Psychological aspects of patients with Fabry disease.

The Minnesota Muliphasic Personality Inventory (MMPI-2) is widely used in chronic illness and chronic pain populations to assess psychological functioning. We report the results of the first investigation using the MMPI-2 to assess psychological aspects of patients with Fabry disease. Fabry disease, an X-linked lysosomal storage disorder, is a multisystem progressive disease affecting the kidney, heart, and central nervous system, and is particularly associated with chronic symptoms including pain. In this study, 28 patients with Fabry disease completed the MMPI-2 and a background questionnaire. Fabry disease patients scored significantly higher than the MMPI-2 normative sample on seven clinical scales (Hs, D, Hy, Pd, Pa, Pt, Sc) and two validity scales (L, F). Individuals with elevated scores on the Hs, D, and Hy scales tend to have somatic complaints, sadness, and emotional distress. Under stress, they may experience an increase in physical symptoms. Elevated Pd, Pa, Pt, and Sc scales suggest social maladjustment, suspiciousness, and feelings of isolation. An elevated L scale suggests defensiveness; a high score on F suggests emotional turmoil. When compared with cohorts of patients with Gaucher disease (GD), chronic heart disease (CRHD), and chronic pain, the Fabry disease patients had significantly higher scores than GD patients and CRHD patients on numerous clinical (Hs, D, Si), and validity (F) scales underscoring the relative amount of suffering and pain experienced by Fabry disease patients. No significant differences on any MMPI-2 scales were found between the Fabry disease patients and the pain patients, suggesting that Fabry disease patients may be comparable to pain patient populations.

Periventricular heterotopia associated with chromosome 5p anomalies.

Periventricular heterotopia (PH) is characterized by neuronal nodules along the lateral ventricles. Whereas mutations in X-linked FLNA cause such cortical malformations, the authors report two cases of PH localizing to chromosome 5p. Both subjects have complex partial seizures. MRI demonstrated bilateral nodular PH, with subcortical heterotopia or focal gliosis. FISH identified a duplication of 5p15.1 [46,XX,dup(5)(p15.1p15.1)] and a trisomy of 5p15.33 [46,XY,der(14)t(5;14)(p15.33;p11.2) mat]. These findings suggest a new PH locus along the telomeric end of chromosome 5p.

Mutation analysis and expression of the mottled gene in the macular mouse model of Menkes disease.

The gene for Menkes disease, an X-linked disorder of copper transport, has recently been identified and shown to encode a copper-transporting P-type ATPase. The macular mutant mouse has been proposed as an animal model for Menkes disease. In the present study, we report the finding of a missense mutation in the mottled gene of the macular mouse. A single base change, T to C, at nucleotide position 4223, is predicted to result in an amino acid change from serine to proline at residue 1382 in the eighth transmembrane domain. This mutation differs from the 6-bp deletion we find in brindled cDNA. With validation of macular as an animal model of Menkes disease, we compared mottled gene expression in the intestine, kidney, and brain of macular and normal mice. In Northern analyses an 8.3-kb transcript was detected in the intestine, kidney, and brain of both normal and macular mice, with the level of transcript in macular approximately 80% that of normal. In situ hybridization studies revealed that the mottled gene was clearly expressed in intestinal epithelial cells, Paneth cells, and renal proximal tubular cells of both normal and macular mice. In normal brain, mottled gene expression was most intensely observed in the choroid plexus, in Ammon's born and the dentate gyrus in the hippocampus, in Purkinje cells, and the granular layer of the cerebellum. The intensity and localization of the signals in the brain of macular mice were similar to those of the controls. The distribution of expression of mottled is correlated with cells and tissues showing histopathology or abnormal copper sequestration in macular and other mutants.

Developmental expression of the mouse mottled and toxic milk genes suggests distinct functions for the Menkes and Wilson disease copper transporters.

