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Background: In premature ovarian failure (POF), cessation of menstruation occurs before the expected age of menopause. Approximately 1% of women are affected. FMR1 premutation was reported to be responsible for up to 3.3%-6.7% of sporadic POF and 13% of familial cases in Caucasians, while the data was absent in Chinese population. Therefore, the impact of FMR1 CGG repeat on ovarian reserve is needed to be investigated in large Chinese cohort., Methods: The number of FMR1 CGG repeat was determined in 379 Han Chinese women with well-defined 46, XX non-syndromic sporadic POF and 402 controls. The age of menopause onset in respect to CGG repeats was further analyzed., Results: The frequency of FMR1 premutation in Han Chinese POF was only 0.5% (2/379), although it was higher than that in matched controls (0%, 0/402), it was much lower than that reported in Caucasian with POF (3.3%-6.7%). The prevalence of intermediate FMR1 (41-54) was not increased significantly in sporadic POF than that in controls (2.9% vs. 1.7%, P = 0.343). However, POF patients more often carried a single additional CGG repeat in a single allele than did fertile women (allele-1: 29.7 vs. 28.8, P<0.001; allele-2: 32.6 vs. 31.5, P < 0.001). POF patients with both alleles of CGG repeats outside (below or above) the normal range (26-34) showed an earlier age of cessation of menses than those with two alleles within normal range (hom-high/high vs. norm: 20.4 ± 4.8 vs. 24.7 ± 6.4, p < 0.01; hom-low/high vs. norm: 18.7 ± 1.7 vs. 24.7 ± 6.4, p < 0.01)., Conclusions: FMR1 premutation seems to be an uncommon explanation for POF in Han Chinese. However, having both alleles with CGG repeats outside the normal range might still adversely affect ovarian aging.

Objective: To determine whether variants in the SOHLH2 gene contribute to human premature ovarian failure (POF) in different ethnicities., Design: Case-control genetic study., Setting: University hospitals., Patient(s): Chinese (364 cases) and Serbian (197 cases) women with nonsyndromic POF and ethnically matched controls., Intervention(s): None., Main Outcome Measure(s): Variation analysis of the SOHLH2 gene., Result(s): Eleven novel heterozygous variants were identified in cohorts of POF but were absent in matched controls. These included the nonsynonymous variants p.Glu79Lys (n = 2 cases), p.Glu105Gly, and p.Thr321Pro, which were found among four Chinese POF cases, and p.Leu120Phe (n = 3 cases) and p.Leu204Phe, which were found among four Serbian women. Protein alignments reveal that p.Glu79Lys and p.Glu105Gly involve amino acids highly conserved among mammals, both of which are predicted to be deleterious. The c.-210G>T found in the Chinese POF cohort lies in the core promoter region, which is enriched with transcription factor binding sites and CpG islands. In the Serbian cohort, the variant most likely to have a deleterious effect is c.530+6T>G, which is predicted to affect RNA splicing and result in nonsense mediated decay of transcripts. The other variants are less likely to be deleterious. Disturbing the expression, transactivation or homo-/ heterodimerization of the SOHLH2 protein could result in ovarian failure. Overall, four of the 11 novel variants seem plausible explanations for POF; the other seven variants are less likely but cannot be categorically excluded., Conclusion(s): Our identification of novel variants in the SOHLH2 gene, in women with POF of both Chinese and Serbian origin, strongly suggests an important role for SOHLH2 in human POF etiology., (Copyright © 2014 American Society for Reproductive Medicine. All rights reserved.)

