Founder heterozygous P23T CRYGD mutation associated with cerulean (and coralliform) cataract in 2 Saudi families.
OBJECTIVE
To assess for gammaD-crystallin (CRYGD) mutation in 2 Saudi patients with cerulean cataract and in a brother of one of the patients who had coralliform cataract.


METHODS
Patients and all of their available relatives underwent ophthalmic examination and subsequent sequencing of the candidate gene CRYGD.


RESULTS
In the first family, a 4-year-old boy with bilateral cerulean cataract and his 6-year-old brother with similar bluish lens discoloration but in a coralliform pattern were heterozygous for the p.P23T CRYGD mutation. Their father and 2 older brothers, all of whom underwent childhood cataract surgery, also harbored the mutation while the 2 asymptomatic immediate family members did not. In the second family, a 7-year-old girl with bilateral cerulean cataract was heterozygous for the same CRYGD mutation. Details of her family history were limited. The patients in the two families shared a common disease haplotype.


CONCLUSIONS
This first report of p.P23T CRYGD mutation underlying cerulean cataract in the Saudi population strongly supports the mutation's relation with the phenotype. Coralliform cataract can represent variable expressivity for the same mutation rather than a distinct entity.
Khan
Arif O
AO
Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia. arif.khan@mssm.edu
Aldahmesh
Mohammed A
MA
Ghadhfan
Faisal E
FE
Al-Mesfer
Saleh
S
Alkuraya
Fowzan S
FS
D019943:Amino Acid Substitution / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D002386:Cataract / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005190:Family; D005260:Female; D018703:Founder Effect; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006579:Heterozygote; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D010375:Pedigree; D011392:Proline / Q000235:genetics; D012529:Saudi Arabia; D013912:Threonine / Q000235:genetics; D038222:gamma-Crystallins / Q000235:genetics*
C504903:CRYGD protein, human; D038222:gamma-Crystallins; D013912:Threonine; D011392:Proline