CNV and LOH analysis of patient sample PN11-0204

We saw a patient who presented with respiratory distress from birth due to interstitial lung disease. Before the age of three months a diagnosis of nephrotic syndrome was made. Lung biopsy revealed pulmonary interstitial glycogenosis. Despite extensive investigations, no known genetic or infectious cause was found for the congenital nephrotic syndrome. The patient died at the age of 8 months due to respiratory failure. A 20 Mb homozygous region was identified on chromosome 17 in the patient’s DNA, revealing a novel homozygous missense variant in ITGA3 gene. Genomic DNA was obtained from peripheral blood samples of the patient with interstitial lung fibrosis and nephrotic syndrome. Copy number variation (CNV) screening by means of microarray analyses was carried out on the Affymetrix GeneChip 250k (NspI) SNP array platform (Affymetrix, Inc., Santa Clara, CA, USA), which contains 25-mer oligonucleotides representing a total of 262,264 SNPs. Hybridizations were performed according to the manufacturer’s protocols. Copy numbers and “long contiguous stretches of homozygosity” (LCSH/LOH) were determined using the 2.0 version of the CNAG (Copy Number Analyzer for Affymetrix GeneChip mapping) software package (Nannya Y, Sanada M, et al (2005) "A robust algorithm for copy number detection using high-density oligonucleotide single nucleotide polymorphism genotyping arrays." Cancer Res; 65: 6071–6079.). The average resolution of this array platform, described by McMullan et al is 150–200 kb (Mc McMullan DJ, Bonin M et al. (2009), “Molecular karyotyping of patients with unexplained mental retardation by SNP arrays: a multicenter study” Hum Mutat. Jul;30(7):1082-92).