title: Homozygous familial hypercholesterolemia in Lebanon: a genotype/phenotype correlation.
abstract: Familial hypercholesterolemia (FH) is an inherited disease characterized by the deposition of LDL in tissues causing premature atherosclerosis. Many genes are implicated in FH resulting in a large variability in the phenotype. DNA sequencing of the LDLR gene was done for forty patients clinically diagnosed with homozygous FH and forty family members variably affected. Patients underwent noninvasive heart and vascular studies. Statistical and pedigree analyses were used to correlate the different genotypes with the phenotypes. The prevalence of homozygosity at the Lebanese allele (2043C>A) is 45%. However, 27.5% of the patients have no mutations at all in the LDLR gene, and 27.5% are either heterozygous for the 2043C>A mutation, heterozygous for a mutation in another exon of the LDLR gene, or combined heterozygous for two different mutations. We confirm previous reports on the higher prevalence of FH in Lebanon. Our results do, however contradict previous reports on an assumed higher prevalence among the Christian Lebanese. Mutations in the LDLR especially combined heterozygosity can cause a severe phenotype similar to the homozygous mutation in the Lebanese allele. This information is particularly important in targeting the more prevalent heterozygotes in the general population with early diagnosis and intervention.
authors.affiliation: Department of Biochemistry, American University of Beirut, Bliss Street, Beirut, Lebanon.
authors.forename: Akl C
authors.initials: AC
authors.lastname: Fahed
authors.forename: Raya M
authors.initials: RM
authors.lastname: Safa
authors.forename: Fadi F
authors.initials: FF
authors.lastname: Haddad
authors.forename: Fadi F
authors.initials: FF
authors.lastname: Bitar
authors.forename: Rabih R
authors.initials: RR
authors.lastname: Andary
authors.forename: Mariam T
authors.initials: MT
authors.lastname: Arabi
authors.forename: Sami T
authors.initials: ST
authors.lastname: Azar
authors.forename: Georges
authors.initials: G
authors.lastname: Nemer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D056726:Genetic Association Studies; D006720:Homozygote; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000453:epidemiology* / Q000235:genetics*; D007861:Lebanon / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing; D009154:Mutation / Q000235:genetics; D010375:Pedigree; D011973:Receptors, LDL / Q000235:genetics*; D055815:Young Adult
chemical_list: D008078:Cholesterol, LDL; D011973:Receptors, LDL