Molecular Studies of Familial Hypercholesterolemia
| Autor: | Ai-Chun Huang, 黃愛純 |
|---|---|
| Rok vydání: | 2001 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 89 FH is an autosomal dominant disorder of lipoprotein metabolism, primarily caused by mutation in the LDLR gene. FH patients have elevated plasma LDL cholesterol and generally developed coronary heart disease. The study used the multiplex PCR, SSCP and DNA sequence analyses to examine the LDLR gene of 36 hyperlipidemic patients and 2 FH patients in Taiwan. A point mutation (C-to-A transversion in codon 308) and a deletion mutation Del exons 6-8 (deletion of 123 amino acids on exons 6-8) were found. The two mutations and six previously identified mutations (W-18X, D69N, I402T, A410T, I602V, A696G) were further characterized. By PCR and DdeI restriction analysis, none of the daughters inherited the W-18X mutation from D102. By MfeI restriction analysis, the D69N mutation was found in A133's son and grandson. The results of haplotype analysis suggest that the D69N alleles of A133 and L41 are likely identical by descent. Patient D63 was homozygous for the C308Y mutation. By AccI restriction analysis, both her parents and three of her siblings also carry the mutation. The mutation cosegregated with hypercholesterolemia in this family. The same haplotype of two C308Y alleles in D63 was resulted from consanguineous marriage. Comparison of this haplotype with that reported in two Chinese patients in Hong Kong suggests that the C308Y mutation arose in a common ancestor of Chinese origin. The novel I602V polymorphism was found in 3 hyperlipidemic patients and 2 normolipidemic controls. By PstI restriction analysis, the D162's son did not inherit the mutation A696G. Due to not seen in normal controls, A696G may be a novel mutation or a rare variant. The deletion Del exons 6-8 was caused by intrastrand recombination event between Alu sequences in introns 5 and 8. The same haplotype of two Del exons 6-8 alleles in D254 was resulted from consanguineous marriage. Fifteen of the recruited family members also carry the deletion. The deletion co-segregated with hypercholesterolemia in this family. In transfected COS-7 cells, wild type LDLR cDNA expressed 160 kDa mature and 120 kDa precursor proteins. An apparent reduction in LDLR mRNA level (40% of wild type) and a novel precursor protein were seen in D69N transfected cells. Although normal amount of LDLR mRNA was seen with the C308Y, I402T and A410T mutations, the amount of mature protein was less than that of wild type. The LDLR mRNA and protein levels were close to those of wild type in A696G transfected cells. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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