PUBLICATION

Exome sequencing and functional studies in zebrafish identify WDR8 as the causative gene for isolated Microspherophakia in Indian families

Authors
Madhangi, M., Dutta, D., Show, S., Bhat, V.K., Rather, M.I., Tiwari, A., Singh, N., Duvvari, M.R., Murthy, G.J., Kumar, A., Nongthomba, U.
ID
ZDB-PUB-210312-6
Date
2021
Source
Human molecular genetics   30(6): 467-484 (Journal)
Registered Authors
Nongthomba, Upendra
Keywords
none
MeSH Terms
  • Adult
  • Animals
  • Child
  • Corneal Diseases/etiology
  • Corneal Diseases/metabolism
  • Corneal Diseases/pathology*
  • Ectopia Lentis/etiology
  • Ectopia Lentis/metabolism
  • Ectopia Lentis/pathology*
  • Exome*
  • Exome Sequencing/methods*
  • Female
  • Glaucoma/etiology
  • Glaucoma/metabolism
  • Glaucoma/pathology*
  • HeLa Cells
  • Humans
  • India
  • Iris/abnormalities*
  • Iris/metabolism
  • Iris/pathology
  • Male
  • Mutation*
  • Pedigree
  • Proteins/genetics*
  • Proteins/metabolism
  • Young Adult
  • Zebrafish
PubMed
33693649 Full text @ Hum. Mol. Genet.
Abstract
Isolated Microspherophakia (MSP) is an autosomal recessive disorder characterised by a smaller than normal spherical lens. Till date, LTBP2 is the only gene shown to cause MSP. We used homozygosity mapping and whole-exome sequencing and identified a homozygous mutation, c.1148C > T (p.Pro383Leu), in the WDR8 (or WRAP73) gene in two Indian MSP families. In vitro experiments showed that the missense mutation renders the protein unstable. WDR8 is a centriolar protein that has important roles in centrosomal assembly, spindle pole formation, and ciliogenesis. Co-immunoprecipitation experiments from HeLa cells indicated that the mutation interferes with the interaction of WDR8 with its binding partners. In zebrafish, both morpholino-mediated knockdown and CRISPR/Cas knockout of wdr8 resulted in decreased eye and lens size. The lack of wdr8 affected cell cycle progression in the retinal cells, causing a reduction in cell numbers in the retina and lens. The reduction in eye size and the cell cycle defects were rescued by exogenous expression of the human wild type WDR8. However, the human mutant WDR8 (p.Pro383Leu) was unable to rescue the eye defects, indicating that the missense mutation abrogates WDR8 protein function. Thus, our zebrafish results suggested that WDR8 is the causative gene for MSP in these Indian families.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping