Experience with first trimester prenatal diagnosis of Menkes disease

We have performed 28 first trimester diagnoses for Menkes disease in 27 high risk pregnancies by direct copper measurement on chorionic villi (c.v.) Two male fetuses were found to be affected because of significantly increased copper content. In one male fetus a slightly increased copper content was observed indicating an exogenous copper contamination of the sample. This view was supported by normal results observed after abortion. Three out of 15 diagnostic c.v. samples with a female karyotype showed increased copper levels. In two of these cases, part of the copper content might have been released from the cannulae used for these particular biopsies. Histochemical visualization of copper accumulation in fixed chorionic villi of two affected fetuses and one female fetus was observed. [64Cu]-uptake studies have been performed on 11 diagnostic and 10 control c.v. samples. As the control samples in some cases were found to incorporate more [64Cu] than the corresponding diagnostic sample, this method cannot at present be used for diagnosis. Compiled results on newborn females gave evidence that two carriers expressed the paternal X-chromosome, and two carriers expressed the maternal X-chromosome in in chorionic villi.

Selection and characterization of monoclonal antibodies against a major allergen in Dermatophagoides pteronyssinus. Species-specific and common epitopes in three dermatophagoides species

Hybridomas were produced after immunization with Der p I (Ag 42, P1). Specific anti-Der p I activity was detected in a reverse ELISA using immobilized anti-mouse Ig and highly purified Der p I labelled with horseradish peroxidase. Stable subclones from 6 parental hybridomas were obtained. The species specificities of the monoclonal antibodies (MABs) were classified: by an overlayer technique analogous to the CRIE technique, and by two competitive ELISA techniques. One MAB recognized an epitope specific for Dermatophagoides pteronyssinus. This MAB was successfully employed as a coating reagent in a species-specific ELISA for Der p I in house dust. The remaining antibodies reacted with epitopes shared to varying degrees by either of two other Dermatophagoides species. MABs recognizing epitopes common to all 3 species were not observed. Mutual cross-inhibition studies revealed four topographically distinct antibody binding sites on Der p I.

Intestinal microflora, morphology and enzyme activity in zinc-deficient and Zn-supplemented rats

1. Immature, male Wistar rats were given a low-zinc diet (2 mg/kg) for 22-24 d. Control groups received a similar diet supplemented with 58 mg Zn/kg either ad lib., or in amounts matched to the consumption of the Zn-deficient group. Food consumption, rate of growth and food conversion efficiency were markedly lower in the Zn-deficient group of rats compared with controls. Appetite, growth rate and food utilization improved dramatically over a subsequent 4 d period of Zn supplementation. 2. Morphological examination of samples of jejunum and ileum confirmed that Zn deficiency in the rat is accompanied by a reduction in villous dimensions and increase in villous density. After a short period of Zn supplementation, villous density and the basal width and maximum height of individual villi in the jejunum returned to normal. Similar changes occurred in the ileum but to a lesser extent. 3. Mucosal alkaline phosphatase (EC 3.1.3.1) activity was significantly lower in the small intestine of Zn-deficient rats compared with Zn-supplemented rats. Disaccharidase activities were lower in the Zn-deficient group, compared with their feed-restricted counterparts, but were similar to values for ad lib.-fed controls. Tissue alkaline phosphatase and disaccharidase activities were consistently higher after a 4 d period of Zn supplementation, compared with non-supplemented animals, but this increase was only significant for alkaline phosphatase. 4. Although there were striking similarities in the mucosal characteristics of gnotobiotic and Zn-deficient rats, there was no indication that even severe dietary Zn depletion reduced the numbers of viable bacteria present in either the small or large intestine.(ABSTRACT TRUNCATED AT 250 WORDS)

Copper-measurement in a muscle-biopsy. A possible method for postmortem diagnosis of Menkes disease

A 5-month-old boy showed severe delay in mental and motor development. His hair was normal. He died at 18 months from bronchopneumonia. Autopsy of the brain revealed meningo-cerebral angiodysplasia with tortuous vessels at the surface of the brain. This raised a suspicion of Menkes disease. A muscle-biopsy, the only remaining tissue from the patient, showed an increased copper-content, thus corroborating the suspicion of Menkes disease. Copper-uptake studies on 2 independent repeatedly tested fibroblast-cultures from the mother gave normal values in 4 and elevated levels in three tests. Such a pattern is often seen in carriers of Menkes disease. Furthermore one of the test values was above the critical limit. Just one value above this limit for females from families with Menkes disease will unequivocally classify a woman as a carrier irregardless of her genetic risk. This is to our knowledge the first time copper-measurements in tissues have been used to establish a post-mortem diagnosis of Menkes disease.

Genetic epidemiology of Menkes disease

Copper incorporation studies were performed on individuals from 58 pedigrees, comprising 140 sibships. As previously reported, there is considerable overlap between heterozygotes and normal homozygotes. Segregation analysis supports recessive inheritance of disease, with residual heritability for 64Cu uptake in cultured cells. The population frequency of sporadic cases is compatible with the 1/3 expected for an X-linked lethal with equal mutation rates in egg and sperm, which implies a mutation rate of 6.7 X 10(-6)/gamete/generation. The parameters estimated here are likely to provide the best basis for genetic counseling until more reliable carrier tests are performed on a systematic sample from a large, defined population.

Linkage studies in Menkes' disease. The Xg blood group system and C-banding of the X chromosome

Menkes' disease is a rare, genetically determined disturbance of copper metabolism which is transmitted as an X-linked recessive character. By comparative gene mapping it can be suggested that the most likely localization of the gene for Menkes' disease is on the long arm of the human X chromosome close to band q 13. This regional assignment is supported by the present analysis of the genetic relationship between the Menkes locus, the Xg locus, and the centromere in five Danish families. The evidence suggests close linkage between the Menkes locus and the centromere. The most likely value of the recombination fraction is 0.05 and the maximum lod score is above the conventional +3 limit. Linkage analysis of the Menkes locus and the Xg locus showed a recombination value of 0.24, but the maximum conditional score is 0.28, which is far below the conventional +3 limit. The present study demonstrates a successful application of a chromosomal morphological marker in linkage analysis and carrier detection of a single gene disorder. The close linkage between the gene for Menkes' disease and the centromere region was used to improve the classification of several females in whom the copper uptake into cultured fibroblasts was either inconclusive or not available.

Alterations in copper and collagen metabolism in the Menkes syndrome and a new subtype of the Ehlers-Danlos syndrome

Cultured fibroblasts of 13 patients with the Menkes syndrome and two with a new subtype (type IX) of the Ehlers-Danlos syndrome (E-D IX patients) showed many very similar abnormalities in their copper and collagen metabolism. Both cell types had markedly increased copper concentrations and 64Cu incorporation, and this cation accumulated in metallothionein or a metallothionein-like protein, as previously established for Menkes cells. Histochemical staining indicated that copper was distributed diffusely throughout the cytoplasm in both cell types, this location being consistent with the accumulation in metallothionein. Both fibroblast types also had markedly low lysyl oxidase activity and distinctly increased extractability of newly synthesized collagen, whereas no abnormalities were present in cell viability, duplication rate, prolyl 4-hydroxylase activity, or collagen synthesis rate. A high negative correlation (P less than 0.001) was found in the pooled group of Menkes and E-D IX cells between cellular copper concentration (r = 0.804) or 64Cu incorporation (r = 0.863) and the logarithm of lysyl oxidase activity. There was also a high positive correlation (P less than 0.001) between cellular copper concentration and incorporation (r = 0.869). One of the two E-D IX patients was also shown to have similar changes in lysyl oxidase activity and collagen extractability in the skin biopsy specimen, suggesting that the abnormalities observed in cultured cells are similar to those present in vivo. The only distinct abnormality found in the cells of the parents of the E-D IX patients was an increased 64Cu incorporation in those of the mother, this finding being consistent with X-linked inheritance of the disorder.

