Glutathione S-transferases (GST; E.C.2.5.1.18) were phenotyped by starch gel electrophoresis in post-mortem liver samples from 683 unrelated subjects of both sexes. 305 were Chinese, 185 Indians, 147 Malays and 46 from other racial groups of South-East Asia. GST1 and GST2 were found to be polymorphic in these populations. Additional alleles (GST1*3 and GST2*O) were observed at low frequency in all the ethnic groups. The frequency of GST1*1 was lower and that of GST1*2 was higher in Indians and Malays as compared to Chinese. GST1*0 and GST1*3 frequencies were similar in all these ethnic groups. The gene frequencies of the alleles of the GST2 locus varied significantly in the population studied. GST2*0 frequency was significantly higher in Indians than in Chinese and Malays, while the lowest frequency of GST2*1 was found in the Indians. GST2*2 frequency was higher in the Malays than in Chinese and Indians. GST1 and GST2 phenotype distributions were in agreement with Hardy-Weinberg equilibrium in all the ethnic groups studied. Sex made no significant difference in the phenotype distribution.
1. The vitamin A content of human liver tissue was determined in 363 autopsy samples. The sample comprised a total of 181 subjects dying after accidents and 182 dying from coronary heart disease among Singapore ethnic groups of both sexes. 2. The medium vitamin A reserve was 146 mg/kg in accident victims and 141 mg/kg in those who had died of coronary heart disease. Of all the samples 16% contained less than 40 mg/kg, 45% had 100-300 mg/kg, while 9% contained more than 500 mg/kg liver. 3. Among the accident victims, Indians had the lowest median liver vitamin A reserve (118 mg/kg) compared with that in other ethnic groups (137 mg/kg in Chinese, 191 mg/kg in Malays, 155 mg/kg in Caucasians). 4. The ethnic distribution of vitamin A reserve in coronary deaths was similar to that in accident victims. 5. There was no significant difference between the sexes in hepatic vitamin A reserve. 6. The distribution of vitamin A reserve in all the groups was skewed to the right.