Haptoglobin subtypes in Berlin, GDR. A simple procedure for haptoglobin purification and subtyping.

Sera were obtained from 1,275 blood donors in Berlin, probands involved in paternity tests, and from 119 families with 235 children; the sera were subtyped by isoelectric focusing, following preparation and reductive molecular cleavage of haptoglobin. In this paper, an uninvolved preparation technique is described for routine testing. Allelic frequencies are: Hp *1F = 0.1471; *1S = 0.2502; *2FF = 0.0020; *2FS = 0.5753; *2SS = 0.0251. Only one deviation from autosomal codominant inheritance was recorded in the family examinations, with illegitimacy considered possible. In the region of Berlin, the changes of ruling out uninvolved individuals in paternity suits have gone up from 18% (conventional technique recording two frequent alleles) to 33% (subtyping).