Abstract
Seventy-nine abnormal alleles of low density lipoprotein receptor (LDLR) gene in unrelated Japanese patients with familial hypercholesterolemia (FH) were screened and the following results were obtained:
1. A new variant of the LDLR gene with a 6kb deletion was found in four patients (FH Tonami-1). In the family of one of these four, neonatal diagnosis of FH was possible by checking this deletion.
2. Another variant of LDLR gene with approximately 10kb deletion was detected in five patients (FH Tonami-2). Patient H. Y., whose LDLR activity showed the same level as “heterozygote”, was revealed to have two copies of this mutant alleles and to be “true homozygote”.
3. The frequencies of these large structural alterations in the LDLR gene were 5.1% (FH Tonami-1) and 7.6% (FH Tonami-2).
