Attention deficit/hyperactivity disorder as an associated feature in OCTN2 deficiency with novel deletion (p.T440-Y449).

This boy presented with ADHD at 3 years and at 8 years was hyperactive with no documented hypoglycemia and had myopathy, cardiomyopathy, and very low serum carnitine. L-carnitine improved his exercise intolerance, cardiomyopathy, and behavior. Analysis of SLC22A5 revealed a premature stop codon (p.R282*) and a novel in-frame deletion (p.T440-Y449).