Polycystic Ovary Syndrome Physiologic Pathways Implicated Through Clustering of Genetic Loci.

CONTEXT: Polycystic ovary syndrome (PCOS) is a heterogeneous disorder, with disease loci identified from genome-wide association studies (GWAS) having largely unknown relationships to disease pathogenesis. OBJECTIVE: This work aimed to group PCOS GWAS loci into genetic clusters associated with disease pathophysiology. METHODS: Cluster analysis was performed for 60 PCOS-associated genetic variants and 49 traits using GWAS summary statistics. Cluster-specific PCOS partitioned polygenic scores (pPS) were generated and tested for association with clinical phenotypes in the Mass General Brigham Biobank (MGBB, N = 62 252). Associations with clinical outcomes (type 2 diabetes [T2D], coronary artery disease [CAD], and female reproductive traits) were assessed using both GWAS-based pPS (DIAMANTE, N = 898,130, CARDIOGRAM/UKBB, N = 547 261) and individual-level pPS in MGBB. RESULTS: Four PCOS genetic clusters were identified with top loci indicated as following: (i) cluster 1/obesity/insulin resistance (FTO); (ii) cluster 2/hormonal/menstrual cycle changes (FSHB); (iii) cluster 3/blood markers/inflammation (ATXN2/SH2B3); (iv) cluster 4/metabolic changes (MAF, SLC38A11). Cluster pPS were associated with distinct clinical traits: Cluster 1 with increased body mass index (P = 6.6 × 10-29); cluster 2 with increased age of menarche (P = 1.5 × 10-4); cluster 3 with multiple decreased blood markers, including mean platelet volume (P = 3.1 ×10-5); and cluster 4 with increased alkaline phosphatase (P = .007). PCOS genetic clusters GWAS-pPSs were also associated with disease outcomes: cluster 1 pPS with increased T2D (odds ratio [OR] 1.07; P = 7.3 × 10-50), with replication in MGBB all participants (OR 1.09, P = 2.7 × 10-7) and females only (OR 1.11, 4.8 × 10-5). CONCLUSION: Distinct genetic backgrounds in individuals with PCOS may underlie clinical heterogeneity and disease outcomes.

A functional spectrum of PROKR2 mutations identified in isolated hypogonadotropic hypogonadism.

Isolated hypogonadotropic hypogonadism (IHH) is a rare disease with hypogonadism and infertility caused by the defects in embryonic migration of hypothalamic gonadotropin-releasing hormone (GnRH) neurons, hypothalamic GnRH secretion or GnRH signal transduction. PROKR2 gene, encoding a G-protein coupled receptor PROKR2, is one of the most frequently mutated genes identified in IHH patients. However, the functional consequences of several PROKR2 mutants remain elusive. In this study, we systematically analyzed the Gαq, Gαs and ERK1/2 signaling of 23 IHH-associated PROKR2 mutations which are yet to be functionally characterized. We demonstrate that blockage of Gαq, instead of MAPK/ERK pathway, inhibited PROK2-induced migration of PROKR2-expressing cells, implying that PROKR2-related IHH results primarily due to Gαq signaling pathway disruption. Combined with previous reports, we categorized a total of 63 IHH-associated PROKR2 mutations into four distinct groups according Gαq pathway functionality: (i) neutral (N, >80% activity); (ii) low pathogenicity (L, 50-80% activity); (iii) medium pathogenicity (M, 20-50% activity) and (iv) high pathogenicity (H, <20% activity). We further compared the cell-based functional results with in silico mutational prediction programs. Our results indicated that while Sorting Intolerant from Tolerant predictions were accurate for transmembrane region mutations, mutations localized in the intracellular and extracellular domains were accurately predicted by the Combined Annotation Dependent Depletion prediction tool. Our results thus provide a functional database that can be used to guide diagnosis and appropriate genetic counseling in IHH patients with PROKR2 mutations.

Reproductive Phenotypes and Genotypes in Men With IHH.

