An Italian team reports data from a series of 10 patients (seven men) with late-onset multiple acyl-CoA dehydrogenase deficiency (MADD), with no family history.
- Symptoms were very varied and began between the ages of 12 and 62 years, often abruptly or evolving rapidly: myalgia and discomfort when walking, fatigue, exercise intolerance, muscle weakness, difficulty in chewing, dysphonia, dysphagia.
- Two patients had upper limb weakness and two had head droop with more generalised muscle weakness; two others had an ataxic gait with numbness and paresthesia of the lower limbs.
- CPK levels ranged from 260 to 6500 IU/L.
- Serous concentrations of long- and medium-chain acylcarnitines were elevated at the time of diagnosis.
- The presence of lipid vacuoles on the muscle biopsy was systematic and the Western blot showed the absence of the electron transfer protein ubiquinone oxidoreductase or flavoprotein dehydrogenase (ETFDH) in 8 muscle biopsies and a strong decrease in the other two.
- Genetic analysis revealed 14 different ETFDH gene variants, five of which were previously undescribed.
- All patients responded to riboflavin treatment (400mg/day, except for the youngest who received 200mg/d) with complete resolution of symptoms and normalisation of blood parameters at 6 months, persisting for at least two years (up to 15 years for the longest follow-up).
