ABSTRACT
AIM: The aim of the study was to ascertain some epidemiological factors such as sex and consanguinity that may be associated with cleft lip with or without cleft palate (CL +/- CP) in Kuwait as well as to conduct genetic segregation analysis of these families. SETTING AND SAMPLE POPULATION: A total of 113 families ascertained through 121 CL +/- CP and CP surgical probands in Kuwait. The frequencies of cleft types and the epidemiological variables were calculated using SPSS version 5.0 software. Chi-square for goodness-of-fit test was used to test the significance of the associated epidemiological variables to facial clefts. Genetic segregation analysis was performed on 76 families with extended pedigrees and included only those with non-syndromic CL +/- CP (NS CL +/- CP). Major locus segregation analysis was used to fit models to the observed family patterns under Class A regressive models as implemented by REGD routine in S.A.G.E. release 4.0. A test for heterogeneity was also conducted to complete data set in addition to two subsets: Arabs and nomads. RESULTS: Of the 121 patients, 34(28.1%) had CP, 30(24.8%) had CL and 57 (47.1%) had CL + CP. The male to female ratio was 0.89 for CP, 1.14 for CL, 1.35 for CL + CP and 1.2 for all the clefts. The percentage of consanguineous families among those with a positive family history (60%) was not significantly different from that of the general population (54.3%), whereas for all the families with clefts the percent consanguineous was significantly lower (38%). No evidence of heterogeneity in the results between the Arab and nomad subsets was observed. The results for the major locus segregation analysis were inconclusive. CONCLUSION: No definite association was observed between consanguinity and the occurrence of facial clefts in Kuwait. General transmission models in the full data set showed no evidence of heterogeneity in the results between the Arab and nomad subsets.
Subject(s)
Cleft Lip/epidemiology , Cleft Palate/epidemiology , Adolescent , Adult , Arabs/statistics & numerical data , Chi-Square Distribution , Child , Child, Preschool , Chromosome Mapping , Chromosome Segregation , Cleft Lip/genetics , Cleft Palate/genetics , Consanguinity , Ethnicity/statistics & numerical data , Female , Humans , Infant , Infant, Newborn , Kuwait/epidemiology , Male , Molecular Epidemiology , Pedigree , Regression Analysis , Sex Factors , Transients and Migrants/statistics & numerical dataABSTRACT
Available data indicate structure activity relationships in toxicity and carcinogenecity of aflatoxins in the order of B1 greater than G1 greater than G2 greater than B2. This set of tools is useful for investigations in experimental chemical mutagenesis. The present study is the second in a series concerning the activity of this group of aflatoxins on human chromosomes, using the techniques of Geimsa banding and sister chromatid exchanges. The results showed that aflatoxin G1 is a mutagenic agent to human chromosomes. The distribution of breaks on individual chromosomes according to relative length was nonrandom. Chromosomes 1, 2, 3, 4, and 5, the largest chromosomes, have more breaks, whereas chromosomes 19, 20, 21, and 22, the smallest chromosomes, have less than the expected number of breaks. Comparing these results with that of aflatoxin B1, we found that (1) the mutagenic activity of B1 on human chromosomes is higher than that of G1, and (2) although chromosomes 2, 11, 19, and 20 were the most affected by aflatoxin B1, chromosomes 1, 2, 3, 4, and 5 were the most affected by aflatoxin G1. This result indicates structure activity relationships in mutagenecity that are in agreement with those of the toxicity and carcinogenecity of aflatoxins B1 and G1.
