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AbstractThe genetic polymorphism at apo E locus has been determined among the Kshatriya (n=182) and the Mala (n=38) populations from Andhra Pradesh, India. No significant difference was found in genotype frequencies between the two populations. The sample of the two populations were pooled and called as the Indian sample. The gene frequencies for apo ε2, ε3 and ε4 alleles were 0.0500, 0.8636 and 0.0864, respectively. The allele frequencies of the Indian sample were compared with other Asian populations using χ2test and cluster analysis. The Indian sample differs significantly with most of the Chinese populations and shows similarities with Japanese populations and the Indian sample clusters with Japanese populations.

Elevated levels of lipoprotein(a) [Lp(a)] are associated with increased risk for coronary heart disease (CHD). However, racial differences in both Lp(a) levels and their associated CHD risk are observed, with African Americans having, on average, higher Lp(a) levels than US whites but not the expected increase in CHD risk. We determined Lp(a) levels and their correlates in a large cohort (n = 2379) of black and white girls, ages 9 to 10 years, at the baseline visit of a longitudinal study of obesity development, the National Heart, Lung, and Blood Institute Growth and Health Study. Lp(a) levels were available for 1269 girls. The median Lp(a) level in black girls was over 3-fold higher than that in white girls. Associations were examined between Lp(a) levels and low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, apolipoprotein B, triglycerides, adiposity, pubertal maturation stage, body fat patterning (triceps/truncal skinfold ratio), and dietary fat (Keys' score). In black girls multiple regression analysis identified LDL-C (P < .001) and adiposity (P = .08) as predictors of Lp(a) levels. In white girls only LDL-C (P = .02) was associated with Lp(a). In conclusion, the level of Lp(a) was significantly higher in black girls. Our study also revealed a racial difference in correlates of Lp(a), such as LDL-C and adiposity. Whether this racial difference is due to an underlying biologic difference or is merely a reflection of a greater statistical power to detect a relationship with the level, which was 2.5-fold higher in black girls than in white girls, needs further investigation. (J Pediatr 1999;135:169-76)

The gene for red blood cell (RBC) catalase has recently been mapped to 11p13, and a gene dosage effect has been demonstrated for individuals with triplication or deletion of that region. Deletion of the 11pl3 band has also been associated with aniridia, with and without Wilms’ tumor. We studied the RBC catalase levels in individuals without detectable chromosomal abnormalities but with aniridia, Wilms’ tumor, and the combination of aniridia and Wilms’ tumor, to determine whether catalase levels might provide evidence for a sub-microscopic chromosomal deletion in the 11p13 region. All karyotypically normal patients were found to have normal catalase levels.

Starch gel electrophoresis of Harris’ hawk muscle samples revealed an unusual association of enzyme phenotypes and sex: all females were heterozygous and all males were homozygous. Enzyme activities were not significantly different between sexes. Since birds are characterized by female heterogamety (ZZ males, ZW females), these results are interpreted as suggesting sex linkage with the expression of both Z- and W-linked alleles.

Using a cDNA for glycophorin A (MN), we screened 10 unrelated Caucasians using 22 restriction enzymes for RFLPs. A common StulRFLP was identified and shown to be in marked linkage disequilibrium with both the MN and Ss blood-group antigens in a larger group of unrelated Caucasians. This provides a DNA marker for a locus that has been of major importance in genetic and population studies. The demonstrated disequilibrium will prove useful in localizing the gene for glycophorin B and in studies of genetic and physical distances on human chromosomes.

A survey of genetic variation in urban populations of Aedes aegypti was conducted using starch gel electrophoresis. Ten enzyme loci were examined, 4 of which were found to be polymorphic (Hk, Mdh, Pgm, Pgi). The remaining loci were monomorphic (Aid, Ao, Fum, a-Gpd, Me, 6-Pgd). The expected heterozygosity of the total population (H?) was 9.7%. When the expected total heterozygosity was partitioned, intrapopulation variation accounted for 9.3%; interpopulation variation contributed the remaining 0.4%. The results suggest that the Ae. aegypti population in the Houston area is not genetically subdivided.