title: Glutaric aciduria type 1 in South Africa-high incidence of glutaryl-CoA dehydrogenase deficiency in black South Africans.
abstract: Glutaric Aciduria type 1 (GA 1) is an inherited disorder of lysine and tryptophan catabolism that typically manifests in infants with acute cerebral injury associated with intercurrent illness. We investigated the clinical, biochemical and molecular features in 14 known GA 1 patients in South Africa, most of whom were recently confirmed following the implementation of sensitive urine organic acid screening at our laboratory. Age at diagnosis ranged from 3days to 5years and poor clinical outcome reflected the delay in diagnosis in all but one patient. Twelve patients were unrelated black South Africans of whom all those tested (n=11) were found homozygous for the same A293T mutation in the glutaryl-CoA dehydrogenase (GCDH) gene. Excretion of 3-hydroxyglutarate (3-OHGA) was >30.1μmol/mmol creatinine (reference range <2.5) in all cases but glutarate excretion varied with 5 patients considered low excretors (glutarate <50μmol/mmol creatinine). Fibroblast GCDH activity was very low or absent in all of five cases tested. Heterozygosity for the A293T mutation was found 1 in 36 (95% CI; 1/54 - 1/24) unrelated black South African newborns (n=750) giving a predicted prevalence rate for GA 1 of 1 in 5184 (95% CI; 1/11664 - 1/2304) in this population. GA 1 is a treatable but often missed inherited disorder with a previously unrecognised high carrier frequency of a single mutation in the South African black population.
authors: Division of Chemical Pathology, Groote Schuur and Red Cross Children's Hospitals, University of Cape Town, Cape Town, South Africa. george.vanderwatt@uct.ac.za
authors: George
authors: G
authors: van der Watt
authors: Elizabeth P
authors: EP
authors: Owen
authors: Peter
authors: P
authors: Berman
authors: Surita
authors: S
authors: Meldau
authors: Nicholas
authors: N
authors: Watermeyer
authors: Simon E
authors: SE
authors: Olpin
authors: Nigel J
authors: NJ
authors: Manning
authors: Ingrid
authors: I
authors: Baumgarten
authors: Felicity
authors: F
authors: Leisegang
authors: Howard
authors: H
authors: Henderson
mesh_terms: D000592:Amino Acid Metabolism, Inborn Errors / Q000453:epidemiology / Q000235:genetics; D044383:Black People / Q000235:genetics; D001928:Brain Diseases, Metabolic / Q000453:epidemiology / Q000235:genetics; D002675:Child, Preschool; D005260:Female; D050770:Glutaryl-CoA Dehydrogenase / Q000172:deficiency* / Q000235:genetics; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013019:South Africa / Q000453:epidemiology
chemical_list: D050770:Glutaryl-CoA Dehydrogenase