Hereditary ceruloplasmin deficiency with hemosiderosis: a clinicopathological study of a Japanese family

Ceruloplasmin gene expression in the murine central nervous system

Aceruloplasminemia is an autosomal recessive disorder resulting in neurodegeneration of the retina and basal ganglia in association with iron accumulation in these tissues. To begin to define the mechanisms of central nervous system iron accumulation and neuronal loss in this disease, cDNA clones encoding murine ceruloplasmin were isolated and characterized. RNA blot analysis using these clones detected a 3.7-kb ceruloplasmin-specific transcript in multiple murine tissues including the eye and several regions of the brain. In situ hybridization of systemic tissues revealed cell-specific ceruloplasmin gene expression in hepatocytes, the splenic reticuloendothelial system and the bronchiolar epithelium of the lung. In the central nervous system, abundant ceruloplasmin gene expression was detected in specific populations of astrocytes within the retina and the brain as well as the epithelium of the choroid plexus. Analysis of primary cell cultures confirmed that astrocytes expressed ceruloplasmin mRNA and biosynthetic studies revealed synthesis and secretion of ceruloplasmin by these cells. Taken together these results demonstrate abundant cell-specific ceruloplasmin expression within the central nervous system which may account for the unique clinical and pathologic findings observed in patients with aceruloplasminemia.

Hereditary ceruloplasmin deficiency with hemosiderosis

Hereditary ceruloplasmin deficiency with hemosiderosis (aceruloplasminemia) is a new disease characterized by systemic hemosiderosis, diabetes mellitus, neurological abnormalities and pigment degeneration of the retina. Loss of the ferroxidase activity of ceruloplasmin results in systemic iron deposition and tissue damage. Neuroimaging studies reveal iron deposition in basal ganglia and in the red and dentate nuclei. Cerebellar ataxia, extrapyramidal signs and dementia develop after middle age. We report a patient with undetectable serum ceruloplasmin levels and the above clinical manifestations. Sequence analysis of the cDNA of ceruloplasmin from this patient revealed an insertion of adenine in exon 3; this produced a premature stop codon.

Characterization of a nonsense mutation in the ceruloplasmin gene resulting in diabetes and neurodegenerative disease

We report here on the characterization of a mutation in the ceruloplasmin gene in a 45 year old woman with insulin-dependent diabetes mellitus who presented with the recent onset of gait disturbance and dysarthria. Physical examination revealed an ataxic gait, scanning speech and retinal degeneration. Magnetic resonance imaging of the brain was consistent with increased basal ganglia iron content and laboratory studies revealed a low serum iron concentration and no detectable serum ceruloplasmin. Nucleotide sequence analysis of the ceruloplasmin gene from this patient revealed a G to A substitution in exon 15 resulting in a nonsense mutation at amino acid 858 (Trp858ter). The patient's younger, neurologically asymptomatic brother was also found to be homozygous for this mutation. Taken together the clinical and genetic data support the concept of an essential and unique role for ceruloplasmin in human iron metabolism. Identification of this kindred extends the spectrum of ceruloplasmin gene mutations resulting in this autosomal recessive, late-onset neurodegenerative disease and highlights the importance of recognizing aceruloplasminemia as a genetic cause of diabetes and neurologic disease.