Male fertility in factor XIII deficiency

Seven homozygotes for F-XIII deficiency were found in a large inbred Israeli-Arab kindred. One affected woman had early abortions. Two affected men and one probably affected man had children, two of whom also were affected. Paternity was confirmed by segregation of HLAs and erythrocyte antigens and enzymes. This is the first documentation of normal male fertility in unequivocally affected patients. Clinical variability or genetic heterogeneity may account for previously reported male infertility.