Preferred Label : Crystallin, beta-b1;
Obsolete resource : true;
Alternative titles and symbols : Crybb1cataract, pulverulent;
Description : For background information on the beta-crystallin genes, see 123610. Den Dunnen et
al. (1986) cloned and characterized the rat beta-crystallin-B1 gene. The gene has
5 exons, the first 4 of which encode distinct protein motifs. The predicted protein
contains 247 amino acids and is about 55% similar to the bovine homolog (Den Dunnen
et al., 1985). Hulsebos et al. (1995) mapped the human and mouse crystallin beta-B1
genes. PCR primers were designed based on the previously reported rat sequence. The
human gene was localized in the region 22q11.2-q12.1 using a somatic cell hybrid DNA
panel that included characterized deletions of that chromosome. The mouse homolog
was mapped to the central part of chromosome 5 using interspecific backcross analysis.
In both species this crystallin is linked to other members of the family, including
CRYBA4 (123631), CRYBB2 (123620), and CRYBB3 (123630). Stempel et al. (2003) identified
beta B1-crystallin as a new cytoplasmic ciliary body antigenic target of perinuclear
anti-neutrophil cytoplasmic antibody. This characterization of beta B1-crystallin
outside the lens raised questions about its extralenticular expression, intracellular
role, and potential target of inflammation in uveitis. In a family with autosomal
dominant pulverulent cataract, Mackay et al. (2002) found that the disorder mapped
to the beta-crystallin gene cluster on 22q11.2. Sequencing of the CRYBB1 gene detected
a G-to-T transversion in exon 6 of the CRYBB1 gene that cosegregated with cataract
in the family. This single-nucleotide change was predicted to introduce a translation
stop codon at glycine 220 (G220X; 600929.0001). Central pulverulent, or powdery, opacities
had previously been linked with the CRYGC gene (123680) on 2q and the CRYBB2 gene
on 22q. In 2 unrelated consanguineous inbred Bedouin families from southern Israel
presenting with autosomal recessive congenital nuclear cataract (CATCN3; 611544),
Cohen et al. (2007) identified an identical homozygous deletion mutation (168delG;
600929.0002) in the CRYBB1 gene in affected individuals of both families. *FIELD*
AV .0001;
Origin ID : 600929;
UMLS CUI : C1413729;
Currated CISMeF NLP mapping
- ORDO concept(s)
- Semantic type(s)
- UMLS correspondences (same concept)
