Defining the genetic and molecular basis of inherited eye diseases present in Pakistan

Abstract

Human Mendelian genetics aims to define the link between the phenotypical manifestations of a disease, and the identity of the gene that when mutated causes disease. Rare ocular genetic disorders are typically difficult to manage due to an incomplete understanding of their genetic causes and clinical outcomes. However, in the last few years rapid advancements in high throughput genomic sequencing techniques has paved the way for the discovery of new genes causing inherited diseases, and provided new insights into the breadth of phenotypical manifestations associated with pathogenic variants in genes already known to be linked with ocular disease. The discovery of new disease-associated genes provides important diagnostic benefits for patients, and also aids scientific understanding of how the biological processes within cells work. In turn, this drives the development of new treatments and therapies. Chapter three documents a comprehensive series of genetic studies leading to the discovery of a novel founder mutation in the CLCC1 gene, associated with an autosomal recessive form of retinitis pigmentosa in families from Pakistan, as well as the characterisation of CLCC1 in zebrafish and mouse retina. Moreover, the chapter details extensive molecular studies to discover the functional role of CLCC1 in the cells. This includes the localisation of CLCC1 within the endoplasmic reticulum, the identification of CLCC1 binding partners, and the exploration of a possible role of CLCC1 in endoplasmic reticulum stress and calcium signalling. This section also describes the generation of a CLCC1 knockout cell line using CRISPR-Cas9, to enable future more extensive studies of CLCC1 molecular function. 3 Chapter four of this thesis entails a comprehensive investigation by way of genetic studies, and literature review, of novel and known genetic variants associated with a wide range of inherited retinal dystrophies in families from Pakistani. This data provides the most comprehensive repository of information available for designing molecular diagnostic testing approaches in the region.