Menkes disease and Wilson disease are human disorders of copper transport caused by mutations in distinct genes encoding similar copper-transporting P-type ATPases. These genes are expressed in different adult tissues in patterns reflecting disease manifestations. The mouse homologues for the Menkes (MNK) and Wilson (WND) disease genes are the mottled (Atp7a) and toxic milk (Atp7b) genes, respectively. Using RNA in situ hybridization we describe the distribution of mottled and toxic milk transcripts during mouse embryonic development. The mottled gene is expressed in all tissues throughout embryogenesis and is particularly strong in the choroid plexuses of the brain. Mottled expression in the liver is in contrast to the prior observation of absent or very low expression in the adult liver. Expression of the toxic milk gene is significantly more delimited, with early expression in the central nervous system, heart and liver. Later in gestation, toxic milk transcript is clearly seen in the liver, intestine, thymus and respiratory epithelium including nasopharynx, trachea and bronchi. In lung, toxic milk expression is restricted to bronchi, while mottled expression is diffuse. Hepatic expression of both toxic milk and mottled is in the parenchyma, as opposed to blood cells. These results suggest that the mottled gene product functions primarily in the homeostatic maintenance of cell copper levels, while the toxic milk gene product may be specifically involved in the biosynthesis of distinct cuproproteins in different tissues.

Methylmalonic acidemia, cobalamin C type, presenting with cutaneous manifestations.

BACKGROUND: Erosive dermatitis resembling the skin lesions of acrodermatitis enteropathica has been described in a number of aminoacidopathies and organic acidemias. In some, the dermatitis is a manifestation of untreated disease, while in others, including methylmalonic acidemia, skin lesions have been ascribed to nutritional deficiency due to therapeutic amino acid restrictions. OBSERVATIONS: We report 2 cases of methylmalonic acidemia presenting with cutaneous manifestations in the perinatal period before restrictive nutritional interventions. The cutaneous involvement consisted of cheilitis and diffuse erythema with erosions and desquamation. Methylmalonic acidemia, cobalamin C type, was subsequently diagnosed in both cases. CONCLUSIONS: An erosive, desquamating dermatitis with histopathologic characteristics resembling acrodermatitis enteropathica may be a presenting sign in cobalamin C methylmalonic acidemia, even in the absence of long-standing nutritional restrictions or deficiency.

A repeated element in the regulatory region of the MNK gene and its deletion in a patient with occipital horn syndrome.

Occipital horn syndrome (OHS), an X-linked connective tissue disorder, has recently been shown to result from mutations in the Menkes disease gene (MNK), which encodes a copper-transporting ATPase. By Southern analysis we detected a small deletion in a region 5' to the MNK gene in one patient with OHS. Genomic clones from an unaffected individual were isolated and sequenced, revealing three tandem 98 bp repeats situated upstream of the reported transcription start site, and analysis of the patient's DNA showed a deletion of one of the repeats. The deletion is likely to be responsible for the disease in this patient, as it was not observed in 110 unaffected individuals analyzed, and no other mutation in the patient was detected by RT-PCR and chemical cleavage mismatch analysis or by cDNA sequence analysis. The deletion is associated with a dramatic decrease in expression of a chloramphenicol acetyltransferase reporter gene, implicating the repeat sequences in regulation of MNK expression, although a quantitative analysis of MNK mRNA from a cell line derived from the patient shows no detectable reduction. Other experiments revealed no effect on the site of transcription initiation, termination or on splicing.

Outcome of unrelated donor bone marrow transplantation in 40 children with Hurler syndrome.