CONTEXT: Isolated hypogonadotropic hypogonadism (IHH) is phenotypically and genetically heterogeneous. OBJECTIVE: This work aimed to determine the correlation between genotypic severity with pubertal and neuroendocrine phenotypes in IHH men. METHODS: A retrospective study was conducted (1980-2020) examining olfaction (Kallmann syndrome [KS] vs normosmic IHH [nHH]), baseline testicular volume (absent vs partial puberty), neuroendocrine profiling (pulsatile vs apulsatile luteinizing hormone [LH] secretion), and genetic variants in 62 IHH-associated genes through exome sequencing (ES). RESULTS: In total, 242 men (KS: n = 131 [54%], nHH: n = 111 [46%]) were included. Men with absent puberty had significantly lower gonadotropin levels (P < .001) and were more likely to have undetectable LH (P < .001). Logistic regression showed partial puberty as a statistically significant predictor of pulsatile LH secretion (R2 = 0.71, P < .001, OR: 10.8; 95% CI, 3.6-38.6). Serum LH of 2.10 IU/L had a 95% true positive rate for predicting LH pulsatility. Genetic analyses in 204 of 242 IHH men with ES data available revealed 36 of 204 (18%) men carried protein-truncating variants (PTVs) in 12 IHH genes. Men with absent puberty and apulsatile LH were enriched for oligogenic PTVs (P < .001), with variants in ANOS1 being the predominant PTV in this genotype-phenotype association. Men with absent puberty were enriched for ANOS1 PTVs compared to partial puberty counterparts (P = .002). PTVs in other IHH genes imparted more variable reproductive phenotypic severity. CONCLUSION: Partial puberty and LH greater than or equal to 2.10 IU/L are proxies for pulsatile LH secretion. ANOS1 PTVs confer severe reproductive phenotypes. Variable phenotypic severity in the face of severe genetic variants in other IHH genes point to significant neuroendocrine plasticity of the HPG axis in IHH men.

Prevalence and Phenotypic Effects of Copy Number Variants in Isolated Hypogonadotropic Hypogonadism.

CONTEXT: The genetic architecture of isolated hypogonadotropic hypogonadism (IHH) has not been completely defined. OBJECTIVE: To determine the role of copy number variants (CNVs) in IHH pathogenicity and define their phenotypic spectrum. METHODS: Exome sequencing (ES) data in IHH probands (n = 1394) (Kallmann syndrome [IHH with anosmia; KS], n = 706; normosmic IHH [nIHH], n = 688) and family members (n = 1092) at the Reproductive Endocrine Unit and the Center for Genomic Medicine of Massachusetts General Hospital were analyzed for CNVs and single nucleotide variants (SNVs)/indels in 62 known IHH genes. IHH subjects without SNVs/indels in known genes were considered "unsolved." Phenotypes associated with CNVs were evaluated through review of patient medical records. A total of 29 CNVs in 13 genes were detected (overall IHH cohort prevalence: ~2%). Almost all (28/29) CNVs occurred in unsolved IHH cases. While some genes (eg, ANOS1 and FGFR1) frequently harbor both CNVs and SNVs/indels, the mutational spectrum of others (eg, CHD7) was restricted to SNVs/indels. Syndromic phenotypes were seen in 83% and 63% of IHH subjects with multigenic and single gene CNVs, respectively. CONCLUSION: CNVs in known genes contribute to ~2% of IHH pathogenesis. Predictably, multigenic contiguous CNVs resulted in syndromic phenotypes. Syndromic phenotypes resulting from single gene CNVs validate pleiotropy of some IHH genes. Genome sequencing approaches are now needed to identify novel genes and/or other elusive variants (eg, noncoding/complex structural variants) that may explain the remaining missing etiology of IHH.

Impaired Sexual Function in Young Women With PCOS: The Detrimental Effect of Anovulation.

