In Group B 10/16 patients had a metabolic disorder (3/9 with Menkes disease), 3/16 a sodium or potassium channelopathy (SCN1A, KCNQ2, KCND3), 2/16 Rett syndrome, and 1/16 a synaptopathy (Table 2). This evidence concerns the gene KCND3 and metabolic disease.