XY Partial Gonadal Dysgenesis Research Articles

A Case Report of 46 XY Partial Gonadal Dysgenesis with Dual Gonadal Tumours

46XY gonadal dysgenesis is known as a disorder of sex development (DSD) that occurs due to abnormality in gonadal development. There is a conflict between one’s genotype, phenotype, and gonadal development, which influences the wide range of presentation and clinical appearance of 46XY females. This was a case of a 46XY female who presented with primary amenorrhea with delayed puberty at the age of 18 years old. She had ambiguous genitalia. Her breast and pubic hair were at Tanner Stage 2. Transabdominal ultrasound found a small uterus with a vagina; however, the gonads were not seen. A magnetic resonance imaging (MRI) showed a 20mm right gonad located extra-pelvis near the right iliac vessels while the 9mm streak left gonad was at the usual location next to the sigmoid colon. All her tumour markers were normal except lactate dehydrogenase (LDH) was elevated. She was given estrogen therapy for pubertal induction and underwent laparoscopy prophylactic bilateral gonadectomy. The intraoperative findings were similar to the MRI findings, and the histopathology examination (HPE) results showed left gonadoblastoma and right dysgerminoma FIGO stage 1A. She continued taking estrogen therapy until she had withdrawal bleeding, and oral progesterone was added. 46XY-DSD has high risk of developing germ cell tumour and requires prophylactic gonadectomy as soon as the diagnosis is established. However, delay in presentation and surgery may affect the outcomes and prognosis.

NR5A1-related 46,XY partial gonadal dysgenesis: A case report and literature review

Rationale: Disorders/differences of sex development (DSD) include a diverse group of congenital conditions in which the development of chromosomal, gonadal, or anatomical sex is discordant. It involves several variant genes, and one of them is NR5A1. NR5A1 encodes a signal transduction regulator in the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenal pathway, and pathogenic mutation in this gene is a cause of 46,XY DSD. Patient concerns: A 12-year-old individual raised as a girl was admitted to the hospital due to hirsutism and a deep voice that began at 11 years old. The individual exhibited testicular hypoplasia, clitoral hypertrophy, and female external genitalia. Diagnoses: The patient was diagnosed 46,XY partial gonadal dysgenesis. The cytogenetics revealed a 46,XY karyotype and DNA sequencing shown a variant in NR5A1. Pelvic magnetic resonance imaging showed absence of uterus and ovaries. The abdominopelvic ultrasound revealed bilateral testicle in bilateral groin. Pathology confirmed testes dysgenesis. Interventions: The patient underwent bilateral orchiectomy at age 12 years and was given a feminizing hormonal treatment of 0.5 mg/day of estradiol valerate tablets. Outcomes: The patient recovered well after surgery and hormonal treatment and had a regression in hirsutism and clitoromegaly. Lessons: 46,XY DSD is a rare disease that the development of chromosomal, gonadal, or anatomical sex is discordant, when diagnosed 46,XY DSD, the identification of an NR5A1 variant should be considered.

A Novel Look at Dosage-Sensitive Sex Locus Xp21.2 in a Case of 46,XY Partial Gonadal Dysgenesis without NR0B1 Duplication

A region of 160 kb at Xp21.2 has been defined as dosage-sensitive sex reversal (DSS) and includes the NR0B1 gene, considered to be the candidate gene involved in XY gonadal dysgenesis if overexpressed. We describe a girl with 46,XY partial gonadal dysgenesis carrying a 297 kb duplication at Xp21.2 upstream of NR0B1 initially detected by chromosomal microarray analysis. Fine mapping of the breakpoints by whole-genome sequencing showed a tandem duplication of TASL (CXorf21), GK and partially TAB3, upstream of NR0B1. This is the first description of an Xp21.2 duplication upstream of NR0B1 associated with 46,XY partial gonadal dysgenesis.

MYRF: A New Regulator of Cardiac and Early Gonadal Development-Insights from Single Cell RNA Sequencing Analysis.

