Luteinizing Hormone/chorionic Gonadotropin Receptor Gene Research Articles

Effect Modification of LHCGR Gene Variant (rs2293275) on Clinico-Biochemical Profile, and Levels of Luteinizing Hormone in Polycystic Ovary Syndrome Patients.

Polycystic ovary syndrome (PCOS) is a common multifaceted endocrine disorder among reproductive-aged women. Deranged luteinizing hormone levels and associated downstream signaling cascade mediated by its receptor luteinizing hormone chorionic gonadotropin receptor (LHCGR) are pivotal in the etiopathogenesis of PCOS. Genetic variations in the LHCGR have been associated with PCOS risk. However, the results are mixed and inconclusive. We evaluated the association of the LHCGR rs2293275 polymorphic variant with PCOS risk and its association with clinico-biochemical features of PCOS. 120 confirmed PCOS cases and an equal number of age-matched controls were subjected to clinical, biochemical, and hormonal investigations. Genotyping for rs2293275 was performed using polymerase chain reaction-restriction fragment length polymorphism. Logistic regression models were used to calculate odds ratios (ORs) at 95% confidence intervals (95% CIs). In the current study, PCOS cases reported a lower number of menstrual cycles per year than respective controls. A significantly higher BMI, Ferriman Galway score, levels of serum testosterone, insulin, TSH, FSH, and fasting glucose were observed in cases than in controls (p < 0.01). Compared to GG carriers, we observed a higher risk of developing PCOS in the subjects who harbored GA (OR 10.4, p < 0.0001) or AA (OR 7.73, p = 0.02) genotype. The risk persisted in the dominant model (GA + AA) as well (OR 10.29, p = 0.01). On stratification, a higher risk of developing PCOS was observed in variant genotype carriers who had a family history of either type two diabetes mellitus (OR 117; p < 0.0001) or hirsutism (OR 79; p < 0.0001). We also found significantly elevated levels of serum LH levels in the subject harboring GA and AA genotypes when compared to GG carriers. In the present study, we report a significant association of the LHCGR rs2293275 variant with the PCOS risk.

SUN-LB15 A Case of Familial Male-Limited Precocious Puberty With a Novel Mutation

Introduction:Familial Male-Limited Precocious Puberty (FMPP), also known as testotoxicosis, is a rare cause of precocious puberty in males. It is caused by a mutation in the luteinizing hormone/chorionic gonadotropin receptor (LHCGR) gene, resulting in the receptor to be constitutively activated. This results in precocious puberty in males with rapid skeletal maturation and compromised final adult height if not treated. A combination on anti-androgens and aromatase inhibitors are the mainstay of treatment.Case:A 16-month-old male presented to our clinic due to concerns of precocious puberty. Pubic hair was noted at 6 months of age along with rapid growth acceleration. There was no known exposure to testosterone and no family history of early puberty or subnormal adult height. Upon presentation, his height was over the 99th percentile while his target height is at the 50th percentile. Physical examination revealed prepubertal testes with pubic hair at Tanner stage II. A bone age was reported as 12-18 months at a chronologic age of 12 months. Initial lab evaluation revealed normal serum levels of 17 OHP, androstenedione and DHEA-S with a slightly elevated serum LH (0.7mIU/ml), and very elevated serum testosterone level (289ng/dl). Leuprolide and ACTH stimulation tests as well as MRI of the abdomen and pelvis were normal. Serum levels of AFP, β-hCG and IGF-1 were also normal. Bone age advanced to 6 years at a chronological age of 21 months and to 8 years by 26 months of age. At 26 months of age, his stretched penile length measured 11cm. LH receptor testing was obtained, which revealed a novel heterozygous missense mutation in the LHCGR gene (c.1733A>C; p.Asp.578Ala). The mutation was reported to be a variant of unknown significance though likely in the pathological end of the spectrum by variant analysis with SIFT and PolyPhen. He was started on treatment with anastrozole 1 mg daily and bicalutamide 25 mg daily at 2 and 9/12 years of age. Pubertal progression, linear growth and skeletal maturation slowed down with treatment. His bone age remained stable at 13 years from the age of 2 and 10/12 years to 4 years old. Pubertal stage and stretched penile length have also remained stable on treatment. He is tolerating treatment well.Conclusion:We report a novel mutation in the LHCGR gene causing FMPP in a 6-month-old male who is responding very well to a combination of bicalutamide and anastrazole with marked decrease in growth velocity, pubertal progression and skeletal advancement.

