Succinic semialdehyde dehydrogenase deficiency (SSADHD)

In the breed Saluki, a genetic variant has been found to be associated with a neurometabolic disease called Succinic semialdehyde dehydrogenase deficiency (SSADHD). SSADHD is caused by an enzyme deficiency that impairs the metabolism of gamma-aminobutric acic (GABA), which is an important neurotransmitter of the central nervous system. Affected puppies usually show first signs of the disease at the age of 6-10 weeks. Typical symptoms are neurological abnormalities, seizures and change in behaviour. Owners of affected puppies reported that their dogs show episodes of vocalization, a mild generalized ataxia and also lethargy, so that owners often have difficulties to wake up the puppies. Further abnormalities are absent menace reflexes in both eyes, thoracic limb hypermetria and delayed proprioceptive positioning in all four limbs. Elevated concentrations of gamma-hydroxybutyric (GHB) acid could be found in serum, while the concentrations of succinic semialdehyde (SSA) are elevated in urine. Because of the severe symptoms, affected puppies are often euthanized at the age of 3-9 months.