De novo variants in the myelin regulatory factor (MYRF), a transcription factor involved in the differentiation of oligodendrocytes, have been linked recently to the cardiac and urogenital syndrome, while familiar variants are associated with nanophthalmos. Here, we report for the first time on a patient with a de novo stop-gain variant in MYRF (p.Q838*) associated with Scimitar syndrome, 46,XY partial gonadal dysgenesis (GD) and severe hyperopia. Since variants in MYRF have been described in both 46,XX and 46,XY GD, we assumed a role of MYRF in the early development of the bipotential gonad. We used publicly available single cell sequencing data of human testis and ovary from different developmental stages and analysed them for MYRF expression. We identified MYRF expression in the subset of coelomic epithelial cells at stages of gonadal ridge development in 46,XX and 46,XY individuals. Differential gene expression analysis revealed significantly upregulated genes. Within these, we identified CITED2 as a gene containing a MYRF binding site. It has been shown that Cited2−/− mice have gonadal defects in both testis and ovary differentiation, as well as defects in heart development and establishment of the left–right axis. This makes MYRF a potential candidate as an early regulator of gonadal and heart development via upregulation of the transcriptional cofactor CITED2.

Fertility in Individuals with Differences in Sex Development: Provider Knowledge Assessment

ObjectiveInfertility is common among individuals with differences in sex development (DSD), and affected individuals and families desire fertility counseling. This survey sought to assess fertility knowledge and experiences with fertility counseling among DSD specialists for DSD conditions excluding congenital adrenal hyperplasia. Design, Setting, Participants, and MeasuresA survey was iteratively developed by members of the DSD-Translational Research Network (DSD-TRN) Fertility Preservation Workgroup and disseminated to 5 clinician groups: the DSD-TRN, the Society for Pediatric Psychology DSD Special Interest Group (SIG), the Pediatric Endocrine Society DSD-SIG, the Societies for Pediatric Urology, and the North American Society for Pediatric and Adolescent Gynecology. ResultsCompleted surveys (n = 110) were mostly from pediatric urology (40.3%), gynecology (25.4%), and endocrinology (20.9%) specialists. Most (73/108, 67.6%) respondents reported discussing fertility potential. Sixty-seven responded to questions regarding fertility potential. Many participants answered questions about the presence of a uterus in individuals with 46,XY complete gonadal dysgenesis and about the potential for viable oocytes in individuals with 46,XY partial gonadal dysgenesis incorrectly. Comments acknowledged the need for further education on fertility in individuals with DSD. ConclusionsMany DSD providers have some knowledge of fertility potential, but knowledge gaps remain. Experts expressed a desire for education and accessible resources to counsel effectively about fertility potential for individuals with DSD.

Association between Down Syndrome and Disorders of Sex Development: Report of Three Cases and Review of 188 Cases in the Literature

In this study, we present 3 cases of Down syndrome (DS) associated with disorders/differences of sex development (DSD) and review the literature on this topic. Case 1: 1-year-old child with male genitalia and DS phenotype, 47,XX,+21 karyotype and testicular DSD. Case 2: 11-month-old child with male genitalia and few DS dysmorphisms, 45,X/47,XY,+21 karyotype, and mixed gonadal dysgenesis. Case 3: 4-month-old child with female genitalia and DS phenotype, 47,XY,+21 karyotype and XY complete gonadal dysgenesis. In the literature, among 188 patients, 107 (57%) had Klinefelter syndrome and 61 (33%) Turner syndrome, 12 (6%) had mixed gonadal dysgenesis, 2 (1%) had partial androgen insensitivity, 2 (1%) ovotesticular DSD, and the others had congenital adrenal hyperplasia, XY partial gonadal dysgenesis, XY complete gonadal dysgenesis, and complete androgen insensitivity (1 case each). A typical DS phenotype was found in all individuals of the revision, with the exception of one case, but DSD features were not always reported. In conclusion, the association of DS with sex chromosome DSD is the most frequently observed, whereas associations with 46,XX and 46,XY DSD is extremely rare.

NR5A1 c.991-1G>C splice-site variant causes familial 46,XY partial gonadal dysgenesis with incomplete penetrance.

