Diagnosis of rare inherited diseases

Delineation of the genetic basis of rare inherited diseases can provide diagnostic certainty and risk assessment for affected individuals and their families. Determination of the genes that are mutated in such conditions can not only provide important insights into disease pathogenesis, but have frequently been shown to shed important light on the molecular pathology of common complex disorders, which share similar features. Crucially, disease gene identification represents the starting point for the development of novel therapeutics. This chapter describes the different types of genetic disorders – both chromosomal and monogenic – and the advances in technology, including next generation sequencing and microarrays that are driving the discovery of novel genetic mechanisms underlying human disease.