Letter: Copper and steely hair

Menkes disease: an X-linked neurological disorder of the copper metabolism

Menkes disease is an X-linked, recessive disturbance of copper metabolism associated with a progressive clinical course and abnormal hair. The disease is dominated by neurological symptoms combined with connective tissue manifestations, most of which can be explained by the lack of important copper enzymes. Despite excessive accumulation of the metal in various tissues, a functional copper deficiency is evident, probably caused by a defective intracellular copper transport protein of unknown nature. The molecular basis of the copper disturbance has proven difficult to define and will most likely have to await cloning of the gene. The chromosomal region of interest has now been narrowed down to a sub-band on the long arm of the chromosome (Xq13.3), and positional cloning is in progress in a number of laboratories including our own. Identification of the Menkes gene will be of importance for our understanding of the cellular handling of copper and other trace elements.

Genetic expression of Menkes disease in cultured astrocytes of the macular mouse

The copper concentration was investigated in the cultured astrocytes from macular mice, an animal model of Menkes disease. An excessive amount of copper was accumulated in the astrocytes as copper-metallothionein. These results show that the underlying genetic defect of the macular mouse is expressed in the astrocytes. A similar situation may exist in Menkes disease and cause a failure of copper transport to neurones.

Difficulties in the neonatal diagnosis of Menkes' kinky hair syndrome--trichopoliodystrophy

The recognition of Menkes' kinky hair syndrome, trichopoliodystrophy, may present problems in the early neonatal period. The serum copper, and ceruloplasmin levels are within the range of normal infants in the first week of life; they are higher than normal in the cord blood of affected infants and fall gradually. Pili torti may only develop later, as the primary fetal hair is normal. The baby may appear bald, or both normal and abnormal hair may be found in different areas of the skull. The roentgenographic signs of wormian bones in the skull, metaphyseal spurring of the long bones, and diverticuli of the bladder develop progressively and may not be seen until after 6 weeks of age. However, diagnosis is possible in the neonatal period, if male infants with unexplained hypothermia, hypotonia, septicemia, or seizures are investigated by serum copper and ceruloplasmin levels after 1 month of age.

[Menkes syndrome: review of the pathogenesis apropos of a clinico-pathological case]

The authors report a case of Menkes' syndrome, probably the first one described in Brazil. The patient, a 15-month-old boy, showed pili torti, early progressive psychomotor deterioration and seizures. Serum levels of ceruloplasmin and copper were very low. Neuroradiological and roentgenological examinations revealed diffuse cerebral atrophy, arterial changes and bone abnormalities. At the post-mortem examination the more consistent findings were cerebral atrophy, neuronal loss in the thalamus and above all cerebellar cortical lesions. The disease has a sex-linked recessive inheritance and is believed to be caused by an inborn error of copper metabolism, perhaps subordinated to changes of proteins which carry copper to different tissues. The relevant literature in relation to the pathogenesis is reviewed.

Cadmium, zinc, and copper metabolism in the mottled mouse, an animal model for Menkes' kinky hair syndrome

Studies of uptake and release of 64Cu, 109Cd, and 65Zn in suckling C57BL/6J male mice revealed kinetics and distributions that differed for each metal both within and among the organs analyzed, suggesting distinct, albeit overlapping, mechanisms for transport and binding of each metal. In mutants, there were tissue-specific increases in copper-binding capacity. In hemizygotes (Moblo/y) accumulation of 64Cu was increased in kidney, lung, and duodenum. In heterozygotes (Moblo/+), 64Cu content was increased in kidney, with a smaller increase in lung, and no change in duodenal Cu. Decreased 64Cu accumulation was seen in liver in both hemi- and heterozygotes. In contrast, 64Zn and 109Cd accumulation in organs of heterozygote mice was not significantly distinguishable from normal. In skin and connective tissues there is excessive accumulation of 64Cu in Moblo/+ and Moblo/y, no abnormality in heterozygote 65Zn accumulation, but a clear decrease in heterozygote 109Cd content. In both mutant kidney and liver, there was an aberrant subcellular distribution of 64Cu, with the major fraction of sequestered 64Cu in the cytosol. Our studies establish that in spite of the ubiquity of metallothioneins and the structural similarities of those that have been characterized, there is specificity and functional heterogeneity in metal binding among tissues. The aggregate data suggest that there are unique regulatory mechanisms for the metabolism of copper and zinc, while there exists, in part, an inverse relationship between the binding of copper and cadmium. Our data further suggest that the blotchy mutation involves a specific cytosolic copper storage or transport protein also capable of binding cadmium.

