Mutation analysis of PAX6 gene in a large Chinese family with aniridia.
BACKGROUND
Mutations in PAX6 gene have been shown to be the genetic cause of aniridia, which is a severe panocular eye disease characterised by iris hypoplasia. However, there is no study to do genetic analysis of aniridia, although there are several case reports in China. Here, we describe a mutation analysis of PAX6 in a large Chinese family with aniridia.


METHODS
Genomic DNA from venous blood samples was prepared. Haplotype analysis was performed with two genetic markers (D11S904 and D11S935). Fourteen exons of the PAX6 gene were amplified from genomic DNA. Polymerase chain reaction (PCR) products of each exon were analysed by single strand conformational polymorphism (SSCP). The PCR products having an abnormal pattern were sequenced to confirm the mutation.


RESULTS
Significant evidence for allele sharing in affected patients was detected suggesting that PAX6 mutation links to aniridia in this family. An extra band corresponding to exon 9 in PAX6 was found by single strand conformational polymorphism analysis in all the aniridia patients in this family, but not detected in the unaffected members. A mutation of C to T was detected by sequencing at the nucleotide 1080 that converts the Arg codon (CGA) to the termination codon (TGA).


CONCLUSIONS
Aniridia is caused by a nonsense mutation of PAX6 gene in the large Chinese kindred. Genetic test is important to prevent the transmission of aniridia to their offsprings in the kindred by prenatal diagnosis.
Song
Shu-juan
SJ
Peking University Stem Cell Research Center, Beijing 100083, China.
Liu
Ying-zhi
YZ
Cong
Ri-chang
RC
Jin
Ying
Y
Hou
Zhi-qiang
ZQ
Ma
Zhi-zhong
ZZ
Ren
Guo-cheng
GC
Li
Ling-song
LS
D015783:Aniridia / Q000235:genetics*; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D010375:Pedigree; D012097:Repressor Proteins / Q000235:genetics*
D005136:Eye Proteins; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins