RESUMEN
Thirty sib-pairs were ascertained through unrelated lepromatous probands. They consisted of 22 healthy individuals and 8 leprosy patients. The Mitsuda reactions of all sibs were evaluated both macroscopically and histologically, and high molecular weight genomic DNA was extracted from the white blood cells of all sib-pairs. Three DNA polymorphisms identified by polymerase chain reaction (274C/T, D543N, 1729 + 55del4) were used as chromosome markers at the NRAMP1 locus. Sib-pair comparisons did not disclose any sign of close linkage between the Mitsuda reaction and the genetic markers.
Asunto(s)
Proteínas de Transporte de Catión/genética , Ligamiento Genético/genética , Lepromina/administración & dosificación , Lepra/genética , Mycobacterium leprae/inmunología , Adulto , Predisposición Genética a la Enfermedad , Humanos , Lepra/inmunología , Persona de Mediana Edad , Núcleo FamiliarRESUMEN
This study comprised 544 nuclear families with 2,925 individuals tested for the Mitsuda reaction, from the Campinas region in Brazil. Segregation analyses suggest the segregation of a major gene (chi 2(1) = 0.07 - 0.07 = 0, p = 1), by failing to reject the hypothesis of Mendelian transmission and by rejecting the hypothesis of nontransmission of a major gene (chi 2(3) = 0.07 - 0.0 = 0.07, p > 0.99; chi 2(2) = 198.28 - 0.0 = 198.28, p < 0.0001).
Asunto(s)
Enfermedades Genéticas Congénitas/genética , Lepra/genética , Modelos Genéticos , Humanos , FenotipoRESUMEN
Data on leprosy patients have been obtained from the Dispensary of Leprosy of Campinas, São Paulo, where records on practically all cases of leprosy in the Campinas area during the period 1960-70 are filed. The whole sample comprises 10,886 individuals, distributed among 1,568 families. Complex segregation analysis was utilized to determine the nature of the genetic factors that may operate on leprosy and its subtypes. The results suggest the presence of a recessive major gene controlling susceptibility to leprosy per se, with frequency of approximately .05, although there are deviations from the expected Mendelian segregation proportions. Possible etiologic heterogeneity was examined by considering two subtypes separately: for lepromatous leprosy and tuberculoid leprosy there are suggestions for a segregating major effect; however, Mendelian transmission could not be demonstrated in either case. Therefore, there is no evidence to suggest unique genetic determinants for leprosy subtypes.
Asunto(s)
Lepra/epidemiología , Lepra/genética , Adolescente , Adulto , Brasil/epidemiología , Niño , Preescolar , Femenino , Genes Recesivos/genética , Predisposición Genética a la Enfermedad , Humanos , Lactante , Recién Nacido , Lepra/clasificación , Masculino , Meiosis , Persona de Mediana Edad , Morbilidad , Fenotipo , Prevalencia , Factores de RiesgoRESUMEN
The level of dapsone in the blood 4 and 6 h after the ingestion of the 7th daily dose of 100 mg of the drug was investigated in 36 adult males with leprosy who had normal renal function and were free of diarrhoea and emesis. The bimodal distribution of the dapsone levels at 6 h was shown by multiple regression analysis to be due to a negative correlation between this trait and the haematocrit value. Among the patients with high dapsone blood levels, 81.8% presented haematocrit values under 36%, whereas only 20% of those with low levels showed low haematocrit values. Partial regression coefficients, calculated for the dapsone level on the age, weight of the patient, estimated number of years since the onset of leprosy, number of years under sulfone treatment, and blood levels of haemoglobin, albumin, and globulins, did not show statistical significance.