An Hinf1 associated restriction length polymorphism pattern is reported for the catalase gene of Hungarian normocatalasemic individuals and acatalasemie patients. The 2.4-kb pCAT 10 probe revealed 9 bands (2.1, 1.5, 1.2, 1.1, 0.9, 0.8, 0.6, 0.5 and 0.4 kb) with 9 distinct patterns for the controls. The same patterns were detected for the Hungarian acatalasemie patients. The examination of the A to T mutation of the Hungarian acatalasemie patients and their relatives at position -21 in the flanking region with Hinf1 polymorphism could not reveal any difference between the acatalasémie and the normocatalasemic catalase gene.