Rapid detection of three point mutations in the LDL receptor gene causing familial hypercholesterolemia among French Canadians

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · American Journal of Human Genetics

OSTI ID:134351

Vohl, M C; Mooriani, S; Torres, A L ^[1]

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1. Lipid Research Center, Quebec (Canada); and others

The frequency of familial hypercholesterolemia (FH) is 1:500 in most populations and 1:154 among French Canadians (FC) in northeastern Quebec. FH is caused by numerous mutations in the LDL receptor gene; however, among FC five mutations are responsible for FH and these are two large deletions and three missense mutations. Due to the limited number of mutations, the diagnosis of FH at the molecular level is feasible in FC and, therefore, we have developed new approaches for rapid detection of the three point mutations using PCR amplification of genomic DNA with specific primers and size separation of fragments after digestion with appropriate restriction enzymes. The point mutation in exon 3 (W66G) results from a T to G transversion. After PCR amplification of exon 3 with an exonic and a mismatch primer, DNA samples from normal subjects contain a mismatch three nucleotides upstream the mutant nucleotide 259, thus creating a BglII restriction site. The presence of the mutation at nucleotide 259 abolishes the BglII site. Another missense mutation in FC is due to a G to A transition in exon 4 (E207K). The same approach was used for the deletion of this missense mutation. After amplification, DNA samples from normal subjects contains a mismatch two nucleotides downstream from the mutant nucleotide at position 682, thus creating an MboII restriction site. In FH patients bearing the E207K mutation, the MboII site is abolished. The third missense point mutation in FH patients is located in exon 14 and is caused by a G to A transition (C646Y). The mismatch primer approach was used for rapid detection. The presence of a mismatch one nucleotide upstream from the 2000 mutant and the C646Y mutation create a NlaIII restriction site. In normal subjects, the absence of the mutation abolishes this restriction site. These new methodologies for rapid detection will be useful for both early screening and population genetic studies of FH.

• OSTI ID: 134351
• Report Number(s): CONF-941009--
• Journal Information: American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
AMINO ACIDS
CANADA
CHOLESTEROL
DETECTION
EFFICIENCY
GENE MUTATIONS
GENES
METABOLIC DISEASES
NUCLEOTIDES
PATIENTS
POLYMERASE CHAIN REACTION
RECEPTORS
SCREENING
SIZE