Recurrent myoglobinuria due to carnitine palmitoyltransferase II deficiency: clinical, biochemical, and genetic features of adult-onset cases.
OBJECTIVE
To create awareness of adult-onset carnitine palmitoyltransferase II (CPT II) deficiency by describing the clinical, biochemical, and genetic features of three New Zealand patients with this disorder.


METHODS
Review of case notes, creatine kinase (CK) values, CPT II assay results, genetic mutation analyses, and the literature.


RESULTS
Three patients with CPT II deficiency were encountered by the authors over a 7-year period. Onset of symptoms was between ages 10 and 17 years. Each patient reported exertional myalgia, and had had at least two episodes of myoglobinuria following exertion or infection. Interictal neurological examinations, CK values, and routine muscle histology were normal. CPT II activities ranged from 3.8 to 9.7 pmol/min/mg protein (normal+/-SD=162.9+/-51.0 pmol/min/mg protein). Genetic analysis showed that one patient was homozygous and two were heterozygous for S113L, the common mutation in CPT II deficiency.


CONCLUSIONS
CPT II deficiency should be suspected in patients with persistent exertional myalgia who have one or more episodes of myoglobinuria. The diagnosis is confirmed using a combination of enzyme assay and genetic testing.
Kilfoyle
Dean
D
Department of Neurology, Auckland Hospital, Auckland, New Zealand.
Hutchinson
David
D
Potter
Howard
H
George
Peter
P
D058186:Acute Kidney Injury / Q000209:etiology; D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002334:Carnitine O-Palmitoyltransferase / Q000172:deficiency*; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006801:Humans; D008052:Lipid Metabolism, Inborn Errors / Q000150:complications* / Q000235:genetics; D008297:Male; D009212:Myoglobinuria / Q000209:etiology*; D012008:Recurrence; D017422:Sequence Analysis, DNA
D005227:Fatty Acids; D002334:Carnitine O-Palmitoyltransferase