Ahmed W, Whittall R, Riaz M, Ajmal M, Sadeque A, Ayub H, Qamar R, Humphries SE. The genetic spectrum of familial hypercholesterolemia in Pakistan.
Clin Chim Acta 2013;
421:219-25. [PMID:
23535506 PMCID:
PMC3701840 DOI:
10.1016/j.cca.2013.03.017]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 03/13/2013] [Indexed: 12/28/2022]
Abstract
Background
Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the genes coding for the low density lipoprotein receptor (LDLR), proprotein convertase subtilisin/kexin type-9 (PCSK9) or apo-lipoprotein B-100 (APOB). The aim of the present work was to determine the genetic basis of dyslipidemia in 11 unrelated Pakistani families.
Methods
High resolution melting (HRM), sequencing and restriction fragment length polymorphism (RFLP).
Results
Probands were screened for the promoter and all coding regions, including intron/exon boundaries, of LDLR and PCSK9 and part of exon 26 of APOB including p.(R3527Q). Two families were identified with previously unreported LDLR mutations (c.1019_1020delinsTG, p.(C340L) and c.1634G>A, p.(G545E)). Both probands had tendon xanthomas or xanthelasma and/or a history of cardiovascular disease. Co-segregation with hypercholesterolemia was demonstrated in both families. In silico studies predicted these variations to be damaging. In two families, novel PCSK9 variations were identified (exon2; c.314G > A, p.(R105Q) and exon3; c.464C>T, p.(P155L)). In silico studies suggested both were likely to be damaging, and family members carrying the p.(105Q) allele had lower total cholesterol levels, suggesting this is a loss-of-function mutation. For c.464C>T p.(P155L) the small number of relatives available precluded any strong inference.
Conclusion
This report brings to seven the number of different LDLR mutations reported in FH patients from Pakistan and, as expected in this heterogeneous population, no common LDLR mutation has been identified.
We examined the LDLR/PCSK9 genes in patients with FH from Pakistan.
Two novel LDLR mutations both showed co-segregation with hypercholesterolemia.
Two novel PCSK9 variations were found one of which was a loss of function mutation.
This brings to 7 the number of molecular causes of FH in patients from Pakistan.
Collapse