Disease Information for Succinic Semialdehyde dehydrogenase Deficiency

Clinical Manifestations
Signs & Symptoms
Awkward Uncoordinated Child
Behavior problems
Clumsiness/poor coordination
Delayed speech/language development
Development Motor Skills (Milestones) Delayed
Developmental milestones delayed
Hyporeflexia/DTRs decreased
Infant Seizures
Limb Ataxia
Limb ataxia/clumsiness child
Mental Deficiency Child
Psychomotor regression/infant/child
Seizures Newborn
Slow Motor Development
Weak reflexes
Destructive Behavior
True Vertigo Sign Confirmed
Demographics & Risk Factors
Population Group
Population/Pediatrics population
Sex & Age Groups
Laboratory Tests
Abnormal Lab Findings (Non Measured)
Gamma hydroxybutyrate levels present/increased
Succinic Semialdehyde levels increased
URINE/Gamma hydroxybutyrate levels
Abnormal Lab Findings - Increased
Ammonia blood (Lab)
Associated Diseases & Rule outs
Associated Disease & Complications
Mental retardation
Neurobehavior Problems
succinic semialdehyde dehydrogenase deficiency
Urea cycle/metabolic disorder
Disease Mechanism & Classification
Pathophysiology/Accumulation of 4-gamma hydroxy butyrate
Pathophysiology/Gene locus 6p22
Pathophysiology/Gene locus Chromosome 6p
Pathophysiology/Relative GABA CNS deficiency
Pathophysiology/GABA neurotransmitter metabolism defect
PROCESS/Autosomal recessive disorder (ex)
PROCESS/Genetic expressivity variable (ex)
PROCESS/Metabolic/storage disorder (category)
Succinic Semialdehyde dehydrogenase Deficiency, Synonym/4-Hydroxybutyric aciduria, Synonym/SSADH deficiency

Succinic Semialdehyde Dehydrogenase Deficiency; AKA: 4-Hydroxybutyric Aciduria; SSADH Deficiency; Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare inborn error of metabolism that is inherited as an autosomal recessive trait;In individuals with the disorder, deficient activity of the SSADH enzyme disrupts the metabolism of gamma-aminobutyric acid (GABA); GABA is a natural chemical known as a "neurotransmitter" that serves to inhibit the electrical activities of nerve cells (inhibitory neurotransmitter); SSADH deficiency leads to abnormal accumulation of the compound succinic semialdehyde, which is reduced or converted to 4-hydroxybutyric acid, also known as GHB (gamma-hydroxybutyric acid); GHB is a natural compound that has a wide range of effects within the nervous system; The "hallmark" laboratory finding associated with SSADH deficiency is elevated levels of GHB in the urine (i.e., 4-hydroxybutyric or gamma-hydroxybutyric aciduria), the liquid portion of the blood (plasma), and the fluid that flows through the brain and spinal canal (cerebrospinal fluid [CSF]); SSADH deficiency leads to various neurological and neuromuscular symptoms and findings; These abnormalities may be extremely variable from case to case, including among affected members of the same families (kindreds); However, most individuals with SSADH deficiency are affected by mild to severe mental retardation, delays in the acquisition of skills requiring the coordination of mental and physical activities (psychomotor retardation), and delays in language and speech development; In addition, in some cases, initial findings may include diminished muscle tone (hypotonia), an impaired ability to coordinate voluntary movements (ataxia), and/or episodes of uncontrolled electrical activity in the brain (seizures); Some affected individuals may also have additional abnormalities, such as decreased reflex reactions (hyporeflexia); involuntary, rapid, rhythmic eye movements (nystagmus); increased muscular activity (hyperkinesis); and/or behavioral abnormalities---------[NORD 2005]---------


External Links Related to Succinic Semialdehyde dehydrogenase Deficiency
PubMed (National Library of Medicine)
NGC (National Guideline Clearinghouse)
Medscape (eMedicine)
Harrison's Online (accessmedicine)
NEJM (The New England Journal of Medicine)