A novel 11p13 microdeletion encompassing PAX6 in a Chinese Han family with aniridia, ptosis and mental retardation

PURPOSE: To explore possible genetic aberrations in a Chinese family with aniridia, ptosis and mental retardation, and provide genetic evidence for the prenatal diagnosis. METHODS: 14 exons of PAX6 in the proband were sequenced by the Sanger sequencing technique. Multiplex ligation-dependent probe amplification (MLPA) technique was employed to further explore gene alterations of PAX6. Single nucleotide polymorphisms-array (SNP-array) assay was applied to screen potential pathologic genome-wide copy number variations (CNV). RESULTS: There were no detectable pathogenic mutations in the 14 exons of PAX6 in the proband. MLPA indicated a heterozygous deletion encompassing all PAX6 gene regions covered and a partial upstream region. SNP-array assay detected a heterozygous 11p13 microdeletion with a length of 518 kb in the proband, spanning two whole annotated genes, elongation factor protein 4 (ELP4), the paired box gene 6 (PAX6), and partial IMP1 inner-mitochondrial membrane (IMMP1L) gene. SNP-array revealed her affected brother carried the identical deletion. CONCLUSIONS: The 518 kb heterozygous deletion in 11p13 encompassing PAX6 should be the genetic etiology for the familial aniridia.