Abstract
Electron microscopic studies on 3 subjects with FDIC in an additional kindred involving 7 subjects with the trait revealed that they were not concordant with those observed in the previously reported kindred. KICG values in the kindred were distributed trimodally. Although the kindred was highly inbred, the 7 subjects with the trait were off- springs of seemingly non-consanguineous parents. These results suggested an incompletely dominant inheritance or an intervention of modifier genes in the transmission of the trait in the additional kindred and genetic heterogeneity in FDIC was postulated. The incidence of the subjects with FDIC was estimated approximately 0.4% in Tsushima district.
