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[Genotype-phenotype analysis of a homozygous familial hypercholesterolemia pedigree].
- Source :
-
Zhonghua er ke za zhi = Chinese journal of pediatrics [Zhonghua Er Ke Za Zhi] 2020 Feb 02; Vol. 58 (2), pp. 101-106. - Publication Year :
- 2020
-
Abstract
- Objective: To analyze the genetic characteristics of a five generations pedigree with homozygous familial hypercholesterolemia (HoFH). Methods: Prospective study. Twenty family members included a proband diagnosed as familial hyperlipidemia at the cardiology Department of Xi'an Children's Hospital in October 2018 were research object. Clinical data were collected. Genome DNAs were extracted. Whole exons sequencing was performed on the proband using target capture next generation sequencing. Candidate gene mutation sites identified by bioinformatics were verified by Sanger sequencing in the family members. The genotype-phenotype correlation of the pedigree was analyzed between heterozygous mutation carriers and non-carriers. Results: The proband was a 7-years and 10-month-old boy. He was born with a roundgreen bean size yellow skin protuberance in the skin of the coccyx. Since the age of 3-4 years old, xanthoma-like lesions with a diameter of 0.5-1.5 cm gradually appeared in the skin of bilateral elbow joints, knee joints and Achilles tendon. The height, weight and intellectual development of the child were the same as those of normal children at the same age. No similar xanthoma-like lesion was found in the other family members. The proband's total cholesterol (TC) reached 18.16-21.24 mmol/L, and his low density lipoproteincholesterol (LDL-C) was 14.08-15.51 mmol/L. Carotid ultrasonography showed diffuse sclerotic plaques in bilateral carotid and vertebral arteries, and color Doppler echocardiography revealed aortic valve thickening and calcification. Gene testing identified that the proband carried a homozygous mutation C. 418G>A (p. E140K) in LDLR gene inherited from his parents who had a consanguineous marriage and carried a heterozygous mutation of LDLR-E140K, respectively.The TC, LDL-C and apolipoproteinB (ApoB) of LDLR-E140K gene heterozygous carriers ((8.40±0.13), (6.79±0.01) and (1.95±0.05) mmol/L, respectively) were significantly higher than those of non-carriers ((4.59±0.28), (3.35±0.39) and (0.86±0.10) mmol/L, t= 7.269, 4.595, 6.311, respectively, P< 0.05). Conclusions: LDLR-E140K gene homozygous mutation is first reported to be associated with most severe phenotype HoFH. The genotype-phenotype analysis of the pedigree shows that the clinical phenotype of the proband with homozygous mutation is the most serious, and all the heterozygous mutation carriers present with hypercholesterolemia phenotype. The investigation confirms that LDLR-E140K is the pathogenic variation of familial hyperlipidemia.
- Subjects :
- Aortic Valve diagnostic imaging
Base Sequence
Child
Child, Preschool
DNA Mutational Analysis
Echocardiography, Doppler
Female
Genetic Predisposition to Disease
Heterozygote
Homozygote
Humans
Hyperlipoproteinemia Type I diagnosis
Hyperlipoproteinemia Type II blood
Hyperlipoproteinemia Type II diagnosis
Infant
Lipoproteins, HDL blood
Lipoproteins, LDL blood
Male
Membrane Proteins
Mutation
Pedigree
Phenotype
Prospective Studies
Cholesterol, LDL blood
DNA genetics
Hyperlipoproteinemia Type I genetics
Hyperlipoproteinemia Type II genetics
Receptors, LDL genetics
Subjects
Details
- Language :
- Chinese
- ISSN :
- 0578-1310
- Volume :
- 58
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Zhonghua er ke za zhi = Chinese journal of pediatrics
- Publication Type :
- Academic Journal
- Accession number :
- 32102145
- Full Text :
- https://doi.org/10.3760/cma.j.issn.0578-1310.2020.02.007