[Genetic morphologic lethal syndrome. Nosologic classification].

A boy with Down syndrome who developed myelodysplastic syndrome after regression of transient abnormal myelopoiesis (TAM) is described. His blast cells in TAM had other chromosome abnormalities in addition to trisomy 21;50,XY,+21c,+12,+14,+21. Serial chromosome analysis in follow-up showed abnormal clones involving monosomy 7. Myelodysplastic syndrome was diagnosed. Because two clones had different karyotypes, they might have derived from different clones.

Chromosome Aberrations↗

PubMed1998

Correlation of cytogenetic abnormalities with the outcome of patients with uveal melanoma.

BACKGROUND: Cytogenetic investigations of choroid and ciliary body melanomas have revealed that the majority of cases are characterized by recurrent clonal abnormalities involving chromosomes 3, 6, and 8. The authors sought to determine whether these abnormalities were associated with outcome. METHODS: Fifty-four patients who underwent enucleation for untreated uveal melanoma between 1988 and 1996 were subjected to complete cytogenetic analysis. The most recent follow-up data from the time of enucleation was obtained. Patient outcomes were divided into two groups: 1) alive with metastases or dead of disease, and 2) alive without known metastases or dead of other causes. The relative risk (RR) and 95% confidence interval (CI) of a poor outcome were calculated for each chromosomal abnormality and clinical characteristic. RESULTS: Patients were followed for a median of 38 months. No patients were lost to follow-up. Abnormalities of chromosomes 3 and 8 were associated with a poor prognosis, but only when these two chromosomal abnormalities were present together (RR = 4.1, 95% CI = 1.7-9.9). The presence of a chromosome 6 abnormality was predictive of a good outcome (RR = 0.2, 95% CI = 0.1-0.8), even in the presence of chromosome 3 and 8 abnormalities. The only clinical factor associated with a poor outcome was the presence of extrascleral extension. CONCLUSIONS: In this group of patients with large posterior uveal melanomas, the concurrent presence of cytogenetic abnormalities of chromosomes 3 and 8 was associated with a poor outcome. An abnormality of chromosome 6 appeared to have a protective effect. These data suggest that cytogenetic analysis may provide prognostic information on patients with uveal melanoma and that further investigation of the contributions of these chromosomal aberrations to disease progression is warranted.

Chromosome Aberrations↗

PubMed1998

The Allium cepa chromosome aberration test reliably measures genotoxicity of soils of inhabited areas in the Ukraine contaminated by the Chernobyl accident.

The accident on the Chernobyl Nuclear Power Plant reactor IV in April 1986 led to the release of an enormous amount of radioactive material into the biosphere and to the formation of a complex pattern of nuclear contamination over a large area. As a consequence more than 5 million km2 of the soil in the Ukraine became contaminated with more than 1 Ci/km2 [1,2]. An assessment of the genetic consequences of the nuclear pollution is one of the most important problems. We applied the Allium cepa test to estimate the impact on plant chromosomes of nuclear pollution in the inhabited zones of the Ukraine. We tested soil from the obligatory resettlement zone (zone 2), where the mean density of pollution is 15-40 Ci/km2; zones of enhanced radiological control-zone 3, 5-15 Ci/km2 and zone 4, 1-5 Ci/km2. We found a dose-dependent increase in the fraction of aberrant mitoses from control values of 1.6 +/- 0.9% up to 23.8 +/- 5.0%, and a corresponding monotonous decrease of the mitotic index from 49.4 +/- 4.8% to a limiting value of 22.5 +/- 4.0% at pollution levels exceeding 35 Ci/km2 (activity of the soil samples exceeding 6000 Bq/kg, respectively). We observed a strong, significant correlation of 137Cs activity of soil samples with the percentage of chromosomal abnormalities, r = 0.97 (P < 0.05), and with the mitotic index, r = -0.93 (P < 0.05), in the roots of A. cepa, respectively. The results showed high toxicity and genotoxicity of radioactively polluted soils and confirmed the efficiency of the A. cepa test as a quick and inexpensive biological test for ecological and genetic risk assessment in the 'Chernobyl' zones.

Chromosome Aberrations↗