Diseases caused by mutations in luteinizing hormone/chorionic gonadotropin receptor.

Accumulating evidence showed that the luteinizing hormone/chorionic gonadotropin receptor (LHCGR) is an essential regulator of sexual development and reproduction from zebrafish to human. Activating and inactivating mutations of LHCGR gene have been identified from patients of different phenotypes. Familial male-limited precocious puberty, Leydig cell hypoplasia, and empty follicle syndrome are caused by LHCGR mutations. More than 50 mutations have been reported from subjects of different ethnic backgrounds. Functional analyses of the mutant LHCGR revealed multiple defects, including cell surface expression, ligand binding, and signaling. The difference of the two native ligands and signaling pathway activated by LHCGR are illustrated. Potential therapeutic implications from the analyses of the naturally occurring LHCGR mutations, such as pharmacological chaperones, are highlighted.

MicroRNA miR-513a-3p acts as a co-regulator of luteinizing hormone/chorionic gonadotropin receptor gene expression in human granulosa cells

The luteinizing hormone/chorionic gonadotropin receptor (LHCGR) is essential for normal male and female reproductive processes. The spatial and temporal LHCGR gene expression is controlled by a complex system of regulatory mechanisms which are crucial for normal physiological function, especially during the female cycle. In this study, we aimed to elucidate whether microRNAs are involved in this network and play a role in regulating LHCGR expression. Computational analysis predicted that miR-513a-3p interacts with the LHCGR mRNA via three binding sites located in the 3′UTR region, enabling a synergistic action. Moreover, using a luciferase-based reporter assay we found that miR-513a-3p targets the LHCGR, resulting in a significant down-regulation of its expression. In human primary granulosa cell cultures we detected a dynamic, inversely associated expression pattern of miR-513a-3p and the LHCGR. In addition, transfection with miR-513a-3p or its specific inhibitor led to a down- or up-regulation at the LHCGR mRNA level, respectively. An increased amount of miR-513a-3p resulted in the down-regulation of the LHCGR mRNA, reflected by the attenuation of cAMP synthesis after hormonal stimulation. In conclusion, these data demonstrate that miR-513a-3p is involved in the control of the LHCGR expression by an inversely regulated mechanism at the post-transcriptional level and show for the first time that this kind of post-transcriptional process contributes to the multifaceted system of the human LHCGR regulation.

Aberrant transcription of the LHCGR gene caused by a mutation in exon 6A leads to Leydig cell hypoplasia type II

Introduction: Male fetal sex differentiation is dependent on the androgen production of fetal testicular Leydig cells, which is induced by placental human chorionic gonadotropin. Later during gestation it is maintained by luteinizing hormone, secreted by the fetal pituitary gland. As the action of both glycoprotein hormones is mediated by the luteinizing hormone/chorionic gonadotropin receptor (LHCGR), this receptor is essential for male sex differentiation as well as for normal reproductive function in the adult.

Aberrant transcription of the LHCGR gene caused by a mutation in exon 6A leads to Leydig cell hypoplasia type II

The luteinizing hormone/chorionic gonadotropin receptor (LHCGR) is essential for normal male sex differentiation. Recently, the additional primate-specific exon 6A of the LHCGR was discovered and it was shown to act as regulatory element at the transcriptional level.Compound heterozygous mutations in exon 6A (c.580 A>G) and exon 11 (c.1244T>C) were identified in the LHCGR of a male 46,XY patient with genital malformation. Analysis revealed that mutation c.580A>G in exon 6A affects the splicing pattern resulting in an increase of transcripts containing the internal variants of exon 6A prone to nonsense-mediated decay. In contrast, mutation c.1244T>C results in an amino acid substitution (Ile415Thr), which abolishes signal transduction due to structural changes. When inherited in a compound heterozygous fashion these mutations result in Leydig cell hypoplasia (LCH) type II. Thus this study provides proof that mutations causing aberrant transcription can impair receptor function and thereby be causative of LCH.

A novel luteinizing hormone/chorionic gonadotropin receptor mutation associated with amenorrhea, low oocyte yield, and recurrent pregnancy loss

To study the cause for poor oocyte yield, amenorrhea, and recurrent pregnancy loss in a patient undergoing IVF. Case report. University-affiliated private IVF clinic. A 33-year-old woman with amenorrhea, recurrent ovarian cyst formation, poor oocyte yield, and repeated chemical pregnancies after IVF treatments. The hCG stimulation test and luteinizing hormone/chorionic gonadotropin receptor (LHCGR) gene sequencing. The presence of LHCGR gene mutations. The patient had a markedly abrogated androgen response to 10,000 IU of hCG. A novel heterozygous inactivating mutation in exon 1 of the LHCGR gene was detected. This mutation was superimposed on a common LHCGR polymorphism. This novel mutation may provide a potential genetic mechanism for the poor oocyte recovery in some IVF cases. It is the first example of a heterozygous inactivating mutation in the LHCGR gene.

Study on a pedigree with Leydig cell hypoplasia caused by novel mutation of luteinizing hormone receptor

Objective To investigate a Chinese pedigree suffering from Leydig cell hypoplasia ( LCH) based on clinical data and genetic diagnosis. Methods The patient was diagnosed by means of clinical data, hormone profiles, and human chorionic gonadotropin ( hCC) test. The luteinizing hormone/chorionic gonadotropin receptor(LHCGR) gene of the patient and family members was amplified and sequenced. Results The patient presented with male pseudohermaphroditism, low level of testosterone, which did not respond to hCG. Genetic analysis of the LHCGR revealed two novel mutations: a missense mutation located in exon 5, resulting in Ile replaced by Thr in the extracellular domain; and a splice site mutation in the 3' terminal of intron 6( IVS6-3 C→A). Proband's sister (46, XX) who lacked clinical manifestations showed the identical genotype with the patient. Conclusions A mutation in the consensus sequence of 3' splice site, in addition to a missense mutation (Ile 152Thr)in the extracellular ligand-binding domain is the cause of inactivation of the LHCGR gene in patient with Leydig cell hypoplasia. Key words: Luteinizing hormone/chorionic gonadotropin receptor; Male pseudohermaphroditism; Leydig cell hypoplasia

Polymorphisms of the luteinizing hormone/chorionic gonadotropin receptor gene: association with maldescended testes and male infertility

Maldescended testes are the most common genital anomaly in newborns and are associated with testicular malignancy and infertility. As the inguinoscrotal phase of testis descent is androgen-dependent and requires integrity of the luteinizing hormone/chorionic gonadotropin receptor (LHCGR), we investigated whether nonsynonymous polymorphisms of the LHCGR gene are associated with maldescended testes. This was a retrospective case-control study including 278 patients with maldescended testes, 277 infertile men without maldescensus and 271 controls with normal sperm concentrations. Clinical and endocrinological workup of the patients was performed. Single nucleotide polymorphism (SNP) analysis was performed by GeneScan and TaqMan technology. Men with maldescended testes had significantly lower testis volumes, higher serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) but similar testosterone levels compared with both the control groups. The insLQ polymorphism in exon 1 (rs4539842) and the N291S SNP in exon 10 (rs12470652), showing increased receptor sensitivity in vitro, were not differently distributed between patients and controls. The S312N SNP in exon 10 (rs2293275) was significantly less frequent in men with maldescended testes than in controls. This difference was confirmed when infertile men with and without maldescensus were considered together. In men with maldescensus, a high LH drive maintains normal testosterone levels but this LH resistance is not associated with any particular LHCGR genotype. A significant association with the S312N polymorphism in exon 10 of the LHCGR is correlated to the spermatogenetic damage rather than to the maldescensus itself. Either the LHCGR itself or another genomic region linked to this SNP, possibly the germ cell-specific TFIIA-alpha/beta-like factor gene transcribed from the same genomic region in the opposite direction, is a risk factor for male infertility.