RESUMO
We investigated fatty alcohol metabolism in eight patients with Sjögren-Larsson syndrome, and in nine obligate heterozygotes. Fatty alcohol: nicotinamide-adenine dinucleotide oxidoreductase (FAO) activity was deficient in cultured skin fibroblasts (mean 18% of normal, n = 8) and peripheral blood leukocytes (mean 22% of normal, n = 3) from patients with Sjögren-Larsson syndrome. The palmitoyl coenzyme A-inhibitable component of FAO activity was decreased to 10% and 15% of normal in fibroblasts and leukocytes, respectively, of patients with Sjögren-Larsson syndrome. Most affected patients accumulated long-chain fatty alcohol in plasma, with a greater relative accumulation of octadecanol (mean threefold greater than normal) than hexadecanol (mean twofold greater than normal). Erythrocyte lipid alkyl ether linkages derived from hexadecanol were slightly increased in three of four patients. Fibroblasts and leukocytes from heterozygotes with Sjögren-Larsson syndrome showed mean FAO activities that were intermediate between those seen in homozygotes and in normal control subjects. The heterozygotes had normal fatty alcohol concentrations in plasma. These studies demonstrate FAO deficiency in patients with Sjögren-Larsson syndrome, and suggest that accumulation of fatty alcohol or its metabolic products may be important in the pathogenesis of this disorder.
Assuntos
Oxirredutases do Álcool/deficiência , Álcoois Graxos/metabolismo , Ictiose/genética , Erros Inatos do Metabolismo/genética , Adolescente , Pré-Escolar , Eritrócitos/metabolismo , Éteres/sangue , Feminino , Fibroblastos/enzimologia , Humanos , Ictiose/enzimologia , Leucócitos/enzimologia , Masculino , Erros Inatos do Metabolismo/enzimologiaRESUMO
Two patients with neonatal seizures and subsequent normal neurological development were found to have nonketotic hyperglycinemia. In both patients, hyperglycinemia resolved at 6 weeks of age. After cerebrospinal fluid glycine levels were normalized, the seizures stopped completely in one child and were markedly improved in the other. The possible mechanisms for the hyperglycinemia are discussed.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/genética , Genes Recessivos , Glicina/sangue , Espasmos Infantis/genética , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Glicemia/metabolismo , Feminino , Seguimentos , Humanos , Recém-Nascido , MasculinoRESUMO
Secondary carnitine deficiency in a patient with glutaric acidaemia type II, due to deficient ETF-dehydrogenase activity, is described. The patient responded clinically to a pharmacological dose of riboflavin and a restricted protein diet. In the second year of her life she developed more frequent and severe exacerbations during intercurrent infections from which she did not fully recover. Hypotonia and marked ataxia persisted. Plasma carnitine was entirely complexed as acylcarnitine with no free carnitine detected. Retrospective evaluation of several frozen urine specimens obtained since the age of 10 months revealed undetectable free carnitine with elevated acylcarnitine levels. Marked clinical improvement was observed following L-carnitine supplementation. The hypotonia and ataxia disappeared. The frequency and the severity of the exacerbations were noticeably decreased. The role of L-carnitine in preventing the accumulation of acyl-CoA compounds in inborn errors of organic acid metabolism is further emphasized by this patient. The necessity to evaluate free carnitine, acylcarnitine and acyl/free ratio in the assessment, follow-up and management of patients with inborn errors of organic acid metabolism is discussed.
