LHCGR inactivating variants: single center experience and systematic review of phenotype-genotype of 46,XY and 46,XX patients.

BACKGROUND: The data on Leydig cell hypoplasia (LCH) resulting from biallelic Luteinizing hormone/chorionic gonadotropin receptor (LHCGR) inactivating variants is limited to case series. METHODS: We aim to describe our patients and perform systematic review of the patients with LHCGR inactivating variants in the literature. Detailed phenotype and genotype data of 3 patients from our centre and 85 (46,XY: 67; 46,XX: 18) patients from 59 families with LHCGR-inactivating variants from literature were described. RESULTS: Three 46,XY patients(age 6-18 years) from our centre, with two reared as females, had two novel variants in LHCGR. Systematic review (including our patients) revealed 72 variants in 88 patients. 46,XY patients (n=70, 56 raised as females) presented with pubertal delay (n=41) or atypical genitalia(n=17). Sinnecker score ≥3 (suggesting antenatal hCG inaction) was seen in 80% (56/70), and hCG-stimulated testosterone was low (<1.1 ng/ml) in 77.4% (24/31), whereas puberty/postpubertal age, high LH (97.6%, 41/42) and low (<1.0 ng/ml) basal testosterone (94.9%, 37/39) was observed in most. FSH was elevated in 21/51 of these patients. Variants with <10% receptor function were exclusively seen in cohorts with Sinnecker 4/5 (10/15 vs. 0/5, p=0.033). 46,XX patients (n=18) presented with oligo/amenorrhea and/or anovulatory infertility and had polycystic ovaries (7/9) with median LH of 10 IU/L (1.2-38). CONCLUSION: In summary, this study comprehensively characterizes LHCGR variants, revealing genotype-phenotype correlations and informing clinical management of LCH. In 46,XY LCH patients, pubertal LH inaction is uniform with variable severity of antenatal hCG inaction. Few mutant LHCGR have differential action for LH and hCG.

Genotype and Phenotype of 21-Hydroxylase Deficiency: A Single Center Experience from Western India.

OBJECTIVE: To describe the genotype-phenotype characteristics of patients with 21-hydroxylase deficiency from western India and ascertain the prevalence of various phenotypes of 21-hydroxylase deficiency. METHODS: Patients with 21-hydroxylase deficiency, diagnosed clinically and biochemically, were prospectively enrolled and classified into salt wasting (SW), simple virilizing (SV), and non-classic (NC) phenotypes and were subjected to genetic testing of CYP21A2 by targeted sequencing and multiplex ligation-dependent probe amplification (MLPA). RESULTS: Eighty (64; 46, XX) probands with 21-hydroxylase deficiency were analyzed. 41 had SW, 34 had SV, and 5 had NC phenotype. Disease-causing mutations were identified in 158/160 alleles. The common mutations were Deletions/Large Gene Conversions (Del/LGC, 25.6%), p.293-13A/C>G (22.5%), and p.Ile173Asn(18.75%). Exon 6 cluster mutations (Ile236Asn, Val237Glu, Met238Lys) and p.Val282Leu were absent. c.-113G>A+p.Pro31Leu (6.87%) and p.Phe405Ser (2.5%) were rare recurrent mutations with a possible founder effect. Two novel variants (Exon 1, p.Leu49Arg, Exon 8, p.Leu362Ter) were identified and were estimated to have low enzyme activity (<2%). CONCLUSION: Del/LGC were the most common mutations identified. The c.-113G>A+p.Pro31Leu and p.Phe405Ser were recurrent variants with possible founder effect. This study also reiterates the low prevalence of NC CAH in Indian cohorts.

Steroidogenic acute regulatory protein (STAR) deficiency: Our experience and systematic review for phenotype-genotype correlation.

OBJECTIVE: Lipoid congenital adrenal hyperplasia (LCAH) is caused by mutations in STAR. A systematic review of phenotype-genotype correlation and data on testicular histology in LCAH patients is unavailable. We aim to describe our experience and provide phenotype-genotype correlation. DESIGN, PATIENTS AND MEASUREMENTS: Retrospective review of three genetically proven LCAH patients from our centre and per-patient data analysis from a systematic review of 292 probands. The phenotypic subgroups of 46,XY were Group A (typical female genitalia), Group B (atypical genitalia) and Group C (typical male genitalia). RESULTS: We report three new LCAH probands from India, all diagnosed post-infancy with preserved gonadal function and one novel variant. The systematic review reports 46,XY to 46,XX LCAH ratio of 1.1 (155:140). Patients with 46,XY LCAH in Group A were diagnosed in infancy (116/117) and had higher mineralocorticoid involvement than Group C (96.4% vs. 75%, p = 0.035), whereas Group C had preserved gonadal function. Hyperplastic adrenals are noted in ~60% of LCAH diagnosed with primary adrenal insufficiency in infancy. There was no report of gonadal germ cell cancer and rare reports of germ cell neoplasia in situ in adolescents, especially with intraabdominal gonads. Two-thirds of LCAH probands were East-Asian and 11/16 regional recurrent variants were from East Asia. There was minimal overlap between variants in Groups A (n = 55), B (n = 9) and C (n = 8). All nonsense and frameshift and most of the splice-site variants and deletion/insertions were present in Group A. CONCLUSIONS: We report three new cases of LCAH from India. We propose a phenotype-derived genotypic classification of reported STAR variants in 46,XY LCAH.