Cryptic Xp duplication including the SHOX gene in a woman with 46,X, del(X)(q21.31) and premature ovarian failure

BACKGROUND: Premature ovarian failure (POF) is defined as amenorrhoea for > 6 months, occurring before the age of 40, with an FSH serum level in the menopausal range. Although Xq deletions have been known for a long time to be associated with POF, the mechanisms involved in X deletions in order to explain ovarian failure remain unknown. In order to look for potentially cryptic chromosomal imbalance, we used high-resolution genomic analysis to characterize X chromosome deletions associated with POF. METHODS: Three patients with POF presenting terminal Xq deletions detected by conventional cytogenetics were included in the study. Genome wide microarray comparative genomic hybridization (CGH) at a resolution of 1 Mb and fluorescence in situ hybridization (FISH) was performed. RESULTS: Microarray CGH and FISH studies characterized the three deletions as del(X)(q21.2), del(X)(q21.31) and del(X)(q22.33). Microarray CGH showed that the del(X)(q21.31) was also associated with a Xpter duplication including the SHOX gene. In these patients with POF, deletions or duplications of autosomes have been excluded. CONCLUSION: This study is the first one using microarray in patients with POF. It demonstrates that putative X chromosome deletions can be associated with other chromosomal imbalances such as duplications, and therefore illustrates the use of microarray CGH to screen chromosomal abnormalities in patients with POF.