Menkes' syndrome: an updated review

Menkes' syndrome is an X-linked recessive multisystem disease which is usually fatal prior to 5 years of age. Though originally felt to be a disorder of copper deficiency, it now appears to be a copper storage disease, with the observed defects resulting from inappropriate systemic copper distribution. Disorders in the metabolism of metallothionein, a metalloprotein involved in cellular copper transport, may be the primary defect in this syndrome. This review summarizes the relevant clinical and pathologic findings seen in this condition to date. It also describes some of the abnormalities in the metabolism of copper and metallothionein in these infants.

Synthesis of a metallothionein-like protein in cultured human skin fibroblasts: relation to abnormal copper distribution in Menkes' disease

A metallothionein-like protein (MTP) is synthesized in normal diploid human skin fibroblasts cultured in Zn- or Cu-supplemented medium. Synthesis of MTP is not detected in cells cultured without metal supplementation of complete tissue-culture medium. Cultured fibroblasts from patients with Menkes' disease accumulate excess Cu which chromatographs both with high-molecular-weight protein(s) and with a Cu-MTP. Under normal culture conditions, the Menkes' MTP incorporates [35S]-cystine, but not appreciable amounts of 65Zn. However, Menkes fibroblasts retain the ability to incorporate 65Zn into MTP in response to Zn supplementation of the medium. The results do not support the idea that Menkes' disease results from a failure of Cu to bind to MTP, but rather that an elevated intracellular Cu concentration in Menkes' disease fibroblasts leads to association of excess Cu with high-molecular-weight protein, stimulating synthesis of a Cu-binding MTP.

Clinical and biochemical aspects of trichopoliodystrophy

The clinical and biochemical evaluation of 6 patients with trichopoliodystrophy indicates that the disease process can begin in utero and is related to a selective abnormality in copper metabolism. Examination of 2 infants on the first day of life revealed abnormal neurological signs, a characteristic hair abnormality, and elevated levels of copper and ceruloplasmin. Decreased hepatic copper levels and increased urinary copper excretion were documented during the first week. The 2 neonates demonstrated a progressive decrease in blood copper levels in the first month of life. Four infants identified at ages 2 to 11 months had low values for blood copper and ceruloplasmin. All infants had progressive neurological dysfunction, and 4 of the 6 died at ages ranging from 2 1/2 months to 5 1/2 years. Parenteral copper therapy achieved normal blood and hepatic copper levels in 1 patient, but the copper values in the cerebral cortex and white matter were significantly decreased compared to control specimens.

Copper incorporation studies on cultured cells for prenatal diagnosis of Menkes' disease

The incorporation of 64Cu into cultured fibroblasts from 7 boys with Menkes' steely hair disease and from 9 controls was examined. The median 20 h incorporation was 74-4 ng 64Cu/mg protein for the patients and 26-1 ng 64Cu/mg protein for the controls (P less than 0.01). Thus, the defect in copper metabolism in the disease was expressed in cultured cells. The method was applied to amniotic fluid cell-cultures of 2 pregnancies at risk and to amniotic fluid cell-cultures with a male karyotype of 8 normal pregnancies. The median 20h 64Cu incorporation into the normal cell-cultures was 19.2 ng 64Cu/mg protein, into the cell-culture from one pregnancy at risk was 48-6 ng 64Cu/mg protein, and from the other, 12-5 ng 64Cu/mg protein. The first case was aborted and the copper distribution in the fetus was found to be abnormal--consistent with Menkes' disease. The second case at risk was born in May, 1975, and no signs of Menkes' disease have developed. These cases demonstrate that prenatal diagnosis of Menkes' steely hair disease might be feasible.

Menkes's steely hair syndrome

Three unrelated cases of Menkes's syndrome are described. In addition to the typical features these cases all showed abnormalities of the urinary tract characterized by hydronephrosis, hydroureter, and bladder diverticula. There was no organic obstruction in the urinary tract and the changes are presumed to be due to disturbed innervation. The 3 patients showed no overall clinical response to parenteral copper therapy administered for periods of 1 to 8 months. Necropsy studies showed structural changes in veins as well as arteries together with aneurysm formation in both, and one case showed a polypoid lesion in the stomach.