Long-term survival and improved neuropsychological function have occurred in selected children with Hurler syndrome (MPS I H) after successful engraftment with genotypically matched sibling bone marrow transplantation (BMT). However, because few children have HLA-identical siblings, the feasibility of unrelated donor (URD) BMT as a vehicle for adoptive enzyme therapy was evaluated in this retrospective study. Forty consecutive children (median, 1.7 years; range, 0.9 to 3.2 years) with MPS I H received high-dose chemotherapy with or without radiation followed by BMT between January 27, 1989 and May 13, 1994. Twenty-five of the 40 patients initially engrafted. An estimated 49% of patients are alive at 2 years, 63% alloengrafted and 37% autoengrafted. The probability of grade II to IV acute graft-versus-host disease (GVHD) was 30%, and the probability of extensive chronic GVHD was 18%. Eleven patients received a second URD BMT because of graft rejection or failure. Of the 20 survivors, 13 children have complete donor engraftment, two children have mixed chimeric grafts, and five children have autologous marrow recovery. The BM cell dose was correlated with both donor engraftment and survival. Thirteen of 27 evaluable patients were engrafted at 1 year following URD BMT. Neither T-lymphocyte depletion (TLD) of the bone marrow nor irradiation appeared to influence the likelihood of engraftment. Ten of 16 patients alive at 1 year who received a BM cell dose greater than or equal to 3.5 x 10(8) cells/kg engrafted, and 62% are estimated to be alive at 3 years. In contrast, only 3 of 11 patients receiving less than 3.5 x 10(8) cells/kg engrafted, and 24% are estimated to be alive at 3 years (P = .05). The mental developmental index (MDI) was assessed before BMT. Both baseline and post-BMT neuropsychological data were available for 11 engrafted survivors. Eight children with a baseline MDI greater than 70 have undergone URD BMT (median age, 1.5 years; range, 1.0 to 2.4 years). Of these, two children have had BMT too recently for developmental follow-up. Of the remaining six, none has shown any decline in age equivalent scores. Four children are acquiring skills at a pace equal to or slightly below their same age peers; two children have shown a plateau in learning or extreme slowing in their learning process. For children with a baseline MDI less than 70 (median age, 2.5 years; range, 0.9 to 2.9 years), post-BMT follow-up indicated that two children have shown deterioration in their developmental skills. The remaining three children are maintaining their skills and are adding to them at a highly variable rate. We conclude that MPS I H patients with a baseline MDI greater than 70 who are engrafted survivors following URD BMT can achieve a favorable long-term outcome and improved cognitive function. Future protocols must address the high risk of graft rejection or failure and the impact of GVHD in this patient population.

Use of amniotic fluid amino acids in prenatal testing for argininosuccinic aciduria and citrullinaemia.

Prenatal testing of 12 pregnancies at risk for argininosuccinic aciduria due to argininosuccinate lyase (ASAL) deficiency and three pregnancies at risk for citrullinaemia due to argininosuccinate synthatase (ASAS) deficiency was performed by metabolite detection in amniotic fluid and measurement of enzyme activity in uncultured and cultured chorionic tissue and in cultured amniocytes. From our data and those of previous studies, amniotic fluid argininosuccinate measurement alone is clearly a reliable and rapid diagnostic test for both severe and mild ASAL deficiency if maternal ASAL deficiency can be excluded. For prenatal diagnosis of ASAS deficiency, however, both measurement of the amniotic fluid citrulline level and enzyme assay should be employed.

Successful early copper therapy in Menkes disease associated with a mutant transcript containing a small In-frame deletion.

Classical Menkes disease is a fatal X-linked neurodegenerative disorder caused by defects in a gene (MNK) that encodes a copper-transporting ATPase. Treatment with parenteral copper has been proposed for patients identified before symptoms develop. We recently described suboptimal outcomes despite early copper replacement in two classical Menkes patients whose mutation predicts little if any functional copper transporter. Here, we describe successful copper replacement therapy in a patient with Menkes disease with a splice acceptor site mutation (IVS8,AS,dup5) that causes exon-skipping and generates a mutant transcript with a small in-frame deletion in a noncritical region. The patient was diagnosed by analysis of neurochemical levels in cord blood, and parenteral copper replacement was begun at 8 days of life. Throughout infancy, he showed normal head growth, brain myelination, and age-appropriate neurodevelopment, including independent walking at 14 months of age. In contrast, his affected half-brother and first cousin with the same mutation, but who were not diagnosed and treated from an early age, showed arrested head growth, cerebral atrophy, delayed myelination, and abnormal neurodevelopment. We propose that the successful neurological outcome in this patient was related to early repletion of circulating copper levels, in combination with residual copper transport by a partially functional MNK ATPase containing the small deletion. We hypothesize that raising plasma copper concentrations in patients with Menkes disease with some residual functional gene product can increase the ligand: transporter ratio and thus alter favorably the kinetics of copper transport into and within the brain.

