Abstract
Purpose: :
Aniridia is a rare congenital panocular disorder caused by the mutations of the PAX6 gene. The PAX6 gene is also involved in other anterior segment malformations including Peters anomaly. We studied the PAX6 gene mutations in a cohort of affected patients with aniridia, coloboma of iris and choroids, and anterior segment malformations.
Methods: :
Six unrelated families and ten sporadic patients were examined clinically. After informed consent was obtained, genomic DNA was extracted from the venous blood of all participants. Mutation screening of all exons of the PAX6 gene was performed by direct sequencing of PCR-amplified DNA fragments. Multiplex ligation-dependent probe amplification (MLPA) was performed to detect large deletions.
Results: :
By clinical examination, the patients and the pedigrees were divided into the following three groups: aniridia, coloboma of iris and choroids, and the anterior segment malformations including peters anomaly. Sequencing of the PAX6 gene, four intragenic mutations were identified in two families and two sporadic patients. The novel missense mutation c.643T>C (p.S216P) located in the homeodomain (HD) of the PAX6 cause peters anomaly with different expressing in family A6. The novel heterozygous splicing-site mutations c.357-3C>G (p.Ser119fsX32) was detected in a small family A1 with aniridia. Through MLPA analysis, a large deletion including the whole PAX6 gene and DKFZ p686k1684 was detected in one sporadic patient with aniridia.
Conclusions: :
Our findings expand the spectrum of the PAX6 gene mutations and further confirmed that different kind of mutations might cause different ocular phenotype.
Keywords: mutations • iris