RESUMEN
Nonsyndromic cleft lip with or without cleft palate (CL/P) has an incidence of 1.5 per 1,000 live births in Chile, with 1.7 per 1,000 in males and 1.3 per 1,000 in females, which is nearly the same as the level found in Asian populations. The high rate of occurrence of CL/P in Chile is probably due to the presence of Amerindian genes in Chilean populations. Using the computer program PAP, a complex segregation analysis of CL/P was conducted for 67 multigeneration pedigrees from Chile, each ascertained from one affected proband. These pedigrees yielded 162 affected individuals and over 898 family members who were included in the analysis. The most parsimonious model of transmission indicated the presence of an autosomal dominant gene with reduced (20-25%) penetrance.
Asunto(s)
Labio Leporino/genética , Fisura del Paladar/genética , Indígenas Sudamericanos/genética , Población Blanca/genética , Chile/epidemiología , Labio Leporino/epidemiología , Fisura del Paladar/epidemiología , Femenino , Humanos , Funciones de Verosimilitud , Masculino , Meiosis , Modelos Genéticos , Linaje , Factores SexualesRESUMEN
A large earthquake (8-9 on the Richter scale) and a series of aftershocks took place on 2 March 1985 in Santiago, Chile. The characteristics of over 22,000 births registered in three public hospitals in the same year were reviewed. A significant increase in the rate of facial clefts was found; 2.01 per 1000 births in contrast to 1.6 per 1000 births in previous years. The increase was greater in those born in September: 3.8 per 1000 births. This increase in clefting could be related to the effects of stress in mothers induced by the earthquake, and to test this hypothesis 13.5-day-old embryos from two inbred mouse strains, A/Sn and C57BL/10, were subjected to a similar stress using a vibrator cage to imitate the main shock and the first five replicas of the earthquake. The same intensity and duration of shock as in the original earthquake were applied. The results were 19.8% cleft palates in stressed A/Sn mice and no clefting in C57BL/10. This was highly significant in A/Sn mice (chi 2 = 19.9; P < 0.001) but not in C57BL/10. No clefting was found in controls in both strains. A surprising finding was the proportion of resorbed embryos in the stressed groups, which increased from 8.3 to 49.3% in A/Sn and from 5.8 to 48.3% in C57BL/10. It is known that A/Sn mice are genetically sensitive to cleft palate induction by cortisone, while C57BL/10 are not. These findings in mice support the stress hypothesis for the increase in cleft palate observed in humans. The increase in resorbed embryos in both strains also suggests an effect on stress.
Asunto(s)
Labio Leporino/etiología , Fisura del Paladar/etiología , Desastres , Efectos Tardíos de la Exposición Prenatal , Vibración/efectos adversos , Animales , Distribución de Chi-Cuadrado , Chile , Femenino , Humanos , Recién Nacido , Masculino , Ratones , Ratones Endogámicos A , Ratones Endogámicos C57BL , Embarazo , Estrés Fisiológico/fisiopatologíaRESUMEN
We studied the effect of nonsteroid antiinflammatory (Indomethacin, R), in the palate fusion of rat embryos from different strains with variable susceptibility and also the influence of glucocorticoids. Indomethacin inhibits the fusion of the palate process with variable rate depending of the rat strain. In reciprocal inbred we observed that the effect is greater in embryo from susceptible females than from resistant females. This demonstrates that there are a maternal influence in the induction of cleft palate due to Indomethacin.