Long-term outcomes of a patient with late-onset multiple acyl-CoA dehydrogenase deficiency caused by novel mutations in ETFDH: A case report.

rationaleLate-onset multiple acyl-coenzyme A dehydrogenase deficiency (MADD) mainly affects the neck extensor muscle group, which has been confirmed by novel mutations in electron-transferring-flavoprotein dehydrogenase (ETFDH). So far, a few cases have been reported with long-term follow-up. Here we report a case of late-onset MADD where the patient was followed up for 8 years during which time he underwent 2 muscle biopsies and 2 pathological examinations and his symptoms were significantly alleviated after appropriate treatments. PATIENT CONCERNS: In September 2009, a 16-year-old male patient was hospitalized due to gradually increasing difficulty in raising his head and weakness in limb muscles over a 6-month period. During the physical examination, the patient's neck extensor muscle strength was grade III-IV. His proximal limb muscle strength was grade IV, and his distal muscle strength was normal. His blood creatine kinase (CK) was 783 U/L. DIAGNOSIS: Muscle biopsy revealed a large number of vacuolar fibers, which were mainly type I fibers. These findings were consistent with the diagnosis of lipid storage myopathy (LSM). ETFDH gene test detected C.736G > A at exon 7 and C.920C > G at exon 8.

interventionsCoenzyme Q10 treatment was administered. The first coenzyme Q10 40 mg tid was treated for three months, with the change of coenzyme Q10 20 mg tid for 6 months, followed by the change of coenzyme Q10 10 mg tid for long-term use. OUTCOMES: The patient's condition significantly improved after 3 months. At 7th year follow-up the patient's blood CK was normal, and a second muscle biopsy revealed no muscle vacuolar fibers and no increase in lipid droplets. Subsequently, the patient was withdrawn from the coenzyme Q10 treatment, and the condition of the patient remained normal. LESSONS: Muscle biopsy was the main method used to determine LSM. Treatment with riboflavin should be started when the diagnosis of LSM is definitive. Furthermore, ETFDH gene tests should be performed for further classification. Moreover, coenzyme Q10 may be another effective drug for MADD.