Identification of Known Mutation in LDL Receptor Gene Underlying Severe FH Phenotype in Thai Patient: A Case Report

Abstract

Objective: Familial hypercholesterolemia (FH) is associated with atherosclerosis coronary artery disease (CAD). The aim of this study is to identify a mutation in the LDL receptor gene that underlined the FH phenotype in a female patient and her family.
Methods: The LDL receptor gene was screened by Polymerase Chain Reaction-Single Strand Conformation Polymorphism (PCR-SSCP), direct DNA sequencing and was subsequently confirmed by PCR-RFLP.
Results: The screening of the entire LDL receptor gene revealed a 5' donor splice site mutation of the first base of intron 3, i.e., 313+1G➔T mutation in one allele. This mutation was previously reported in a Danish patient with severe hypercholesterolemia.
Conclusion: This case report illustrates the use of DNA diagnosis of a female heterozygous FH case and her family members, which is more accurate than clinical diagnosis especially when clinical phenotype is variable or when the individual who is at high risk is still a normolipidemic at his/ her young age. DNA diagnosis is now used as a tool to find or diagnose FH. Accurate and/or early diagnosis is important for prevention and treatment of FH patients in order to avoid the development of CAD in these patients.