A novel mutation in the major intrinsic protein (MIP) associated with autosomal dominant congenital cataracts in a Chinese family.
OBJECTIVE
To detect the underlying genetic defect in a Chinese family affected with bilateral congenital cataracts.


METHODS
A detailed family history and clinical data were recorded. Mutation screening was performed in the nuclear cataract-related gene by bidirectional sequencing of the amplified products. The mutation was verified by denaturing high-performance liquid chromatography (DHPLC).


RESULTS
Two cataract phenotypes were observed within this family: one eye exhibited Y-suture and nuclear pulverulent opacification of the lens, while the others exhibited complete opacification in the fetal nuclear region. Sequencing of the candidate genes detected a heterozygous c.319G>A change in the coding region of the major intrinsic protein (MIP), resulting in the substitution of a highly conserved Valine by Isoleucine (p.V107I).The mutation was confirmed by DHPLC.


CONCLUSIONS
This study has identified a novel MIP mutation, p.V107I in a Chinese family with congenital cataracts. To the best of our knowledge, this is the first reported case of cataracts caused by a mutation in the second extracellular loop domain of MIP.
Wang
Wei
W
Eye Center of the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China.
Jiang
Jin
J
Zhu
Yanan
Y
Li
Jinyu
J
Jin
Chongfei
C
Shentu
Xingchao
X
Yao
Ke
K
D000328:Adult; D000595:Amino Acid Sequence; D020346:Aquaporins / Q000737:chemistry / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D002386:Cataract / Q000151:congenital* / Q000235:genetics*; D002681:China; D002851:Chromatography, High Pressure Liquid; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D005136:Eye Proteins / Q000737:chemistry / Q000235:genetics*; D005190:Family; D005260:Female; D005799:Genes, Dominant / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D010375:Pedigree; D016415:Sequence Alignment
D020346:Aquaporins; D005136:Eye Proteins; D050505:Mutant Proteins; C030328:aquaporin 0