Andermann Syndrome (SLC12A6)
Andermann syndrome is an autosomal recessive disease caused by pathogenic variants in the gene SLC12A6. Pathogenic SLC12A6 variants may be found in people of any ethnicity, but are most common in people of French-Canadian ancestry due to the presence of a founder mutation in this population. Andermann syndrome affects the brain and nervous system. Symptoms begin in infancy and include low muscle tone and weakness, mild to moderate intellectual disability, and psychotic episodes in about 40% of affected people. Affected individuals are usually wheelchair-bound in their early teenage years. Life expectancy is in the early 30s. It is not possible to predict disease severity from the type of pathogenic variants inherited, because almost all individuals with Andermann syndrome have had the same French-Canadian variant.
For information about carrier frequency and residual risk, please see the residual risk table.