The Frequency in Japan of Carriers of the Rare “Recessive” Gene Causing Acatalasemia

Although it is increasingly recognized that many rare recessive genes have effects in the heterozygous state which can be detected by suitable laboratory tests, with the implication that such genes may make a significant contribution to subclinical departures from health, there is a real paucity of knowledge concerning the actual distribution in populations of such heterozygotes.Until now it has not been possible to study the distribution of heterozygotes for a rare "recessive" gene with a simple, quick, and accurate method suitable for survey purposes.It will be the object of this paper to describe such a method for detecting the heterozygous carriers of a particular rare "reces- sive" gene.Survey data will be presented indicat- ing significant local variations in gene frequency.The implications of such variations for certain basic genetic problems will be briefly explored.The trait in question is acatalasemia, a reces- sively inherited condition characterized by the ab- sence of detectable tissue catalase activity (1).Heterozygotes for this gene have been shown to exhibit approximately half-normal values of cata- lase activity (2).In a previous paper, it was noted that the application of standard genetic formulae led to an estimate of 0.003 for q, the frequency of the gene responsible for the trait, from which the frequency of homozygotes was calculated to be 0.00002, and of heterozygotes, 0.006; i.e., 2 and 600 per 100,000 Japanese, respectively (3).The many assumptions which went into these calcula- tions were discussed briefly, with the statement that in general the computations were of such a