Cerebellar ataxia is a neurological condition that affects the cerebellum, the part of the brain that is responsible for coordinating movement and maintaining balance. There are multiple causes of cerebellar ataxia, but in some individuals this is due to a genetic condition (hereditary ataxia). There are multiple genes that have been associated with hereditary ataxias.

CA8-related cerebellar ataxia is an ultra-rare condition, reported in less than 10 families around the world to date (2023). It can cause difficulties with balance and coordination, challenges with speech and developmental delay or intellectual disability in some. An alternative name for this condition is ‘cerebellar ataxia, mental retardation and dysequilibrium syndrome 3’ (CAMRQ3)

CA8-related cerebellar ataxia is an ‘autosomal recessive’ condition. It is caused by a spelling mistake (mutation) in the CA8 gene. We each have two copies of this gene, and it is necessary that both copies of the gene have a mutation in order to have the condition. In most (but not all) cases, both parents carry a mutation in one copy of the gene but not the other, so do not have features of the condition but are at risk of having a child with the condition. A person with the condition typically inherits one mutation from the mother, and one from the father. When both parents are carriers of a CA8 mutation, the chances of having a child with CA8-related cerebellar ataxia are 1 in 4 (25%). This is called ‘autosomal recessive’ inheritance.