The symptoms of<unk>  fall into three primary categories: neurological, psychiatric, and ocular. The most constant features seen are developmental delay, hypotonia and intellectual disability. Nearly half of patients seen manifest ataxia, behavior problems, seizures, and hyporeflexia. The age of onset ranges from newborn period to 25 years. Problems unique to neonates can include prematurity, lethargy, decreased sucking, respiratory difficulty and hypoglycemia. Gastrointestinal symptoms have been seen primarily in this population and are usually related to increased feeding. Ocular problems related to the disorder include strabismus, nystagmus, retinitis, disc pallor, and oculomotor apraxia. Over half of the patients with<unk>  have seizures. These include absence, tonic clonic, and convulsive status epilepticus. It is unclear whether decreased levels of GABA or elevated levels of GHB are responsible for these seizures but alterations in these neurotransmitters and their receptor binding or neurotransmitter transport is hypothesized to play a role in the pathogenesis of the seizures in this population. Symptoms associated with SSADHD may be mild, moderate or severe and often vary greatly from case to case. The symptoms of SSADH are caused by the accumulation of GHB in the brain and include the following manifestations (Defined as: common, > 70% of patients; frequent 30-70% of patients;unusual, < 30% of patients): Common manifestations include: * Delayed gross motor development * Delayed mental development * Delayed fine motor skill development * Delayed speech and language development * Hypotonia Frequent manifestations include: * Seizures * Hyporeflexia * Ataxia * Behavioral problems * Hyperkinesis Unusual manifestations include: * Neonatal problems * EEG abnormalities * Psychoses * MRI or X-ray computed tomography abnormalities * Oculomotor apraxia * Microcephaly * Macrocephaly * Hyperreflexia * Somnolence * Choreoathetosis * Myopathy
Succinic semialdehyde dehydrogenase deficiency
Pyruvate dehydrogenase deficiency
2-Methylbutyryl-CoA dehydrogenase deficiency
3-Methylcrotonyl-CoA carboxylase deficiency
Malonyl-CoA decarboxylase deficiency
Glutaminase deficiency
Pyruvate kinase deficiency
Succinyl-CoA:3-oxoacid CoA transferase deficiency