Low density lipoprotein receptor mutations in a selected population of individuals with moderate hypercholesterolemia.
To evaluate mutations in the low density lipoprotein receptor (LDL-R) gene in moderate primary hypercholesterolemia, a combination of polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP) and direct sequencing, was used to screen the LDL-R gene in a selected population of 82 unrelated individuals with moderate elevation of plasma LDL-C [mean 4.55 +/- 0.55 mmol/l (176.4 +/- 21.6 mg/dl)]. Four subjects (5%) were found to be heterozygotes for missense mutations in the LDL-R gene. These mutations were located in four different exons (exons 6, 7, 15 and 17) and all alters highly conserved residues of LDL-R protein. None of these mutations were detected in 79 normocholesterolemic individuals. The mutation in exon 15 (T705I) was previously reported in a compound heterozygote for familial hypercholesterolemia (FH). In the proband carrying the mutation in exon 17 (R793Q), an in vivo LDL turnover study was performed and it demonstrated a reduction of LDL catabolism. These findings demonstrate that mutations in the LDL-R may occur in primary moderate hypercholesterolemia. They also extend the concept that some FH patients may present with a mild phenotype.
Arca
M
M
Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, USA.
Jokinen
E
E
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D005091:Exons; D006801:Humans; D006937:Hypercholesterolemia / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011973:Receptors, LDL / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D011973:Receptors, LDL