[Succinic semialdehyde dehydrogenase deficiency: an inheritable neurometabolic disease]

Abstract

Succinic semialdehyde dehydrognase deficiency (SSADHD) is a neurometabolic disease with autosomal recessive inheritance. Although only about 450 cases are known worldwide, SSADHD is a frequent paediatric disorder of the neurotransmitter metabolism. SSADHD is caused by a mutation of the Aldh5a1-gene resulting in a dysfunction of the enzyme succinic semialdehyde dehydrogenase. This is followed by an accumulation of γ-aminobutyric acid and succinic semialdehyde that is alternatively metabolised via succinic semialdehyde reductase to γ-hydroxybutyric acid. The clinical phenotype is unspecific with pronounced interindividual variability. However, delayed acquisition of motor and language developmental milestones as well as epilepsy, mental retardation, sleep disorder, ataxia, muscle hypotonia, and behavioural disturbances are frequent. First symptoms frequently occur in the first year of life while the general course of the disease is non-progressive. Currently, no causal therapy exists.