Similar splicing mutations of the Menkes/mottled copper-transporting ATPase gene in occipital horn syndrome and the blotchy mouse.

The connective-tissue disorder occipital horn syndrome (OHS) is hypothesized to be allelic to Menkes disease. The two diseases have different clinical presentations but have a similar abnormality of copper transport. Mice hemizygous for the blotchy allele of the X-linked mottled locus have similar connective-tissue defects as OHS and may represent a mouse model of this disease. We have analyzed the Menkes/mottled copper-transporting ATPase in these two potentially homologous disorders and have identified similar splicing mutations in both. Some expression of normal mRNA was detectable by reverse transcription-PCR in the mutant tissues. These findings contrast with the more debilitating mutations observed in Menkes disease and suggest that low amounts of an otherwise normal protein product could result in the relatively mild phenotype of OHS and of the blotchy mouse.

Cellular copper transport.

Cellular copper transport processes are required by all organisms for correct utilization in cell biochemical processes and avoidance of the toxicity of copper excess. Copper import into bacterial, yeast, and mammalian cells requires the coordinate function of proteins with both metal-binding and catalytic domains in mediated transport steps. Following entry, detoxification mechanisms found across species include the binding of copper to specific proteins (e.g. metallothioneins) and the transfer of copper into isolated cell compartments (e.g. periplasmic space, lysosome). Multiple proteins mediate intracellular transfers in bacteria, and glutathione may play a major role in cytosolic copper delivery to cuproenzymes in mammalian cells. Study of two human disorders of copper transport, Menkes disease and Wilson disease, led to the identification of an important category of proteins mediating cell copper export. The Menkes and Wilson disease gene products are copper-transporting ATPases of the P type, with ATPase domains and N-terminal metal-binding amino acid motifs that are evolutionarily conserved in unicellular and mammalian organisms. These observations suggest that yeast and bacterial copper transport proteins, or individual domains of these proteins, may generally have homologues in mammalian systems.

Trichothiodystrophy: clinical spectrum, central nervous system imaging, and biochemical characterization of two siblings.

Trichothiodystrophy (TTD), an autosomal recessive disorder characterized by sulfur-deficient brittle hair, identifies a group of genetic disorders with an altered synthesis of high-sulfur matrix proteins and a defect in excision repair of ultraviolet damage in fibroblasts of most TTD patients. In contrast to patients with xeroderma pigmentosum (XP), TTD patients do not have an increased frequency of skin cancers. TTD patients may be grouped into four categories: 1) those without photosensitivity and without a defect in excision repair of UV damage; 2) those without photosensitivity and with an excision-repair defect in the same gene as in XP-D (complementation group D); 3) those with photosensitivity and with the XP-D repair defect; 4) those with photosensitivity and with a repair defect distinct from that in XP-D. We present a brother and sister in the third category of TTD. Clinically, the patients have brittle hair, short stature, ichthyosis, photosensitivity, nail and dental dysplasias, cataracts, mental retardation, and pyramidal tract abnormalities. Diagnosis was made by hair mount, which shows the characteristic banding pattern with polarizing microscopy, and by hair amino acid analysis, which demonstrated decreased high-sulfur matrix proteins. Fibroblasts cultured from skin biopsies had a marked DNA excision repair defect similar to the repair defect seen in XP-D. We have documented a unique dysmyelinating disorder on magnetic resonance imaging of the brain that might explain their mental retardation, marked hyperactivity, and neurologic deficits. Following the discovery that the human excision repair cross complementing rodent ultraviolet group 2 (ERCC2) gene is able to correct the ultraviolet sensitivity of XP-D cell strains, the ERCC2 cDNA from previous TTD patients was sequenced and shows frameshifts, deletions and point mutations in the ERCC2 gene. Molecular analysis of our patients is in progress. Molecular analysis of the defects in ERCC2 in clinically distinct patients with XP,XP/Cockayne's syndrome, and TTD may provide insight into the molecular mechanisms of these genetically related but clinically distinct disorders.

The mottled gene is the mouse homologue of the Menkes disease gene.

