[Late-onset riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency (glutaric aciduria type II)].
OBJECTIVE
Glutaric aciduria type II, or multiple acyl-CoA dehydrogenase deficiency is an autosomal recessively inherited defect of mitochondrial energy metabolism. The authors report two cases of late-onset glutaric aciduria type II, and evaluate the procedures for the diagnosis and treatment of this rare disease.


METHODS
The clinical and biochemical characteristics of 2 patients with late-onset glutaric aciduria type II were documented. Case 1 presented with lipid storage myopathy for 3 years. Case 2 presented with intermittent episodes of non-ketotic hypoglycemia and muscle weakness for 9 years. The diagnosis of the 2 cases was confirmed with gas chromatography/mass spectrometry analysis of urine samples. Riboflavin supplementation and a low-fat, low-protein, high-carbohydrate diet were initiated as soon as the diagnosis was made.


RESULTS
Organic acid analysis on both untreated cases revealed massive glutaric acid with elevated concentrations of isovalerylglycine, isobutyrylglycine, ethylmalonic acid, adipic acid, suberic acid and other dicarboxylic acids. The clinical manifestations were improved remarkably after the administration of riboflavin and diet control. Consistent improvements of sera enzymes and urine organic acids were observed during the course of treatment.


CONCLUSIONS
Patients with unexplained myopathy, metabolic acidosis or hypoglycemia should be carefully screened for inherited metabolic disorders. Riboflavin in conjunction with appropriate diet control is an effective therapeutic regime for patients with late-onset glutaric aciduria type II.
Liang
Yan
Y
Department of Pediatrics, Tongji Hospital, Center for the Diagnosis of Genetic Metabolic Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Liu
Li
L
Wei
Hong
H
Luo
Xiao-ping
XP
Wang
Mu-ti
MT
D042964:Acyl-CoA Dehydrogenase / Q000172:deficiency*; D000293:Adolescent; D017668:Age of Onset; D002648:Child; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D005977:Glutarates / Q000652:urine; D006801:Humans; D008661:Metabolism, Inborn Errors / Q000175:diagnosis / Q000188:drug therapy* / Q000652:urine; D017319:Photosensitizing Agents / Q000627:therapeutic use; D012256:Riboflavin / Q000627:therapeutic use*; D016896:Treatment Outcome
D005977:Glutarates; D017319:Photosensitizing Agents; D042964:Acyl-CoA Dehydrogenase; C035736:glutaric acid; D012256:Riboflavin