Cytogenetic analysis of 531 Chinese women with premature ovarian failure

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.