Application of classical and next generation sequencing techniques to gene discovery and diagnostics in neurogenetic disorders

Neurogenetic diseases are a genetically and phenotypically diverse set of diseases that affect the skeletal muscle, central and peripheral nervous systems. This heterogeneity, combined with the relative rareness of each individual disease type, makes identification of novel disease genes and molecular diagnosis difficult endeavours, resulting in the majority of patients going without a molecular diagnosis.
In this thesis, next generation sequencing as well as classical methods were used to facilitate disease gene discovery and molecular diagnosis in a set of novel disease phenotypes, and next generation sequencing was used in the implementation of a neurogenetic sub-exomic sequencing panel, designed to target 336 neurogenetic and cardiac disease genes for diagnostic purposes.
A single novel disease gene Kelch and BTB-domain containing 13 (KBTBD13) was identified using the classical disease gene discovery methods of linkage analysis and positional cloning. Using next generation sequencing, and classical methods, three novel disease genes (KLHL40, KLHL41, SPEG) were identified, and the phenotypic spectrum of four known disease genes (CFL2, ECEL1, GBE1, TTN) were expanded. The neurogenetic sub-exomic sequencing panel has been successfully deployed as a front-line diagnostic test in Australasia, with a diagnostic success rate of up to 34%.
The results of this thesis support the current trend in disease gene discovery and molecular diagnosis – that next generation sequencing is being translated from a purely research-based tool into one that can be applied on a routine basis to enhance the health of the population. The pace of disease gene discovery is expected to intensify with the increased availability of next generation sequencing technologies, and the influx of improved sequencing methods.