Double heterozygous familial hypercholesterolaemia: Case series, genetics and Cascade screening of families

Hoang Thi Yen , Vu Duc Anh, Le Thi Yen, Dang Thi Ngoc Dung

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Abstract

Background: Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipoprotein metabolism characterized by high levels of LDL-cholesterol (LDL-C) in the blood. Studies identified more than 1,000 mutations of the LDLR gene in FH patients with incidence rates between 1: 500 and 1: 300. The mutation that occurs primarily in: LDLR, apoB, PCSK9, LDLRAP1 genes, 80% of which were detected the LDLR gene mutation. Nowaday, FH disease has not been paid much attention, leading to a delay in treatment. 


Objectives: identify mutations in other family members of the patient FH. 


Subjects and Methods: 14 family members of FH patients were gene analyzed, identified mutations on exons 4, 9 LDLR genes.


Results: 11/15 family members carrying heterozygous mutations on exon 4 and exon 9 of LDLR gene. Patient and 1 family member detected and treated late, leading to complications of myocardial infarction. Conclusion: Therefore, Cascade screening of patient's family members has an important role in early detection, genetic counseling and treatment, even in cases where pedigree members do not have xanthomas and no increase or slight increase in blood lipids. This is the basis for early counseling and treatment for members with mutations, reducing the risk of coronary artery diseases in the future.

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References

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