抄録
LCAT mass and its activity were measured in Japanese cases with familial LCAT deficiency. They were the menbers of the third family found in Japan.
Haptoglobin types were 2-2 in all cases. Among plasma apoproteins, A-I, A-II, B, D levels were decreased in a homozygote. In heterozygotes, plasma apoprotein levels were almost normal. Plasma cholesterol-cholesterol ester ratio was 60-70% of normal range even in heterozygotes. Plasma LCAT activity was below 10% of normal range in a homozygote and 60% in heterozygotes, these were similar to other cases previously reported. Plasma LCAT mass was 35% in a homozygote and almost normal in heterozygotes. In other reports, LCAT mass was undetectable in homozygotes and 50% in heterozygotes. In this Japanese family, homozygote has no LCAT activity but has 35% of normal LCAT mass. Heterozygotes have half-normal activity and normal mass. This suggests that deficiency of LCAT activity in this family is caused by presence of LCAT like protein which has no activity.
