On the population genetics of phenylketonuria in the G.D.R.

By means of the analysis of the geographical distribution of the birth-places of cases with phenylketonuria, who were detected in a nation-wide screening for phenylketonuria by the Guthrie test during a period of more than 5 years, 3 areas with a remarkably different frequency can be recognized: a) in the districts of Cottbus, Leipzig, Halle and Frankfort the frequency of the phenylketonuria is amounting to 1:6275, of the phenylketonuria-gene to 0.0126 and of the heterozygotes to 2.49%; b) in the remaining districts with the exception of two districts the frequency is significantly lower (1:11272, 0.0094, 1.86%); c) in the districts of Karl-Marx-Stadt and Neubrandenburg this metabolic disease is relatively rare (1:14769, 0.0082, 1.63%). In regions with a high frequency of the phenylketonuria the permanent mild hyperphenylalaninaemia is also twice more frequent than in the remaining country.