Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterised by difficulty with social interaction and communication abilities. Repetitive behaviour is also a common feature observed in patients suffering from ASD. The symptoms surrounding ASD have an early onset and can be detected from a young age. In Ireland, the prevalence of ASD has grown from 9,234 cases reported in school students during 2011/12 up to 16,094 cases observed in school students during 2015/16, published by the Department of Health. The number of ASD incidences is increasing each year and the purpose of the research project is to identify potential variants within our genome linked with ASD. ASD has been shown from twin studies to have a hereditary aspect. The project aims to identify these hereditary variants or mutations that increase the risk of an individual having ASD. A whole exome sequencing, whole genome sequencing, genotype array and clinical exome sequencing has been carried out on a family with members diagnosed with ASD. Using these results, the current project aims to: (1) compare the sequences of ASD patients with sequences of their non-ASD members (and other ASD-patients), identifying any similarities or differences. This analysis will establish the quality of the sequence data obtained and statistically isolate disease-associated risk variants. (2) draft a report hypothesising the clinical role of variants.