sodium-oxybate and Intellectual-Disability

Succinic semialdehyde dehydrogenase (SSADH) deficiency (gamma-hydroxybutyric aciduria) is a rare neurometabolic disorder of gamma-aminobutyric acid degradation. While neurological manifestations, such as developmental delay, are typical during infancy, limited data are available on adolescent and adult symptomatology.. We overview the phenotype of 33 adolescents and adults (10.1-39.5 years of age, mean: 17.1 years, 48% females) with SSADH deficiency. For this purpose, we applied a database with systematic questionnaire-based follow-up data.. Sixty-six percent of patients (n=21) presented by 6 months of age, 14% from 6-12 months of age, 5% from 1-2 years of age, and 14% from 2-4 years of age, mean age at first symptoms was 11+/-12 months. However, mean age at diagnosis was 6.6+/-6.4 years of age. Presenting symptoms encompassed motor delay, hypotonia, speech delay, autistic features, seizures, and ataxia. Eighty-two percent demonstrated behavioral problems, such as attention deficit, hyperactivity, anxiety, or aggression, and 33% had >or=3 behavior problems. Electroencephalograms showed background slowing or epileptiform discharges in 40% of patients. Treatment approaches are then summarized.. The variable phenotype in SSADH deficiency suggests the likelihood that this disease may be under-diagnosed. Families of patients with SSADH deficiency should be counseled and supported regarding the anticipated persistence of various neuropsychiatric symptoms into adulthood.

Topics: Adolescent; Adult; Amino Acid Metabolism, Inborn Errors; Ataxia; Behavioral Symptoms; Child; Child, Preschool; Cohort Studies; Developmental Disabilities; Electroencephalography; Female; Follow-Up Studies; gamma-Aminobutyric Acid; Humans; Intellectual Disability; Language Development Disorders; Male; Seizures; Sleep Wake Disorders; Sodium Oxybate; Succinate-Semialdehyde Dehydrogenase; Surveys and Questionnaires

We report two adult patients with succinic semialdehyde dehydrogenase deficiency, manifesting as gamma-hydroxybutyric aciduria. For both, the clinical presentation included significant behavioral disturbances and psychosis (hallucinations, disabling anxiety, aggressive behavior, and sleep disorder), leading to multiple therapeutic attempts. Intervention with benzodiazepines appeared most efficacious, resulting in decreased aggression and agitation and improvement in anxiety. A review of 56 published and unpublished studies of SSADH-deficient patients revealed that 42% manifested behavioral disturbances, whereas 13% (predominantly adults) displayed psychotic symptomatology. To explore the potential biochemical basis of these behavioral abnormalities, we studied cerebrospinal fluid derived from 13 patients, which revealed significantly elevated GHB (65- to 230-fold), high free and total GABA (up to threefold), and low glutamine. Although within the control range, homovanillic and 5-hydroxyindoleacetic acids (end products of dopamine and serotonin metabolism, respectively) showed a significant linear correlation with increasing GHB concentration, suggesting enhanced dopamine and serotonin turnover. We conclude that elevated GABA combined with low glutamine suggest disruption of the glial-neuronal glutamine/GABA/glutamate shuttle necessary for replenishment of neuronal neurotransmitters, whereas altered dopamine and serotonin metabolism may be causally linked to the hyperkinetic movement disorders and behavioral disturbances seen in SSADH-deficient patients.

Topics: Adult; Aldehyde Oxidoreductases; Atrophy; Cerebellum; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; Female; gamma-Aminobutyric Acid; Globus Pallidus; Glutamic Acid; Hallucinations; Homovanillic Acid; Humans; Hydroxyindoleacetic Acid; Intellectual Disability; Magnetic Resonance Imaging; Male; Metabolism, Inborn Errors; Sodium Oxybate; Statistics as Topic; Succinate-Semialdehyde Dehydrogenase

To further define the clinical spectrum of the disease for pediatric and metabolic specialists, and to suggest that the general pediatrician and pediatric neurologist consider succinic semialdehyde dehydrogenase (SSADH) deficiency in the differential diagnosis of patients with (idiopathic) mental retardation and emphasize the need for accurate, quantitative organic acid analysis in such patients.. The clinical features of 23 patients (20 families) with SSADH deficiency (4-hydroxybutyric acid-uria) are presented. The age at diagnosis ranged from 3 months to 25 years in the 11 male and 12 female patients; consanguinity was noted in 39% of families.. The following abnormalities were observed (frequency in 23 patients): motor delay, including fine-motor skills, 78%; language delay, 78%; hypotonia, 74%; mental delay, 74%; seizures, 48%; decreased or absent reflexes, 39%; ataxia, 30%; behavioral problems, 30%; hyperkinesis, 30%; neonatal problems, 26%; and electroencephalographic abnormalities, 26%. Associated findings included psychoses, cranial magnetic resonance or computed tomographic abnormalities, and ocular problems in 22% or less of patients. Therapy with vigabatrin proved beneficial to varying degrees in 35% of the patients. Normal early development was noted in 30% of patients.. Our data imply that two groups of patients with SSADH deficiency exist, differentiated by the course of early development. Our recommendation would be that accurate, quantitative organic acid analysis in an appropriate specialist laboratory be requested for any patients presenting with two or more features of mental, motor, or language delay and hypotonia of unknown cause. Such analyses are the only definitive way to diagnose SSADH deficiency; the diagnosis can be confirmed by determination of enzyme activity in white cells from whole blood. We think that increased use of organic acid determination will lead to increased diagnosis of SSADH deficiency and a more accurate representation of disease frequency. As additional patients are identified, we should have a better understanding of both the metabolic and clinical profiles of SSADH deficiency.

Topics: Adolescent; Adult; Aldehyde Oxidoreductases; Child; Child, Preschool; Developmental Disabilities; Diagnosis, Differential; Enzyme Inhibitors; Female; gamma-Aminobutyric Acid; Humans; Infant; Intellectual Disability; Language Development Disorders; Male; Metabolism, Inborn Errors; Motor Skills; Sodium Oxybate; Succinate-Semialdehyde Dehydrogenase; Vigabatrin

Topics: Adolescent; Aldehyde Oxidoreductases; Child; Family; Female; Humans; Intellectual Disability; Leukocytes; Male; Metabolism, Inborn Errors; New Caledonia; Sodium Oxybate; Succinate-Semialdehyde Dehydrogenase

A child presenting with mild psychomotor retardation, hypotonia, microcephaly and hyperkinesis is described. Urinary organic acid analysis by combined gas chromatography-mass spectrometry revealed 4-hydroxybutyric aciduria. Succinic semialdehyde dehydrogenase activity in extracts of white cells derived from the patient was less than 10% of control values.

Topics: Ataxia; Child; Female; Humans; Hydroxybutyrates; Hyperkinesis; Intellectual Disability; Muscle Hypotonia; Seizures; Sodium Oxybate