Genetic (inherited) causes of dementia are rare, but can be identified in some people with young-onset dementia and/or a family history compatible with a monogenic cause.

Genomic (inherited) causes of dementia are rare, but can be identified in those with a young onset and/or a family history.

Monogenic causes account for up to 20% of frontotemporal dementia presentations and so genomic testing should be carefully considered for anyone diagnosed with the condition.

At least 2.5% of patients with schizophrenia carry an identifiable neurodevelopmental copy number variant. This is likely to be more prevalent in patients with intellectual disability, neurodevelopmental conditions, congenital anomalies and/or a positive family history.

In some patients who present with Parkinson disease at a young age, with or without a family history, there will be an underlying genetic cause.

Some cases of young-onset motor neurone disease (also known as amyotrophic lateral sclerosis (ALS)) will have a genetic cause.

Genetic causes of dementia are rare, and are typically associated with early disease onset and/or complex neurological symptoms. There is often a significant family history.

Spinal and bulbar muscular atrophy, also known as Kennedy disease, is a genetic cause of progressive limb and bulbar weakness.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy is a rare cause of vascular stroke and cognitive impairment.

Genomic testing should be considered in all adults with unexplained leukodystrophy on neuroimaging, with or without a family history.