonadism (HH), skeletal and facial defects. To examine the contribution of SOX11 variants to the pathogenesis of Idiopathic Hypogonadotropic Hypogonadism (IHH), a disorder caused by hypothalamic GnRH deficiency. The Reproductive Endocrine Unit and the Pediatric Endocrinology Division, Massachusetts General Hospital. A cohort of 1810 unrelated IHH probands. Exome sequencing data from the entire cohort were examined for SOX11 rare single nucleotide variants (SNVs) [minor allele frequency in the gnomAD database <0.1%]. Rare SOX11 variant association testing was performed between the IHH and gnomAD population. Phenotyping of individuals harboring pathogenic/likely pathogenic SNVs (determined by the ACMG criteria) was performed. Four pathogenic SOX11 SNVs were identified in 5 IHH probands. The IHH cohort was enriched for SOX11 protein truncating SNVs (frameshift/nonsense) across the entire protein (2 SNVs in 3 IHH cases [p.S303X (de-novo); p.S345Afs*13]; p 0.0004981) and for SOX11 missense SNVs within the SOX11-high-mobility group (HMG) domain (2 SNVs in 2 IHH cases p.G84D[de-novo]; p.P114S; p=0.00313922). The phenotypic spectrum of SOX11 variant carriers revealed additional endocrine defects including anosmic and normosmic forms of IHH, growth-hormone deficiency, pituitary and hypothalamic structural defects, and hypothyroidism. A pathogenic SOX11 SNV was also identified in a patient with functional HH (FHH, p.R100Q). CSS-associated features were present in 4/5 probands. Deleterious SOX11 variants cause IHH and other pituitary hormone deficiencies, suggesting that the human SOX11-associated disorder may stem from both hypothalamic and pituitary level defects.

Pregnancy induction with pulsatile gonadotropin releasing hormone pump (GNRH) therapy in a patient with a KISS1 receptor mutation associated normosmic congenital hypogonadotropic hypogonadism and a very low anti-mullerian hormone: a case study

Pregnancy induction with pulsatile gonadotropin releasing hormone pump (GNRH) therapy in a patient with a KISS1 receptor mutation associated normosmic congenital hypogonadotropic hypogonadism and a very low anti-mullerian hormone: a case study