Background: This retrospective cohort study was to determine the frequency and types of chromosomal abnormalities in Han Chinese women with well-documented premature ovarian failure (POF)., Methods: Karyotype analysis and correlation to phenotypes were performed on 531 Chinese patients with proven POF (FSH > 40 mIU/ml) attending four reproductive centers in China. G-banded metaphase chromosomes were prepared and analyzed, with mosaicism excluded by counting up to 100 cells from lymphocytes., Results: Chromosomal abnormalities were present in 64 of 531 (12.1%) POF cases, of which 32 were X-structural aberrations (7 mosaic): 15 del(Xq), 2 del(Xp), 11 isochromosomes [6 i(Xp); 5 i(Xq)], 1 ring chromosome (mosaic), 1 inversion (mosaic), 1 isodicentric chromosome and 1 complex arrangement. Nine non-mosaic X-autosome translocations were detected, all but 1 involving Xq. Aneuploidy without a structurally abnormal X was found in 19 cases: 7 non-mosaic 45,X, 9 45,X mosaicisms and 3 47,XXX (1 mosaic with 46,XX line). Karyotypic abnormalities were more frequent in patients with primary amenorrhea (15/70, 21.4%) than those with secondary amenorrhea (49/461, 10.6%; P = 0.01). 45,X and 45,X/46,XX mosaicism were the complements most frequently associated with primary amenorrhea (46.7%). Two of the three cases with 46,XY or 45,X/46,XY karyotype presented with 'secondary amenorrhea'. One balanced autosomal Robertsonian translocation was also detected., Conclusions: The overall prevalence of chromosomal abnormalities was 12.1% in this first large scale report of chromosomal aberrations in Chinese women with POF. In one of the largest samples of women with POF reported from any population, the prevalence of X-structural abnormalities, X-autosome translocations and X aneuploidy confirms the essential role X chromosomal abnormalities play in POF.

Premature ovarian failure (POF) is a complex heritable disorder known to be caused by chromosomal abnormalities and to date a limited number of known mutations, often autosomal. We sought to identify additional genetic loci associated with POF by performing the first large-scale genome-wide association study (GWAS). GWAS, using Affymetrix SNP 6.0 chip, was conducted in an initial discovery set of 391 well-documented (follicle-stimulating hormone >40 IU/ml) Chinese Han POF patients, compared with 895 unrelated Chinese female controls. A replication study on the most significant loci was then performed in an independent set of 400 cases and 800 controls. Suggestive significant associations were observed at 8q22.3. Replication of eight single-nucleotide polymorphisms (SNPs) (rs10464815, rs10808365, rs3847152, rs3847153, rs3847154, rs3843552, rs10955242, rs3843555) (P ≤ 3.86 × 10(-6)) was confirmed in verification sets. No specific candidate gene was found in the immediate region of 8q22.3. This GWAS, involving by far the largest sample of POF cases accumulated to date, revealed heretofore unrecognized association between POF and a novel genetic locus or region of unknown nature on 8q22.3. We speculate existence of a long-distance regulatory region that has relevance to the control of ovarian differentiation or oogenesis. Given failure to find association with any of the other autosomal regions known to harbor genes causing ovarian failure, our findings also underscore the likelihood of considerable genetic and etiologic heterogeneity in POF and the need for additional approaches like whole-genome sequencing., (© The Author 2011. Published by Oxford University Press. All rights reserved.)

The newborn ovary homeobox gene (NOBOX) is an oocyte-specific homeobox gene that plays a critical role in early folliculogenesis, thus representing an attractive candidate gene for nonsyndromic ovarian failure. We investigated whether perturbation in the homeodomain region of NOBOX was present in Chinese women with premature ovarian failure (POF). We sequenced 200 Chinese patients with POF, and discovered only two known single nucleotide polymorphisms: in intron 6 (c.1154+11 T>C and c.1155-22 G>A); neither offers plausible explanations for POF. Failing to find causative mutation contrasts with our previous study in a caucasian sample, in which we found plausible homeobox mutation in 1 of 96 POF cases. Mutations in the homeobox domain of NOBOX are not common explanations for POF in Chinese women.

Aim: The purpose of the study was to evaluate the feasibility and reliability of comparative genomic hybridization (CGH) in the detection of genomic imbalances in Chinese malformed fetuses., Methods: Genomic DNA was extracted from umbilical cord blood or fresh amniotic fluid of 9 malformed fetuses and labeled with SpectrumGreen dUTP or SpectrumRed dUTP. A pair of CGH analyses in which the fluorochromes were exchanged was carried out for each sample., Results: Samples from 9 malformed fetuses were analyzed successfully by CGH. Numerical chromosome aberrations were detected in samples from cases 4, 8 and 9, and were verified by fluorochrome-exchanged CGH. Trisomy 21q was detected in case 4, del 2p24-pter and dup 12p13 was detected in case 8, and del 1p33-pter and del 22q11-12 were detected in case 9., Conclusion: CGH is a reliable technique for the detection of genomic imbalances. Fluorochrome-exchanged CGH can reduce inconsistencies in the results caused by deviations in the process of DNA labeling and hybridization, and increase the accuracy and reliability in cases when conventional cytogenetic analysis is unavailable.