BACKGROUND: Even though polycystic ovary syndrome (PCOS) is a common reproductive disorder affecting young women, its impact on their sexual health is not well known. AIM: To examine the different aspects of female sexuality in young women with PCOS and attempt to associate hormonal changes and ovulatory status with their sexual function. METHODS: Anthropometric characteristics, hormonal levels and sexual function based on the Female Sexual Function Index (FSFI) questionnaire were assessed in 76 young women with PCOS and 133 matched controls. OUTCOMES: Sexual function is significantly impaired in young women with PCOS. RESULTS: Women with PCOS demonstrated lower scores than controls in arousal (5.04 ± 1.19 vs 4.48 ± 1.44, P < .001), lubrication (5.29 ± 1.17 vs 4.69 ± 1.54, P < .001), orgasm (4.78 ± 1.40 vs 4.11 ± 1.61, P = .001), satisfaction (5.22 ± 1.10 vs 4.78 ± 1.31, P = .016), and total score of the FSFI (29.51 ± 5.83 vs 26.76 ± 6.81, P < .001), even after correction for BMI. When corrected for total testosterone, the domains of lubrication, satisfaction, and total score of FSFI remained significantly impaired in women with PCOS (P values .037, .024, & .044 respectively). In multivariate logistic regression analysis, after adjusting for the effect of BMI and hormone levels, dysfunction in orgasm, satisfaction and the total FSFI score were still 3-4 times more common in PCOS (adjusted OR [95% CI]: 3.54, P = .020; 2.96, P = .050; 3.87, P = .027). Even though no statistically significant differences were observed between women with ovulatory PCOS and controls, we detected statistically significant differences in all domains of sexual function apart from pain between controls and PCOS women with anovulation (desire P value .04, arousal P value <.001, lubrication P value <.001, orgasm P value .001, satisfaction P value .001 and FSFI total score P value <.001). CLINICAL IMPLICATIONS: Women with PCOS have compromised sexual function, which is independent of their BMI and highly dependent on their ovulatory status. STRENGTHS AND LIMITATIONS: This is the first study in women with PCOS that implicates anovulation as a risk factor for sexual impairment in PCOS. Further studies are needed to elucidate the mechanisms implicated and to examine the effect of PCOS therapy on the patients' sexual function. CONCLUSION: The adverse effect of PCOS status on the female sexual function is independent of BMI and only partially dependent on hormonal changes characterizing the syndrome. Anovulation appears to be the major determinant of sexual impairment among women with PCOS. Mantzou D, Stamou MI, Armeni AK, et al. Impaired Sexual Function in Young Women With PCOS: The Detrimental Effect of Anovulation. J Sex Med 2021;18:1872-1879.

Kallmann syndrome: phenotype and genotype of hypogonadotropic hypogonadism.

Isolated Gonadotropin-Releasing Hormone (GnRH) Deficiency (IGD) IGD is a genetically and clinically heterogeneous disorder. Mutations in many different genes are able to explain ~40% of the causes of IGD, with the rest of cases remaining genetically uncharacterized. While most mutations are inherited in X-linked, autosomal dominant, or autosomal recessive pattern, several IGD genes are shown to interact with each other in an oligogenic manner. In addition, while the genes involved in the pathogenesis of IGD act on either neurodevelopmental or neuroendocrine pathways, a subset of genes are involved in both pathways, acting as "overlap genes". Thus, some IGD genes play the role of the modifier genes or "second hits", providing an explanation for incomplete penetrance and variable expressivity associated with some IGD mutations. The clinical spectrum of IGD includes a variety of disorders including Kallmann Syndrome (KS), i.e. hypogonadotropic hypogonadism with anosmia, and its normosmic variation normosmic idiopathic hypogonadotropic hypogonadism (nIHH), which represent the most severe aspects of the disorder. Apart from these disorders, there are also "milder" and more common reproductive diseases associated with IGD, including hypothalamic amenorrhea (HA), constitutional delay of puberty (CDP) and adult-onset hypogonadotropic hypogonadism (AHH). Interestingly, neurodeveloplmental genes are associated with the KS form of IGD, due to the topographical link between the GnRH neurons and the olfactory placode. On the other hand, neuroendocrine genes are mostly linked to nIHH. However, a great deal of clinical and genetic overlap characterizes the spectrum of the IGD disorders. IGD is also characterized by a wide variety of non-reproductive features, including midline facial defects such as cleft lip and/or palate, renal agenesis, short metacarpals and other bone abnormalities, hearing loss, synkinesia, eye movement abnormalities, poor balance due to cerebellar ataxia, etc. Therefore, genetic screening should be offered in patients with IGD, as it can provide valuable information for genetic counseling and further understanding of IGD.