CRYBB3 gene

Overview

Gene (OMIM No.)	CRYBB3 (#123630)
Function of gene/protein	Protein: crystallin beta B3 Lens-specific protein with structural and functional components Interact with other beta crystallins and lens proteins to maintain lens transparency Also involved in lens development
Clinical phenotype (OMIM phenotype no.)	Cataract 22, multiple types (#609741)
Inheritance	Autosomal recessive Autosomal dominant
Ocular features	Congenital cataracts (cortical, nuclear, anterior or posterior polar) Glaucoma reported in two patients with heterozygous p.Val194Glu mutation
Systemic features	No extraocular features have been reported
Key investigations	B-scan USS to measure axial length to document microphthalmia and detect any posterior segment abnormalities Electrophysiology TORCH screen MRI brain and orbit Assessment with a paediatrician if suspicious of systemic involvement
Molecular diagnosis	Next generation sequencing Targeted gene panels (cataract) Whole exome sequencing Whole genome sequencing
Management	Ocular Management of congenital cataract
Therapies under research	None at present
Further information	OMIM

Aarts HJ, Den Dunnen JT, Lubsen NH, Schoenmakers JG. Linkage between the beta B2 and beta B3 crystallin genes in man and rat: a remnant of an ancient beta-crystallin gene cluster. Gene. 1987;59(1):127‐135
Lampi KJ, Ma Z, Shih M, et al. Sequence analysis of betaA3, betaB3, and betaA4 crystallins completes the identification of the major proteins in young human lens. J Biol Chem. 1997;272(4):2268‐2275
Qi Y, Jia H, Huang S, et al. A deletion mutation in the betaA1/A3 crystallin gene ( CRYBA1/A3) is associated with autosomal dominant congenital nuclear cataract in a Chinese family. Hum Genet. 2004;114(2):192‐197
Riazuddin SA, Yasmeen A, Yao W, et al. Mutations in betaB3-crystallin associated with autosomal recessive cataract in two Pakistani families. Invest Ophthalmol Vis Sci. 2005;46(6):2100‐2106
Reis LM, Tyler RC, Muheisen S, et al. Whole exome sequencing in dominant cataract identifies a new causative factor, CRYBA2, and a variety of novel alleles in known genes. Hum Genet. 2013;132(7):761-770

Updated on November 30, 2020