The study aimed to identify the genetic basis of partial gonadal dysgenesis (PGD) in a non-consanguineous family from Estonia. Cousins P (proband) 1 (12years; 46,XY) and P2 (18years; 46,XY) presented bilateral cryptorchidism, severe penoscrotal hypospadias, low bitesticular volume and azoospermia in P2. Their distant relative, P3 (30years; 46,XY), presented bilateral cryptorchidism and cryptozoospermia. Exome sequencing was targeted to P1-P3 and five unaffected family members. P1-P2 were identified as heterozygous carriers of NR5A1 c.991-1G>C. NR5A1 encodes the steroidogenic factor-1 essential in gonadal development and specifically expressed in adrenal, spleen, pituitary and testes. Together with a previous PGD case from Belgium (Robevska et al 2018), c.991-1G>C represents the first recurrent NR5A1 splice-site mutation identified in patients. The majority of previous reports on NR5A1 mutation carriers have not included phenotype-genotype data of the family members. Segregation analysis across three generations showed incomplete penetrance (<50%) and phenotypic variability among the carriers of NR5A1 c.991-1G>C. The variant pathogenicity was possibly modulated by rare heterozygous variants inherited from the other parent, OTX2 p.P134R (P1) or PROP1 c.301_302delAG (P2). For P3, the pedigree structure supported a distinct genetic cause. He carries a previously undescribed likely pathogenic variant SOS1 p.Y136H. SOS1, critical in Ras/MAPK signalling and foetal development, is a strong novel candidate gene for cryptorchidism. Detailed genetic profiling facilitates counselling and clinical management of the probands, and supports unaffected mutation carriers in the family for their reproductive decision making.

Clinical and molecular characteristics of patients with 46,XY DSD due to NR5A1 gene mutations

Steroidogenic factor 1 (SF1, NR5A1) is a nuclear receptor that regulates multiple genes involved in adrenal and gonadal development, steroidogenesis, and the reproductive axis. Human mutations in SF1 were initially found in patients with severe gonadal dysgenesis and primary adrenal failure. However, more recent case reports have suggested that heterozygous mutations in SF1 may also be found in patients with 46,XY partial gonadal dysgenesis and underandrogenization but normal adrenal function. We have analyzed the gene encoding SF1 (NR5A1) in a cohort of 310 Russian patients with 46,XY disorders of sex development (DSD). Heterozygous SF1 variants were found in 36 out of 310 (11.6%) of cases, among them 15 were not previously described. We have not found any phenotype-genotype correlations and any clinical and laboratory markers that would allow to suspect this type of before conducting molecular genetic analysis.

Incidence and diagnoses of disorders of sex development in proximal hypospadias

BackgroundEvidence-based guidelines on evaluation of boys with proximal hypospadias for the possibility of a disorder of sex development (DSD) have yet to be developed. We aimed to investigate the incidence and diagnoses of DSD in patients with proximal hypospadias. MethodsWe retrospectively reviewed the records of consecutive boys who underwent proximal hypospadias repairs from 2006 to Sept 2017. Data collected included scrotal anomaly, testes position/palpability, micropenis, DSD investigations, and surgical techniques. Results165 patients were eligible for the study. 14 (8.5%) were diagnosed to have DSD. The diagnoses were 46,XX testicular DSD [n = 1], 46,XY DSD [n = 7; partial gonadal dysgenesis (PGD) = 3; 5α-reductase type 2 deficiency = 3; 17α-hydroxylase deficiency = 1], Sex Chromosome DSD [n = 6; 45,X/46,XY PGD = 4; Klinefelter = 2]. 3/7 (43%) patients with PGD had gonadal germ cell neoplasms. Of the DSD patients, 6/14 (43%), 11/14 (79%) and 11/14 (79%) had undescended/impalpable testes, micropenis and penoscrotal transposition/bifid scrotum, respectively, significantly higher prevalence rates than those without DSD diagnosis (p-values <0.05). 10/14 (71.4%) DSD patients underwent 2-stage repair compared with 57/151 (37.7%) of others without DSD diagnosis (p = 0.01). ConclusionsPatients presenting with proximal hypospadias and one or more of the coexisting anomalies of micropenis, undescended/impalpable testes, and penoscrotal transposition/bifid scrotum should warrant DSD evaluation. Presence of bilaterally descended testes in scrotum does not preclude the possibility of DSD. Level of evidenceIV.

Long-term outcomes and molecular analysis of a large cohort of patients with 46,XY disorder of sex development due to partial gonadal dysgenesis.

Follow-up data on patients with 46,XY partial gonadal dysgenesis (PGD) until adulthood are scarce, making information on prognosis difficult. To analyse the long-term outcomes of patients with 46,XY PGD regarding testosterone production, germ cell tumour risk, genotype and psychosexual adaptation. A retrospective longitudinal study of 33 patients (20 assigned male and 13 patients assigned female at birth). Molecular diagnosis was performed by Sanger sequencing or by targeted massively parallel sequencing of 63 genes related to disorders of sex development (DSDs). Age at first and last visit ranged from 0.1 to 43 and from 17 to 53years, respectively. Spontaneous puberty was observed in 57% of the patients. During follow-up, six of them had a gonadectomy (four due to female gender, and two because of a gonadal tumour). At last evaluation, five of six patients had adult male testosterone levels (median 16.7nmol/L, range 15.3-21.7nmol/L) and elevated LH and FSH levels. Germ cell tumours were found in two postpubertal patients (one with an abdominal gonad and one patient with Frasier syndrome). Molecular diagnosis was possible in 11 patients (33%). NR5A1 variants were the most prevalent molecular defects (n=6), and four of five patients harbouring them developed spontaneous puberty. Gender change was observed in four patients, two from each sex assignment group; all patients reported satisfaction with their gender at final evaluation. Sexual intercourse was reported by 81% of both gender and 82% of them reported satisfaction with their sexual lives. Spontaneous puberty was observed in 57% of the patients with 46,XY PGD, being NR5A1 defects the most prevalent ones among all the patients and in those with spontaneous puberty. Gender change due to gender dysphoria was reported by 12% of the patients. All the patients reported satisfaction with their final gender, and most of them with their sexual life.

NR5A1 Loss-of-Function Mutations Lead to 46,XY Partial Gonadal Dysgenesis Phenotype: Report of Three Novel Mutations

Mutations in the NR5A1 gene, which encodes the steroidogenic factor 1 (SF1), are responsible for different phenotypes of disorders of sex development (DSD), such as bilateral anorchia and hypospadias. Furthermore, they can be associated with primary amenorrhea, premature ovarian failure, male infertility, adrenal tumors, and endometriosis. Direct sequencing of the 7 NR5A1 exons including ∼1,000 bp of the 5′-upstream and 3′-downstream regions and all intron-exon boundaries was performed in patients with DSD. Three different in silico tools were used to assess the consequences of a splice site mutation. As a result, 3 novel NR5A1 mutations were identified in 3 patients with 46,XY partial gonadal dysgenesis: p.Lys38* and p.Leu80Trpfs*8 lead to premature translation termination codons within the SF1 DNA-binding domain, and the intronic nucleotide substitution c.1138+1G>T at the intron 6 donor splice site is considered to modify correct splicing. We assume that the anomalous mRNA produced as a result of p.Lys38* and p.Leu80Trpfs*8 will be degraded by nonsense-mediated mRNA decay even before translation, leading to SF1 haploinsufficiency. The c.1138+1G>T mutation is expected to produce a truncated protein. Heterozygous SF1 loss-of-function mutations in these cases resulted in mild DSD manifestations, such as dysgenetic testes, spontaneous puberty, and preserved adrenal function.

408 Cases of Genital Ambiguity Followed by Single Multidisciplinary Team during 23 Years: Etiologic Diagnosis and Sex of Rearing

Objective. To evaluate diagnosis, age of referral, karyotype, and sex of rearing of cases with disorders of sex development (DSD) with ambiguous genitalia. Methods. Retrospective study during 23 years at outpatient clinic of a referral center. Results. There were 408 cases; 250 (61.3%) were 46,XY and 124 (30.4%) 46,XX and 34 (8.3%) had sex chromosomes abnormalities. 189 (46.3%) had 46,XY testicular DSD, 105 (25.7%) 46,XX ovarian DSD, 95 (23.3%) disorders of gonadal development (DGD), and 19 (4.7%) complex malformations. The main etiology of 46,XX ovarian DSD was salt-wasting 21-hydroxylase deficiency. In 46,XX and 46,XY groups, other malformations were observed. In the DGD group, 46,XY partial gonadal dysgenesis, mixed gonadal dysgenesis, and ovotesticular DSD were more frequent. Low birth weight was observed in 42 cases of idiopathic 46,XY testicular DSD. The average age at diagnosis was 31.7 months. The final sex of rearing was male in 238 cases and female in 170. Only 6.6% (27 cases) needed sex reassignment. Conclusions. In this large DSD sample with ambiguous genitalia, the 46,XY karyotype was the most frequent; in turn, congenital adrenal hyperplasia was the most frequent etiology. Malformations associated with DSD were common in all groups and low birth weight was associated with idiopathic 46,XY testicular DSD.

Long-Term Follow-Up of Patients with 46,XY Partial Gonadal Dysgenesis Reared as Males

Background/Aims. Studies on 46,XY partial gonadal dysgenesis (PGD) have focused on molecular, gonadal, genital, and hormone features; little is known about follow-up. Our aim was to analyze long-term outcomes of PGD. Methods. Retrospective longitudinal study conducted at a reference service in Brazil. Ten patients were first evaluated in the 1990s and followed up until the 2010s; follow-up ranged from 13.5 to 19.7 years. All were reared as males and had at least one scrotal testis; two bore NR5A1 mutations. Main outcomes were: associated conditions, pubertal development, and growth. Results. All patients had normal motor development but three presented cognitive impairment; five had various associated conditions. At the end of the prepubertal period, FSH was high or high-normal in 3/6 patients; LH was normal in all. At the last evaluation, FSH was high or high-normal in 8/10; LH was high or high-normal in 5/10; testosterone was decreased in one. Final height in nine cases ranged from −1.57 to 0.80 SDS. All had spontaneous puberty; only one needed androgen therapy. Conclusions. There is good prognosis for growth and spontaneous pubertal development but not for fertility. Though additional studies are required, screening for learning disabilities is advisable.

Screening of Y chromosome microdeletions in 46,XY partial gonadal dysgenesis and in patients with a 45,X/46,XY karyotype or its variants

BackgroundPartial and mixed gonadal dysgenesis (PGD and MGD) are characterized by genital ambiguity and the finding of either a streak gonad and a dysgenetic testis or two dysgenetic testes. The karyotype in PGD is 46,XY, whereas a 45,X/46,XY mosaicism or its variants (more than two lineages and/or structural abnormalities of the Y chromosome) is generally found in MGD. Such mosaics are also compatible with female phenotype and Turner syndrome, ovotesticular disorder of sex development, and infertility in men with normal external genitalia. During the last few years, evidences of a linkage between Y microdeletions and 45,X mosaicism have been reported. There are also indications that the instability caused by such deletions might be more significant in germ cells. The aim of this work was to investigate the presence of Y chromosome microdeletions in individuals with PGD and in those with 45,X/46,XY mosaicism or its variants and variable phenotypes.MethodsOur sample comprised 13 individuals with PGD and 15 with mosaicism, most of them with a MGD phenotype (n = 11). Thirty-six sequence tagged sites (STS) spanning the male specific region (MSY) on the Y chromosome (Yp, centromere and Yq) were analyzed by multiplex PCR and some individual reactions.ResultsAll STS showed positive amplifications in the PGD group. Conversely, in the group with mosaicism, six individuals with MGD had been identified with Yq microdeletions, two of them without structural abnormalities of the Y chromosome by routine cytogenetic analysis. The deleted STSs were located within AZFb and AZFc (Azoospermia Factor) regions, which harbor several genes responsible for spermatogenesis.ConclusionsAbsence of deletions in individuals with PGD does not confirm the hypothesis that instability of the Y chromosome in the gonads could be one of the causes of such condition. However, deletions identified in the second group indicate that mosaicism may be associated with Y chromosome abnormalities detectable only at the molecular level. If patients with mosaicism and Y microdeletions reared as males decide to undergo in vitro fertilization, Y chromosomes which tend to be unstable during cell division may be transmitted to offspring.

Laparoscopic gonadectomy of streak gonads within the inguinal canals in a patient with XY partial gonadal dysgenesis

A 33-year-old phenotypic female presented with primary amenorrhea. The physical examination revealed no breast development, scanty axillary and pubic hair, normal female external genitalia, and a short blind vagina. The findings of magnetic resonance imaging, karyotyping, and hormonal examinations supported the diagnosis of XY partial gonadal dysgenesis. Laparoscopic surgery showed that spermatic cords, including the bilateral streak gonads and epididymes, were within the inguinal canals. After opening the spermatic cords and identifying the lower borders of the streak gonads, the spermatic cords were transected at the level of the vas deferens. A prophylactic herniorrhaphy using polyprophylene mesh was performed due to weakening of the internal inguinal ring. Pathologic evaluation of the gonads confi rmed the diagnosis of partial gonadal dysgenesis without evidence of malignancy. A laparoscopic approach is feasible for treatment of XY gonadal dysgenesis, even if the streak gonads are present within the inguinal canal.

