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.