Chromosome analysis of uncultured amniocytes by comparative genomic hybridization in early amniocentesis.

OBJECTIVE: To study chromosome analysis by comparative genomic hybridization (CGH) compared with the conventional technique in early amniocentesis. MATERIAL AND METHOD: Cross-sectional descriptive study design was performed in 32 singleton pregnant women with gestational age between 12-15 weeks. Transabdominal amniocentesis was carried out under ultrasound guidance. The amniotic fluid samples were simultaneously investigated using CGH and the conventional cytogenetics study as a gold standard. RESULTS: Amniocentesis were done for advanced maternal age in all cases. The mean maternal age was 35.8 years (35-42 years). The mean gestational age was 13.7 weeks (12-15 weeks). The chromosome analysis by CGH technique of uncultured amniocyte showed 17 normal female chromosomes (53.1%) and 15 normal male chromosomes (46.9%). This finding was the same as the conventional cytogenetics method. The mean duration of the CGH method was 6 days and that of the conventional cytogenetics method was 13.7 days (10-23 days). CONCLUSION: The CGH technique is a reliable technique for a rapid prenatal diagnosis of chromosome study in early gestation.

Monosomy 7 in patients with aplastic anemia and paroxysmal nocturnal hemoglobinuria with evolution into acute myeloid leukemia.

We report two cases of Thai patients with aplastic anemia/paroxysmal nocturnal hemoglobinuria (AA/PNH) who subsequently developed acute myeloid leukemia (AML) at their terminal phase. Monosomy 7 was demonstrated upon karyotypic analysis of bone marrow in both cases at the time leukemia developed The first patient was a 25-year-old man diagnosed with AA at age 14, recovered from AA at age 15, developed PNH at age 21 and turned into AML at age 25. The second patient was a 27-year-old man diagnosed with PNH at age 22, developed severe AA at age 25 and turned into AML at age 27. This latter patient received anti-lymphocyte globulin when he developed severe AA but did not respond well whereas the first patient fully recovered from AA with anabolic hormone treatment. Time to diagnosis of AML in the patient who received immunosuppressive therapy was strikingly shorter than that who received conventional androgen therapy (2 years vs 11 years after AA, respectively). The presence of monosomy 7 in leukemic cells of both patients emphasizes its central role in the development of AML from AA/PNH. However, other factors such as choice of AA/PNH therapy and patients response may modulate the time to emergence of monosomy 7-carrying AML clone and frank leukemia. Further studies into the biologic and genetic mechanisms involved in the development of leukemic clone arising from AA/PNH should be explored.