#615188
Table of Contents
A number sign (#) is used with this entry because of evidence that multiple types of cataract (CTRCT39) are caused by heterozygous mutation in the CRYGB gene (123670) on chromosome 2q33.
Mutations in the CRYGB gene have been found to cause multiple types of cataract, which have been described as lamellar, anterior polar, and complete.
AlFadhli et al. (2012) studied a 3-generation consanguineous Kuwaiti family segregating congenital cataract of multiple types in an autosomal dominant pattern. Four family members had lamellar cataracts, including the proband and her father, her paternal grandfather, and a cousin; 2 family members had anterior polar cataracts in the pupillary region, including the paternal grandmother, who was of Egyptian origin, and another cousin; and the proband's paternal uncle had complete cataracts. There was no history of other ocular or systemic abnormalities in the family.
In a 3-generation Kuwaiti family segregating autosomal dominant congenital cataract, AlFadhli et al. (2012) performed genomewide linkage analysis and identified a region of potential linkage with a maximum lod score of 1.5 on chromosome 2q34; however, no mutations were found in the candidate gene CRYBA2 (600836) located in that region. The second highest lod score, 1.49, was obtained at 2q33-q37 and spanned the gamma-crystallin gene cluster.
The transmission pattern of cataract in the Kuwaiti family reported by AlFadhli et al. (2012) was consistent with autosomal dominant inheritance.
In a 3-generation Kuwaiti family with autosomal dominant congenital cataract mapping to chromosome 2q33-q37, AlFadhli et al. (2012) screened the 4 candidate gamma-crystallin genes, CRYGA (123660), CRYGB (123670), CRYGC (123680), and CRYGD (123690), and identified 2 different mutations in the CRYGB gene, each with an autosomal dominant mode of inheritance. The first was a 1-bp deletion in exon 2 (123670.0001) that was maternally inherited from the Egyptian grandmother and segregated with anterior polar cataracts, and the other was a 1-bp intronic deletion (123670.0002) that was paternally inherited from the Kuwaiti grandfather and segregated with the lamellar cataract phenotype. The patient with complete cataracts was the only family member who was compound heterozygous for both mutations. Neither mutation was found in 50 age-, gender-, and ethnicity-matched controls.
AlFadhli, S., Abdelmoaty, S., Al-Hajeri, A., Behbehani, A., Alkuraya, F. Novel crystallin gamma B mutations in a Kuwaiti family with autosomal dominant congenital cataracts reveal genetic and clinical heterogeneity. Molec. Vis. 18: 2931-2936, 2012. [PubMed: 23288985, images, related citations]
ORPHA: 91492; DO: 0110236;
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
|---|---|---|---|---|---|---|
| 2q33.3 | Cataract 39, multiple types, autosomal dominant | 615188 | Autosomal dominant | 3 | CRYGB | 123670 |
A number sign (#) is used with this entry because of evidence that multiple types of cataract (CTRCT39) are caused by heterozygous mutation in the CRYGB gene (123670) on chromosome 2q33.
Mutations in the CRYGB gene have been found to cause multiple types of cataract, which have been described as lamellar, anterior polar, and complete.
AlFadhli et al. (2012) studied a 3-generation consanguineous Kuwaiti family segregating congenital cataract of multiple types in an autosomal dominant pattern. Four family members had lamellar cataracts, including the proband and her father, her paternal grandfather, and a cousin; 2 family members had anterior polar cataracts in the pupillary region, including the paternal grandmother, who was of Egyptian origin, and another cousin; and the proband's paternal uncle had complete cataracts. There was no history of other ocular or systemic abnormalities in the family.
In a 3-generation Kuwaiti family segregating autosomal dominant congenital cataract, AlFadhli et al. (2012) performed genomewide linkage analysis and identified a region of potential linkage with a maximum lod score of 1.5 on chromosome 2q34; however, no mutations were found in the candidate gene CRYBA2 (600836) located in that region. The second highest lod score, 1.49, was obtained at 2q33-q37 and spanned the gamma-crystallin gene cluster.
The transmission pattern of cataract in the Kuwaiti family reported by AlFadhli et al. (2012) was consistent with autosomal dominant inheritance.
In a 3-generation Kuwaiti family with autosomal dominant congenital cataract mapping to chromosome 2q33-q37, AlFadhli et al. (2012) screened the 4 candidate gamma-crystallin genes, CRYGA (123660), CRYGB (123670), CRYGC (123680), and CRYGD (123690), and identified 2 different mutations in the CRYGB gene, each with an autosomal dominant mode of inheritance. The first was a 1-bp deletion in exon 2 (123670.0001) that was maternally inherited from the Egyptian grandmother and segregated with anterior polar cataracts, and the other was a 1-bp intronic deletion (123670.0002) that was paternally inherited from the Kuwaiti grandfather and segregated with the lamellar cataract phenotype. The patient with complete cataracts was the only family member who was compound heterozygous for both mutations. Neither mutation was found in 50 age-, gender-, and ethnicity-matched controls.
AlFadhli, S., Abdelmoaty, S., Al-Hajeri, A., Behbehani, A., Alkuraya, F. Novel crystallin gamma B mutations in a Kuwaiti family with autosomal dominant congenital cataracts reveal genetic and clinical heterogeneity. Molec. Vis. 18: 2931-2936, 2012. [PubMed: 23288985]
Dear OMIM User,
To ensure long-term funding for the OMIM project, we have diversified our revenue stream. We are determined to keep this website freely accessible. Unfortunately, it is not free to produce. Expert curators review the literature and organize it to facilitate your work. Over 90% of the OMIM's operating expenses go to salary support for MD and PhD science writers and biocurators. Please join your colleagues by making a donation now and again in the future. Donations are an important component of our efforts to ensure long-term funding to provide you the information that you need at your fingertips.
Thank you in advance for your generous support,
Ada Hamosh, MD, MPH
Scientific Director, OMIM