Identification of the gene defect responsible for severe hypercholesterolaemia using whole-exome sequencing

Abstract

Familial hypercholesterolaemia (FH) is a serious genetic metabolic disease. We identified a specific family in which the proband had typical homozygous phenotype of FH, but couldn’t detect any mutations in usual pathogenic genes using traditional sequencing. This study is the first attempt to use whole exome sequencing (WES) to identify the pathogenic genes in Chinese FH. The routine examinations were performed on all parentage members, and WES on 5 members. We used bioinformatics methods to splice and filter out the pathogenic gene. Finally, Sanger sequencing and cDNA sequencing were used to verify the candidate genes. Half of parentage members had got hypercholesterolaemia. WES identified LDLR IVS8[−10] as a candidate mutation from 222,267 variations. The Sanger sequencing showed proband had a homozygous mutation inherited from his parents, and this loci were cosegregated with FH phenotype. The cDNA sequencing revealed that this mutations caused abnormal shearing. This mutation was first identified in Chinese patients, and this homozygous mutation is a new genetic type of FH. This is the first time that WES was used in Chinese FH patients. We detected a novel genetic type of LDLR homozygous mutation. WES is powerful tools to identify specific FH families with potentially pathogenic gene mutations.

The distribution and characteristics of LDL receptor mutations in China: A systematic review

“…Our group later conducted touch-down PCR together with DNA sequencing and denaturing high-performance liquid chromatography (DHPLC) to detect LDLR mutations 6 43 . We also conducted the first study to utilize an SNP-based genome-wide linkage scan and whole/targeted exome sequencing technologies to detect LDLR mutations in China 8 10 44 .…”

The use of targeted exome sequencing in genetic diagnosis of young patients with severe hypercholesterolemia

“…A total of 27 mutations in LDLR gene were identified (Table S1). There was no mutation found by DNA resequencing array in proband 11, even though a c.1187–10 G>A mutation was detected by the whole-exome sequencing method in a previous study11. In the DNA array group, a total of 16 mutations were identified across the 12 probands tested with DNA array.…”

“…Therefore, there is a pressing clinical incentive to develop effective screening methods420 for the early detection of FH. In a previous study, we used whole exome sequencing and TES to identify patients with HoFH and found that these technologies are useful for providing an accurate genetic diagnosis in patients with severe hypercholesterolemia1011. In the present work, we have analyzed 20 young patients with severe hypercholesterolemia by either array sequencing or TES.…”

“…DNA samples from 12 patients were processed using DNA resequencing array7, samples from 14 patients were processed by targeted exome sequencing10, and samples from 6 patients were processed by both methods. Some probands were reported in previous studies11132526. This study was approved by the Research Ethics Committee of Beijing Anzhen Hospital in China.…”

Long-Term Follow-up of a Homozygous Familial Hypercholesterolemia Child with Progressive Aortic Stenosis and Coronary Atherosclerosis

“…The methods of DNA extraction and sequencing have been reported in our previous studies. 4 The homozygous mutation in LDLR exon9 c.1187-10G>A, a 3' splice acceptor mutation in poly-pyrimidine tract of intron 8, was detected in the child and the heterozygous form was detected in his mother.…”