Studio dell’esoma mediante tecnologie di genotipizzazione ad alta efficienza: sequenziamento di nuova generazione (ngs) e ibridazione genomica comparativa (cgh), per l’identificazione di nuovi geni malattia in patologie neuromuscolari.

Abstract

Over the years many different approaches and techniques have been employed to get insight genetic data of family and patients. The first approach for genetic studies and gene discovery was the linkage analysis, but to be efficient it required large family or large numbers of patients sharing the same disease phenotype. The advent of sequencing technology made the genetic analysis more handy but still it was time consuming and not cost effective when a large number of genes needed to be screened , for example in case of diseases with a known genetic heterogeneity as the neuromuscular disorders (NMDs). The high throughput molecular diagnostics tools such as Comparative Genomic Hybridization (CGH) and next Generation Sequencing (NGS) technology are changing medical genomics by accelerating new disease causing mutations discovery; these techniques could enable quick, reliable and cost-effective analysis of numerous NMD genes in parallel. The NGS methods promise to speed up the discovery of the genetic causes of diseases both in the research and the clinical setting. We performed whole exome sequencing analysis (WES) through NGS technology on a family with a Bethlem phenotype (BM) orphan of mutations in COLVI genes and a coohort of patients with a clinical diagnosis of myofibrillar myopathy (MFM). We performed the linkage analysis on BM family; the linkage regions identified were used as filters in WES output data. We selected four components (two affected and two unaffected) of this family and performed Whole Exome Sequencing by Illumina GAIIe platform obtaining a few candidate genes. Regarding the MFMs patients, we identified a large rearrangements in laminin alpha 2 (LAMA2) gene through CGH; while WES identified small variations in five patients: mutations in a known gene, and two variations in two novel genes previously unreported as involved in MFMs.