Menkes kinky hair disease: a search for closely linked restriction fragment length polymorphism

In a large kindred with X-linked Menkes disease, linkage studies were performed with a restriction fragment length polymorphism (RFLP) that had been found with a cloned hybridisation probe from the proximal short arm of the X chromosome. This RFLP was considered as a potential genetic marker since the Menkes gene seems to be located near the centromere. Moreover, there is circumstantial evidence that in the (para) centric region of the X chromosome cross-overs are relatively rare. Unexpectedly, however, at least two cross-overs were detected in this family which suggests that the DNA sequence employed is of limited use for early diagnosis and carrier detection in this fatal hereditary disorder.

Menkes' X-linked disease: prenatal diagnosis and carrier detection

Increased 64Cu uptake into cultured cells is a biochemical marker for mutant cells in Menkes' disease (McKusick 30940). Using this marker selective prenatal diagnosis has been carried out in more than 80 at-risk pregnancies. The 64Cu uptake into cultures from affected male fetuses is however, negatively correlated to the fetal age at amniocentesis. After the 18th week of gestation the risk of false negatives is significant. Using copper uptake into uncloned cultures, a number of obligate and possible carriers showed significantly increased values, but the range of values of obligate carriers considerably overlapped those of the normal controls. All values of normal controls were within a limited range and values above the upper limit in females at risk must, therefore, be caused by mutant cells and establish the carrier diagnosis. However, the extreme skewing of the distribution towards normal values in obligate carriers indicates a strong selection against the mutant cell type and this will hamper the detection of all female carriers in risk families. C-banding heteromorphism of the X-chromosome provides a supplementary carrier detection method. Linkage analysis in five Danish families demonstrated a close physical relationship between the gene for Menkes' disease and the centromere region. By comparative gene mapping (mouse/man) the most likely localization of the gene for Menkes' disease can be suggested to be in band q13 on the long arm of the human X-chromosome. This regional assignment facilitates the choice of appropriate X-specific DNA probes in search for linkage at the DNA level.

A study of dopamine receptors in guinea-pig renal tissue

Dopamine and isoprenaline have been examined for their effects on guinea-pig renal blood flow in vivo and on cAMP production in a mainly isolated glomeruli/blood vessel preparation in vitro. The renal vasodilatation caused by both of these drugs can be differentiated by the use of specific antagonists, sulpiride blocking the effects of dopamine, and propranolol the vasodilatation produced by isoprenaline. Similarly, both drugs stimulated cAMP production, isoprenaline being much more active than dopamine (1000X) in this respect. Again, the dopamine antagonist fluphenazine specifically inhibited the dopamine-induced cAMP increases whilst the beta blocker atenolol blocked the rise in cAMP due to isoprenaline but not that due to dopamine. Sulpiride although potently inhibiting dopamine-induced renal vasodilatation was without effect on dopamine-stimulated cAMP levels. This result is similar to that reported in the CNS where sulpiride blocks dopamine activity in a variety of tests but is without effect on the dopamine-stimulated adenylate cyclase. Two dopamine agonists, ADTN and SKF 38393 were tested, and in both preparations had potent dopaminergic activity although SKF 38393 exhibited characteristics of a partial agonist on the adenylate cyclase model.

