Thirteen Hungarian families that exhibited inherited
catalase deficiencies have been detected. Differences between the deficiencies reported from Hungary and the previously reported Swiss
acatalasemia were characterized using biochemical analysis of the
catalase proteins. Molecular
biological methods were used to compare the previously reported types of
catalase deficiencies in Japan and the Hungarian deficiencies. Three mutations (a GA insertion in exon 2, a G insertion in exon 2, and a T to G substitution in intron 7) are responsible for decreased
catalase activity in 7 of the 13 Hungarian kindreds; the other 6 families have not yet been characterized. These are not the mutations observed in Japan. Changes in
lipid and carbohydrate metabolism and the high incidence (12.7%) of
diabetes mellitus in the Hungarian kindreds suggest that individuals with inherited
catalase deficiency are at risk of
atherosclerosis and
diabetes mellitus. The Hungarian subjects were detected during screening of a large population for
catalase activity; no overt disease state was associated with the deficiencies. We hypothesize that the increased risk of disease may be due to prolonged exposure to elevated levels of blood
hydrogen peroxide due to the lack of normal removal of
hydrogen peroxide by blood
catalase.