On the genetic polymorphism of the serum alpha-amylase in the population of the south western Bulgaria (second communication).

INTRODUCTION: The paper presents data on population distribution of individual phenotypes and gene frequencies of alpha-amylase in random serum samples from the population of the South-Western regions of Bulgaria.

MATERIAL AND METHODS: We studied 1939 individuals of both sexes aged between 18 and 45 years from the South-Western regions of Bulgaria. They were clinically healthy and without kinship ties. The blood was obtained by venous puncture. The amylase phenotypes were established by horizontal electrophoresis of blood serum on agar gel (1%) after the J. Kompf's method with some modification made in our laboratory.

RESULTS: In the Bulgarian population of the South-Western regions of Bulgaria the most frequent alpha-amylase phenotype is Amy1A Amy2A--1603 (82.67) followed by AmylA Amy2A2B--162 (8.35%); Amy1 A1 B Amy2 A--92 (4.74%); AmylA1B Amy2A2B--58 (2.99%); AmylA Amy2B--17 (0.88%); Amy1c Amy2A--5 (0.26%); and Amy1c Amy2A2B--2 (0.11%). The revealed genetic frequencies are as follows: 1a = 0.9577, 1b = 0.0398, 1 degrees = 0.0025 and 2a = 0.9340 and 2b = 0.0660.

CONCLUSIONS: The difference between the observed theoretically expected types of amylase is not significant so the population studied is in genetic balance regarding the enzyme system. This population does not differ significantly from other populations in gene frequency. A tendency of West-Eastern geographical distribution is evident. Allele frequencies of 1a and 2a tend to increase in that direction. Isoenzyme frequencies in the studied Bulgarian population do not differ significantly from those of the European populations.