[The cytogenetics of premature ovarian failure]

Premature ovarian failure is defined as the occurrence of menopause before the age of 40 years. Etiology has been related to genetic, autoimmune or infectious factors, resistance to gonadotropins and others. Forty-seven patients with this diagnosis were referred for cytogenetic analysis. Sixty-eight percent of the cases had a normal karyotype. In 10.7% there was one 45,X cell and they were catalogued as normal. In 15% of the patients there was a mosaicism with normal cell lines and additional 45,X, 47,XXXX and 48,XXXX ones. Two women had a chromosomal constitution 47,XXX. In one 22-year old patient there was a reciprocal balanced translocation 46,X t(X; 18) (q21.2;q22). The presence of different cell lines, including 45,X cells, could explain an accelerated loss of gametes in the ovary. In women with 47,XXX karyotype, fertility problems and premature menopause have been described. The study of the balanced X-autosome translocation with DNA technics could allow to find the molecular basis of the ovarian failure, permitting the direct search of the gene involved at the site of disruption.