Objective: To investigate genetic etiology of fetal urinary abnormalities with array-based comparative genomic hycridization(array-CGH).
Methods: Thirty-two fetuses with variable urinary abnormalities but normal karyotyping by conventional cytogenetic technique were selected. DNA from the fetuses and their parents samples were prepared and hybridization with Affymetrix cytogenetic 2.7M arrays by follwing the manufacture's standard protocol. The data were analyzed by special CHAS software packages.
Results: By using array-CGH detection, genomic imbalanced copy number variations (CNVs) were identified in night fetuses(28%), four out of night CNVs were inherited from parental samples; two were indicated to be benign variants(6%) in the database; and the other three CNVs (9%) were all de novo adjacent microdeletions and microduplication mapping on to common chromosome 1q21.1 region, within which was genitourinaty system function associated gene PDZK1.
Conclusion: The incidence of genomic unbalanced variations in fetuses with congenital urinary malformations is approximately 28%, including about 9% pathogenic variations. Copy number variations (CNVs) of chromosome 1q21.1 region are associated with congenital urinary malformations which may be due to haploinsufficiency or overexpression of PDZK1 gene.