Menkes X-linked disease: prenatal diagnosis of hemizygous males and heterozygous females

Menkes X-linked disease, a copper disturbance syndrome, is detectable in cell cultures. Prenatal findings in two at-risk foetuses suggested that prenatal diagnosis was also feasible. In this study, we report substantial evidence that therapeutic abortion can be limited to hemizygous males. Forty-two at-risk pregnancies from 21 European families and 1 Canadian family were monitored with 64Cu-uptake into cultured amniotic fluid cells. In 10 pregnancies with a male karyotype an affected foetus was predicted on the basis of the copper studies. The pregnancies were terminated and the diagnosis was in each case confirmed by a markedly increased placenta copper content. Fourteen male foetuses were predicted to be unaffected and none of them has developed signs of Menkes disease after birth. In 6 of these cases the diagnosis was checked in the newborn boy by placenta copper measurements, and they all had copper concentrations within normal limits. Eighteen pregnancies with a female karyotype were also studied, 9 females could be identified as carriers on the basis of the tissue culture studies or raised placenta copper values.

Menkes X linked disease: two clonal cell populations in heterozygotes

The 64Cu incorporation into fibroblast clones obtained from three obligate and three suspected Menkes disease heterozygotes was studied. For each obligate heterozygote, two clonal cell populations were observed, one with a Menkes phenotype and one with a normal phenotype, as predicted by the Lyon hypothesis. The cloning results suggested a heterozygous state in two of the suspected carriers. The theoretical and practical limitation of the cloning method for identification of carriers of X linked diseases are discussed.

Menkes X linked disease: heterozygous phenotype in uncloned fibroblast cultures

The 64Cu incorporation into uncloned fibroblast cultures from 16 Menkes disease mothers and 19 first and second degree female relatives was examined. The mean incorporation for the Menkes disease mothers (36.2 +/- 3.6 SEM) differed significantly from that of 25 normal subjects (21.7 +/- 0.9 SEM) suggesting the presence of a significant proportion of mutant cells. In addition, the results suggested a heterozygous state in a number of the female relatives. Uncloned fibroblast cultures from four Menkes disease heterozygotes showed increasingly abnormal copper uptake values after repeated freezing procedures. Manipulation of tissue cultures may help to identify a number of female carriers.

Menkes syndrome: subcellular distribution of copper determined by an ultrastructural histochemical technique

Several cell types from male infants with Menkes disease accumulate increased amounts of copper. Ultrastructural localization of copper by a histologic staining technique and X-ray microanalysis is established the subcellular distribution of the metal. In Menkes patients, copper was heavily concentrated on the brush border of intestinal epithelium as well as on the plasma membrane of cultured fibroblasts. The transport defect seems to be caused by a decreased transport of copper across plasma membrane, which mainly affects the influx mechanism.

8402 human cell culture--a model for evaluating bilirubin-albumin interactions with drug

The effect of therapeutic concentration of sulfisuxazole (sulfa) on the bilirubin uptake and viability of 8402 cells in culture was studied. The total bilirubin was kept constant at 24 microM and albumin was added to obtain bilirubin-albumin molar ratio (BAMR) ranging from 0.5 to 2. The effect of sulfa on unbound bilirubin (UB) was measured by the peroxidase assay. Sulfa increased UB at all BAMR's more so at 1.5 and 2.0 (P less than 0.05). Significant increase in bilirubin uptake/cell with a corresponding decrease in cell viability was noted with sulfa at BAMR's greater than 1 (P less than 0.05). The LD50 of these cells was 73-86 nM of UB. A plot of cell viability versus UB for the combined control and sulfa data (r2 = 0.94) confirms that the decrease in cell viability with increasing BAMR is explained by the corresponding rise in UB. Therefore, increase in UB by sulfa leads to toxicity of 8402 cells. Thus, we speculate that they may be used to study the mechanism of bilirubin neurotoxicity induced by similar drugs.

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.

Extra-hepatic storage of copper: a male foetus suspected of Menkes' disease

The distribution of copper among the organs of an aborted, male foetus, expected to develop Menkes' syndrome, was entirely different from the distribution in 4 normal foetuses. Copper concentrations determined by neutron activation analysis showed a considerably reduced content in the liver, but increased concentrations in the other organs analysed; total foetal copper was normal.