Novel DMRT1 3'UTR+11insT mutation associated to XY partial gonadal dysgenesis

The Y-chromosome-located SRY gene encodes a small testis-specific protein containing a DNA-binding motif known as the HMG (high mobility group) box. However, mutations in SRY are not frequent especially in cases of 46,XY partial gonadal dysgenesis. Several sex-determining genes direct the fate of the bipotential gonad to either testis or ovary. In addition, heterozygous small deletions in 9p can cause complete and partial XY gonadal dysgenesis without other symptoms. Human DMRT1 gene, which is located at 9p24.3, is expressed in testis and ovary and has been considered, among others, a candidate autosomal gene responsible for gonadal dysgenesis. In this report we describe a nucleotide insertion in DMRT1 3'UTR in a patient of XY partial gonadal dygenesis. The 3'UTR+11insT is located within a conserved motif important for mRNA stabilization.

46,XY and 45,X/46,XY testicular dysgenesis: similar gonadal and genital phenotype, different prognosis

The objective of this study was to describe the change in diagnosis and prognosis of a child with testicular dysgenesis and 46,XY karyotype after detection of a 45,X cell line and to discuss the difficulties caused by the terms mixed gonadal dysgenesis (MGD) and XY partial gonadal dysgenesis (XYPGD). One case was reported including clinical and laboratory findings of a child of 41-day-old infant with 1.3-cm phallus, penoscrotal hypospadias and left prepubertal testis. Karyotype 46,XY (16 cells), normal hormone levels. Right streak gonad, epididymis and müllerian remnants were removed; initial diagnosis was XYPGD. Persistent growth retardation led to further cytogenetic analysis (50 cells) and detection of a 45,X cell line. Detection of a 45,X lineage changed both the diagnosis to MGD and also the prognosis.The number of cells analyzed in karyotyping is critical. Use of MGD and XYPGD to designate both a histological picture and a syndromic diagnosis, results in lack of emphasis on clinical differences between 46,XY and 45,X/46,XY subjects.

Choix de sexe dans les dysgénésies gonadiques partielles XY (cas clinique)

XY patients with gonadal dysgenesis present with a wide array of clinical pictures that is characterised by a variable incomplete virilisation of the external genital organs (female phenotype, posterior hypospadias, cryptorchidism) and the persistence of the internal müllerian duct structures. The birth of a child with this type of abnormality is a social phenomenon, which will probably have a physical and psychical impact. The choice of the sex depends on the organic anatomy, diagnosis age, risk of gonadal tumors and the development possibilities (mainly at puberty) of the child. The registration of the civil status can be made only after determining the sex through the aforementioned anatomical and functional study. Once this process is finished, the treatment must be considered. We report our experience, particularly complicated in the choice of the sex of child, with an XY karyotype and partial gonadal dysgenesis. Raised as a girl until her seventh day when her parents noticed the existence of a genital bud and decided to register their child as a boy in the civil status. He was referred to our hospital, at the age of 16 months, in order to explore a bilateral cryptorchidism and posterior hypospadias. Our patient was declared to be a boy based on an unanimous opinion of a multidisciplinary team.

Mutations in the TSPYL1 gene associated with 46,XY disorder of sex development and male infertility

We screened 100 individuals with anomalies of testicular development or function for mutations in the TSPYL1 gene. A 46,XY female with complete gonadal dysgenesis carried a p.K320R mutation in the highly conserved NAP domain, and a 46,XY male with idiopathic azoospermia harbored a p.R89H mutation, and this data supports the hypothesis that mutations in TSPYL1 may contribute to anomalies of testicular development/function.

Association of deletion 9p, 46,XY gonadal dysgenesis and autistic spectrum disorder

Deletions of distal chromosome 9p24 are often associated with 46,XY gonadal dysgenesis and, depending on the extent of the deletion, the monosomy 9p syndrome. We have previously noted that some cases of 46,XY gonadal dysgenesis carry a 9p deletion and exhibit behavioural problems consistent with autistic spectrum disorder. These cases had a small terminal deletion of 9p with limited or no somatic anomalies that are characteristic of the monosomy 9p syndrome. Here, we present a new case of 46,XY partial gonadal dysgenesis and autistic spectrum disorder associated with a de novo deletion of 9p24 that was detected by ultra-high resolution oligo microarray comparative genomic hybridization. The deletion included the candidate sex-determining genes in the region DMRT1 and DMRT3. These data suggest that a gene responsible for autistic spectrum disorder is located within 9p24. It remains to be determined if the gonadal dysgenesis and autistic spectrum disorder are caused by a single gene or if they are caused by distinct genetic entities at 9p24.