PUBLICATION

Exome capture sequencing identifies a novel mutation in BBS4

Authors
Wang, H., Chen, X., Dudinsky, L., Patenia, C., Chen, Y., Li, Y., Wei, Y., Abboud, E.B., Al-Rajhi, A.A., Lewis, R.A., Lupski, J.R., Mardon, G., Gibbs, R.A., Perkins, B.D., and Chen, R.
ID
ZDB-PUB-120111-20
Date
2011
Source
Molecular Vision   17: 3529-3540 (Journal)
Registered Authors
Perkins, Brian
Keywords
none
MeSH Terms
  • Alleles
  • Animals
  • Base Sequence
  • Chromosome Mapping
  • Consanguinity
  • Exome
  • Exons
  • Female
  • Genotype
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Infant
  • Leber Congenital Amaurosis/genetics*
  • Leber Congenital Amaurosis/metabolism
  • Leber Congenital Amaurosis/pathology
  • Male
  • Molecular Sequence Data
  • Mutation, Missense*
  • Pedigree
  • Polymorphism, Single Nucleotide
  • Proteins/genetics*
  • Proteins/metabolism
  • Retina/metabolism*
  • Retina/pathology
  • Rhodopsin/metabolism
  • Saudi Arabia
  • Zebrafish
PubMed
22219648
Abstract

Purpose

Leber congenital amaurosis (LCA) is one of the most severe eye dystrophies characterized by severe vision loss at an early stage and accounts for approximately 5% of all retinal dystrophies. The purpose of this study was to identify a novel LCA disease allele or gene and to develop an approach combining genetic mapping with whole exome sequencing.

Methods

Three patients from King Khaled Eye Specialist Hospital (KKESH205) underwent whole genome single nucleotide polymorphism genotyping, and a single candidate region was identified. Taking advantage of next-generation high-throughput DNA sequencing technologies, whole exome capture sequencing was performed on patient KKESH205#7. Sanger direct sequencing was used during the validation step. The zebrafish model was used to examine the function of the mutant allele.

Results

A novel missense mutation in Bardet-Biedl syndrome 4 protein (BBS4) was identified in a consanguineous family from Saudi Arabia. This missense mutation in the fifth exon (c.253G>C;p.E85Q) of BBS4 is likely a disease-causing mutation as it segregates with the disease. The mutation is not found in the single nucleotide polymorphism (SNP) database, the 1000 Genomes Project, or matching normal controls. Functional analysis of this mutation in zebrafish indicates that the G253C allele is pathogenic. Coinjection of the G253C allele cannot rescue the mislocalization of rhodopsin in the retina when BBS4 is knocked down by morpholino injection. Immunofluorescence analysis in cell culture shows that this missense mutation in BBS4 does not cause obvious defects in protein expression or pericentriolar localization.

Conclusions

This mutation likely mainly reduces or abolishes BBS4 function in the retina. Further studies of this allele will provide important insights concerning the pleiotropic nature of BBS4 function.

Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping