Bloom's syndrome: a probable new case with cytogenetic findings.

A 19-year-old Jordanian girl, born to first-cousin parents, has most features of Bloom's syndrome but is tall and has secondary amenorrhoea. Blood and skin cultures revealed a normal diploid female complement but about one-quarter of the cells show chromosome or chromatid gaps, breaks and rearrangements. These abnormalities were localized after trypsin banding and having been found non-randomly distributed along the chromosomes.