Carnitine palmitoyl transferase II polymorphism is associated with multiple syndromes of acute encephalopathy with various infectious diseases.

The high incidence of acute encephalopathy in East Asia suggests the role of genetic factors in its pathogenesis. It has recently been reported that variations of the CPT II (carnitine palmitoyl transferase II) gene may be associated with fatal or severe cases of influenza-associated encephalopathy. In the present study, we examined the genotype of CPT II in cases of acute encephalopathy associated with various preceding infections. Twenty-nine Japanese patients with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) or acute necrotizing encephalopathy (ANE) were studied. The frequency of F352C of CPT II exon 4 was significantly higher in patients than in controls. All patients who had allele C in F352C had allele I in V368I and allele M in M647V (CIM haplotype), which reportedly decreases CPT II activity to one third of that with FIM or FVM haplotype. The frequency of CIM haplotype was significantly different between patients and controls, but not between AESD and ANE. Our results revealed that having at least one CIM allele is a risk factor for the onset of acute encephalopathy, regardless of its antecedent infections.