RESUMEN
Down syndrome has been linked to premature aging and genomic instability. We examined the frequency of micronucleus (MN) and binucleated cells in the oral mucosa of Down syndrome patients and healthy controls matched by age and gender, addressing the effect of age and family income. Down syndrome individuals had an increased number of MN (14.30 +/- 9.35 vs 4.03 +/- 1.71; P<0.001) and binucleated cells (0.97 +/- 1.3 vs 0.33 +/- 0.66; P<0.05) per 2000 cells. Micronucleus frequency of Down syndrome individuals correlated positively with age (r = 0.437; P = 0.009), and the older (> or =21) Down syndrome age group (30.8 +/- 8.4 years old) had about 2-fold more micronuclei (P < or = 0.05) than did the younger group (<21). Average family income did not correlate with MN frequency in controls (r = -0.948; P = 0.183), but a borderline negative correlation was seen in DS subjects (r = -0.9484; P = 0.0516). Individuals whose average income was ten times minimum wages had about 2-fold less MN than those receiving around minimum wage. We conclude that the buccal MN assay is a useful and minimally invasive method for monitoring genetic damage in humans and could be used as a tool to evaluate age-associated genomic instability in Down syndrome.
Asunto(s)
Factores de Edad , Síndrome de Down/genética , Pruebas de Micronúcleos , Adolescente , Adulto , Estudios de Casos y Controles , Mejilla , Niño , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
From 1986 to 2002, we examined the chromosomal composition of 916 patients attended by two genetic counseling services in the city of Pelotas, in the Brazilian State of Rio Grande do Sul, to determine the genetic causes of their disturbances. Patterns of G-banding using trypsin and Giemsa (GTG) and C-banding using barium and Giemsa (CBG) were studied using phytohemagglutinin M-stimulated lymphocytes cultured from peripheral blood. Among the patients, 110 had Down's syndrome, 7 had Edward's syndrome, 4 had Patau's syndrome, 29 had Turner's syndrome, 5 had Klinefelter's syndrome, and 3 had "cri-du-chat" syndrome. Abnormal chromosomes were observed in 29.3% of the patients. Most of these (56.3%) were numerical abnormalities, with the remaining being structural variants.
Asunto(s)
Aberraciones Cromosómicas , Bandeo Cromosómico/métodos , Trastornos de los Cromosomas/diagnóstico , Asesoramiento Genético , Brasil , Trastornos de los Cromosomas/genética , Femenino , Humanos , Cariotipificación/métodos , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/genética , Masculino , FitohemaglutininasRESUMEN
In this study, the micronuclei test (MNT) was applied in exfoliated cells of buccal mucosa, in order to evaluate the genotoxic risk associated with occupational exposure of mechanics, storage battery renovation workers, and car painters. For each individual, 3000 exfoliated buccal cells were analyzed. There was a significantly higher frequency of micronucleated cells (MNC) in the exposed workers than in controls. Smoking and drinking habits, age, and working time did not represent significant factors in terms of increasing the production of micronuclei (MN), when the control and the exposed groups were compared. These results allowed to conclude that the studied individuals belong to a risk group and should periodically undergo biological monitoring and proper care