SEGREGATION STUDY OF THE SOLUBLE 39-KD HLA CLASS-I HEAVY-CHAIN

To study the variable expression and inheritance of the 39-kD M(r) for m of sHLA class I molecules, we investigated the plasma of 12 families with 61 members and 41 unrelated individuals by SDS gel electrophores is and class-I-specific immunoblotting. Seven families were informativ e for the presence and absence of the 39-kD band with a clear segregat ion pattern in coupling with HLA. The data were in agreement with a co dominant expression of this molecular variant of sHLA class I. Of the 48 independent HLA haplotypes, 19 were identified as carrying the 39-k D deficiency. However, there was no clear association with HLA-B7 or g ender. Under the assumption that all haplotypes in the five noninforma tive families carried the expressed 39-kD variant, approximately 40% o f the Caucasian population should be heterozygous deficient for the 39 -kD band of sHLA class I.