<unk>  is synthesized primarily in the liver and kidneys via a two-step enzymatic process. Defects in either of these two enzymes can cause a CCD. In order to pass the blood brain barrier,<unk>  requires a specialized transporter, encoded for by SLC6A8. A defect in this transporter is responsible for the third CCD.
Cerebral creatine deficiency
Pantothenate kinase-associated neurodegeneration
Creatine transporter defect
N-Acetylglutamate synthase deficiency
Dopamine beta hydroxylase deficiency
Systemic primary carnitine deficiency
Mitochondrial encephalomyopathy
Mitochondrial toxicity