Occurrence of the ACP01 allele in Czechoslovakia.

During a paternity test an unexpected type of red cell acid phosphatase isozyme (ACP1) was found in one family. The mother was of type A and type B was diagnosed in the son. The whole family was then subjected to ACP1 phenotyping and to the enzyme assay. Five members of the family were found to have unexpected types of ACP1 isozymes. The average activity was approx. 50% of normal values. It is presumed that a silent ACP01 allele was found in the family investigated and that the grandfather was its first carrier.