Hung Huei-Mei, Lin Shih-Chieh, Su Pen-Hua, Chen Jia-Yuh
Department of Pediatrics, Chung Shan Medical University Hospital, No. 110, Sec. 1, Chien-Kuo North Road, Taichung 402, Taiwan.
Acta Paediatr Taiwan. 2003 Mar-Apr;44(2):101-3.
Aniridia is a rare condition occurring in 1 in 64,000 to 1 in 96,000 live births. Approximately one third of cases are sporadic and carry a 30% risk of Wilms' tumor developing before the age of 5. The remaining 66% are inherited in an autosomal dominant fashion. The aniridia candidate gene (PAX6) has a key role as a master regulator in the development of eye and central nervous tissues. The Wilms' tumor predisposing gene (WT1) plays an important role in the development of genitourinary tract diseases such as hypospadias, cryptorchism, horse-shoe kidney, and Wilms' tumor. The WT1 and PAX6 genes are about 700 kb apart, with the WT1 gene located centromeric to PAX6 in chromosome 11p13. We report a patient with incomplete aniridia, ptosis, hypospadias, and cryptorchism. Cytogenetic analysis revealed the presence of a de novo reciprocal translocation 46, XY, t (2; 11) (p25.1; p13) without microscopic deletion. We suggest that haploinsufficiency in PAX6 and WT1 genes resulted in aniridia and associated genitourinary abnormalities.
无虹膜症是一种罕见病症，在每64,000至96,000例活产婴儿中出现1例。约三分之一的病例为散发性，5岁前患肾母细胞瘤的风险为30%。其余66%为常染色体显性遗传。无虹膜症候选基因（PAX6）作为眼和中枢神经组织发育的主要调节因子发挥关键作用。肾母细胞瘤易感基因（WT1）在诸如尿道下裂、隐睾症、马蹄肾和肾母细胞瘤等泌尿生殖道疾病的发生中起重要作用。WT1和PAX6基因相距约700 kb，WT1基因位于11号染色体p13区域中PAX6基因的着丝粒侧。我们报告了1例患有不完全性无虹膜症、上睑下垂、尿道下裂和隐睾症的患者。细胞遗传学分析显示存在一种新发相互易位46, XY, t(2; 11)(p25.1; p13)，无微观缺失。我们认为PAX6和WT1基因的单倍剂量不足导致了无虹膜症及相关泌尿生殖系统异常。
