Chromosomic findings in patients with paroxysmal nocturnal hemoglobinuria.

The chromosomes of 14 patients (9 males, 5 females) suffering from paroxysmal nocturnal hemoglobinuria in Merida, Mexico between April 1989 and July 1992 were analyzed. Four of the patients were children (range, 3-15 years old) and 9 were adults (range, 19-62 years old). None of the patients had any evidence of leukemic transformation and 9 of them had antecedent insecticide exposure. In 50%, the clinical presentation was anemia plus hemorrhagic syndrome. Only 1 case had thrombosis. The lapse between the beginning of the disease and the karyotypic analysis was 14.5 months on average (range, 1-172 months). In all cases we found a normal chromosomic complement. In addition, 5 patients had an acentric fragment in only 1 metaphase and one of these had a mar and Cq chromatid break in another metaphase, but neither could be considered as specific chromosomal abnormality for paroxysmal nocturnal hemoglobinuria.