Genetic aspects of lactase persistence in different ethnic groups

Abstract

Aim. The aim of this study was evaluation of the genetic aspects of lactase persistence (LP) in persons from different ethnic groups. Methods. Genealogical and medical information was collected about Ukrainian, Indian, Nigerian, Israel, Egypt, Palestine, Turkey, Jordan students (n=361) and their first degree relatives (n=413). Statistical analysis was carried out by Shapiro-Wilk test, χ2, Spearman correlation. Results. The phenotype of LP was found in 69.9 % of Ukrainians, lactose intolerance - in 7.2 %. The highest LP is observed in 95.2 % of Nigerians, the lowest - Palestinians, 51.9 %. Analysis in all ethnic groups showed that the number of LP people is less among parents than among students (r = - 0.529, p <0.05). The LP score is 72.7 - 95.2 % among Nigerian, Israeli, Egyptian, Turkish, Indian students, and 60 - 76.5 % among their parents. The LP phenotype is 50 – 68.8 % and 53.9 – 70.9 % among Ukrainian, Palestinian Jordanian students and their parents. It is likely that adult-type hypolactasia may appear after 20 years and older, indicating a high degree of heterozygosity. The highest number of persons with first exogamy degree is 82.6-85.5 % among Turks, Palestinians, Egyptians and the lowest value of LP phenotype is observed in these groups - 51.9 - 72.3 %, (r = – 0.786, p<0.05). A positive correlation is determined between the traits of hypolactasia and first degree of parents exogamy (r = 0.905, p<0.05). The changes in metabolic status with age could be a predictor for multifactorial pathology. Conclusions. Adult hypolactasia is an age-dependent trait. Relations between the parameters of LP and the origin were established.
 Keywords: lactase persistence, lactose intolerance, exogamy, genotypes.