The mottled mouse has been proposed as an animal model for Menkes disease, an X-linked disorder of copper transport. The recent isolation of a copper-transporting ATPase gene responsible for Menkes disease has allowed us to test this hypothesis. Here we report the isolation and sequence of the mouse homologue of this gene. We show that two mottled (Mo) alleles, dappled (Modp) and blotchy (Moblo), have abnormalities in the murine mRNA and that Modp has a partial gene deletion. These studies prove that the mottled mouse is the murine model for Menkes disease, providing the basis for future biochemical and therapeutic studies.

Isolation of a candidate gene for Menkes disease and evidence that it encodes a copper-transporting ATPase.

Menkes disease is an X-linked disorder of copper transport characterized by progressive neurological degeneration and death in early childhood. We have isolated a candidate gene (Mc1) for Menkes disease and find qualitative or quantitative abnormalities in the mRNA in sixteen of twenty-one Menkes patients. Four patients lacking Mc1RNA showed rearrangements of the Menkes gene. The gene codes for a 1,500 amino acid protein, predicted to be a P-type cation-transporting ATPase. The gene product is most similar to a bacterial copper-transporting ATPase and additionally contains six putative metal-binding motifs at the N-terminus. The gene is transcribed in all cell types tested except liver, consistent with the expression of the Menkes defect.

Homocystinuria presenting as sagittal sinus thrombosis.

Thrombotic and thromboembolic complications are the main causes of morbidity and mortality in patients with homocystinuria. However, it is unusual for thrombosis to be the single clinical feature leading to investigation for homocystinuria. We report an academically superior teenage boy who presented with sagittal sinus thrombosis, papilledema, transient right hemiparesis, and pneumothoraces. Pyridoxine-unresponsive homocystinuria was diagnosed by aminogram, enzyme assay, and clinical trial. Treatment has been with methionine restriction and betaine. Homocystinuria should be considered in patients with unusual vascular lesions or premature thromboembolism.

Pyridoxine-unresponsive homocystinuria with an unusual clinical course.

Progressive premature atherosclerosis and associated thromboembolic complications are the main causes of morbidity and mortality in patients with homocystinuria. However, thrombosis is rarely the predominant or presenting manifestation leading to the diagnosis of homocystinuria. We report on an otherwise asymptomatic teenage boy of normal intelligence who had a superior sagittal sinus thrombosis documented by CT and MRI scans. He presented with pneumothoraces, papilledema, and transient right hemiparesis. He subsequently developed empyema and necrotizing pneumonia as well as deep venous thromboses. The diagnosis of pyridoxine-unresponsive homocystinuria was made on the basis of clinical chemistry analyses, enzyme assay, and clinical trial. He has remained symptom-free under treatment with betaine and methionine restriction. We suggest that there exists a subset of patients with pyridoxine-unresponsive homocystinuria who are at risk for thromboembolism, but who may remain undiagnosed because of an otherwise mild clinical course.

Location of the retinoblastoma susceptibility gene(s) and the human esterase D locus.

Retinoblastoma occurs with increased frequency in children born with a deletion of the long arm of chromosome 13. Recent reviews have noted that the region 13q14 is consistently deleted in documented cases. Prometaphase and late prophase banding allowed Yunis and Ramsay to determine that a deletion in one patient included the sub-bands q14 . 12, q14 . 13, and q14 . 2, and a portion of q14 . 11 and q14 . 3. We report the results of similar cytogenetic techniques applied in the case of a 26 month old Caucasian female with unilateral retinoblastoma, moderate developmental delay, and subtle dysmorphology. Prometaphase banding of cultured skin fibroblasts revealed the karyotype: mos46,XX/46,XX,del(13)(q13 . 1q14 . 11). Only the sub-band q14 . 11 is deleted in both our patient and that of Yunis and Ramsay. The results are consistent with the localisation of the retinoblastoma susceptibility gene(s) in the sub-band 13q14 . 11. Electrophoretic analysis and activity assays of red blood cell esterase D are consistent with hemizygous expression of that marker in our proband. Comparison with published esterase D analyses in families with retinoblastoma permits the assignment of the esterase D locus to that same sub-band, 13q14 . 11.