We identified a mutation in the ceruloplasmin (Cp) gene in a Japanese family with aceruloplasminemia, some of whose members showed extrapyramidal disorders, cerebellar ataxia, and diabetes mellitus. A post-mortem study of the proband revealed excessive iron deposition mainly in the brain, liver and pancreas. The G to A transition at the splice acceptor site introduces a premature termination codon at the amino acid position 991 by defective splicing, thereby truncating the carboxyl terminus of Cp in affected individuals. We conclude that the mutation in the Cp gene is associated with systemic hemosiderosis in humans.

A hereditary ceruloplasmin deficiency associated with severe iron deposition in visceral organ and brain tissues found on histopathological examination at autopsy is discussed. Three siblings of consanguineous Japanese parents were studied. Their clinical symptoms were progressive dementia, extrapyramidal disorders, cerebellar ataxia, and diabetes mellitus, all of which appeared when they were between 30 and 50 years old. All had serum ceruloplasmin deficiencies and increased serum ferritin concentrations. The dentate nucleus, thalamus, putamen, caudate nucleus, and liver of each one showed low signal intensities on T1- and T2-weighted magnetic resonance images. Examination of the central nervous system revealed severe destruction of the basal ganglia and dentate nucleus, with considerable iron deposition in neuronal and glial cells, whereas the cerebral cortex showed mild iron deposition in glial cells without neuronal involvement. An electron microscopic study with energy-dispersive x-ray analysis showed iron depositions in the hepatocytes, of both the neural and glial cells of the brain. We consider this a new disease entity because of the primary ceruloplasmin deficiency.

Aceruloplasminemia is an autosomal recessive disorder caused by mutations in the ceruloplasmin (CP) gene, and is characterized by a unique combination of neurovisceral iron overload and iron deficiency anemia. We generated CP-deficient (CP(-/-)) mice to investigate the functional involvement of CP in iron metabolism. The mice showed a marked iron overload in the liver and mild iron deficiency anemia. We examined the expression of iron-metabolism genes in the duodenum and liver using TaqMan RT-PCR. The divalent metal transporter 1 (DMT1), ferroportin 1 (FPN1), and hephaestin (HEPH) genes were not up-regulated in the duodenum from CP(-/-) mice. These data suggest that the mechanism of hepatic iron overload in aceruloplasminemia is quite different from that in hemochromatoses and atransferrinemia. In the liver, CP(-/-) mice showed no increase of gene expression for DMT1 and transferrin receptors (TFR and TFR2), indicating that none of the known pathways of iron uptake is activated in hepatocytes of CP(-/-) mice. This result supports the hypothesis that CP mainly acts to release iron from cells in the liver.

A series of truncated dystrophin cDNAs (3.1^4.2 kbp) containing only three, three, two or one rod repeats with hinge 1 and 4 (named v vDysAX2, AX11, AH3, M3, respectively) or no rod repeat retaining either hinge 1 or 4 (named v vDysH1, H4, respectively) were constructed. These cDNAs were introduced into skeletal muscle of adult mdx mice using the adenovirus vector with a strong CAG promoter. v vDysAX2, AX11, AH3 and v vDysM3 expressed themselves successfully and recovered dystrophin-associated proteins effectively. Especially 3.7 kbp cDNA for v vDysM3 offers the possibility of an approach utilizing newly developed virus vectors, such as an adeno-associated virus vector, toward gene therapy of Duchenne muscular dystrophy.z 1998 Federation of European Biochemical Societies.