1/191. Slow progression of juvenile metachromatic leukodystrophy 6 years after bone marrow transplantation.Metachromatic leukodystrophy refers to a group of genetic neurologic diseases caused by deficiencies of the enzyme arylsulfatase A and the resulting accumulation of sulfatides in white matter. bone marrow transplantation has been advocated as a treatment in an attempt to correct the enzyme deficiency. Such a transplant was performed in 1991 in a 16-year-old girl with a form of late juvenile metachromatic leukodystrophy caused by a homozygous P426L mutation in the arylsulfatase A gene. Engraftment was prompt and resulted in constant enzymatic normalization of circulating lymphocytes. The elevated urinary excretion of sulfatides remained unaffected. Clinical findings up until transplantation consisted of gait disturbances, impairment of cognitive functioning, and deterioration in school performance over several years. During a 6-year follow-up period, the patient's condition was subject to major fluctuations but, on the whole, findings showed slow neurologic and neurophysiologic deterioration. The clinical course observed after bone marrow transplantation probably more or less reflects the natural course expected in this form of late-onset metachromatic leukodystrophy.- - - - - - - - - - ranking = 1keywords = deficiency, b (Clic here for more details about this article) |
2/191. adult-type metachromatic leukodystrophy with a compound heterozygote mutation showing character change and dementia.A 26-year-old Japanese woman slowly developed a change of character such as hypospontaneity and blunted affect, followed by obvious mental deterioration. She was diagnosed as having a disorganized type of schizophrenia at the first examination. brain magnetic resonance imaging demonstrated diffuse high intensity in the cerebral white matter, particularly in the frontal lobes. The single photon emission computed tomography images using 123I-IMP disclosed diffuse cerebral hypofusion, especially in the frontal lobes. Electroencephalogram showed a moderate amount of 5-6Hz theta waves on the background of alpha activity. Nerve conduction velocities in the extremities were delayed. The level of leucocyte arylsulphatase was low. In the arylsulphatase A gene analysis, a compound heterozygote having the 99Gly-->Asp and 409Thr-->Ile mutations was confirmed. The patient was diagnosed as having metachromatic leukodystrophy. She gradually showed obvious dementing symptoms such as memory disturbance and disorientation. The characteristics of the psychiatric symptoms in the leukodystrophy are discussed.- - - - - - - - - - ranking = 0.0025520312446865keywords = b (Clic here for more details about this article) |
3/191. MRI appearances of metachromatic leukodystrophy.BACKGROUND: The leukodystrophies constitute a wide spectrum of cerebral disorders of varying etiology. The imaging appearances on CT and MRI are recognizable as abnormalities of white matter; however, it may be impossible to arrive at the correct diagnosis based on imaging studies alone. patients AND methods: Three patients of varying age and clinical symptomatology diagnosed with metachromatic leukodystrophy (MLD) had remarkably similar MRI appearances. A "tigroid" or "leopard-skin" appearance was demonstrated within deep white matter in each case. RESULTS: All of the patients had biochemical confirmation of MLD. CONCLUSION: Although the "tigroid" pattern previously was considered to be pathognomonic of pelizaeus-merzbacher disease, the diagnosis of MLD must now be considered when these MRI appearances are encountered.- - - - - - - - - - ranking = 0.0028072343691552keywords = b (Clic here for more details about this article) |
4/191. Spontaneous rupture of the diaphragm.A 2.5 year old girl with metachromatic leukodystrophy presented with acute respiratory distress and was initially wrongly diagnosed with pneumothorax. barium meal showed bowel loops in the left hemithorax, which prompted surgical intervention; spontaneous rupture of the diaphragm was diagnosed at surgery.- - - - - - - - - - ranking = 0.00025520312446865keywords = b (Clic here for more details about this article) |
5/191. Sulfatide cholecystosis.Polypoid masses metachromatic sulfatides have been found at autopsy in the gallbladder of patients with metachromatic leucodystrophy. In a 10-year-old girl with this disease oral cholecystrography demonstrated a filling defect, which was felt to represent a polyp. In the proper clinical setting, sulfatide cholecystosis should be considered in the differential diagnosis of polypoid lesions of the gallbladder.- - - - - - - - - - ranking = 0.0010208124978746keywords = b (Clic here for more details about this article) |
6/191. Metachromatic leucodystrophy: a newly identified mutation in arylsulphatase A, D281Y, found as a compound heterozygote with I179L in an adult onset case.The majority of mutations identified in patients with Metachromatic leucodystrophy are unique to individual families. We report here a new mutation in the arylsulphatase A gene (D281Y) identified in a patient with late-onset Metachromatic leucodystrophy. This mutation was inherited in cis with the common pseudo-deficiency allele and in trans with the previously described I179S (250100.0008) mutation which complicated the enzymatic diagnosis of this condition. Sequence comparison shows D281 to be highly conserved amongst the arylsulphatases. The clinical features of this patient which are predominantly of a slowly progressive psychiatric and intellectual deterioration rather than rapid neurological impairment are typical of I179S compound heterozygotes.- - - - - - - - - - ranking = 0.99693756250638keywords = deficiency, b (Clic here for more details about this article) |
7/191. Early thalamic and cortical hypometabolism in adult-onset dementia due to metachromatic leukodystrophy.A case of early-onset adult dementia with family history of dementia is reported, characterised by neuropsychological deficits, suggesting frontal involvement, with mild non specific white matter abnormalities on CT scan. Familial Alzheimer's disease was suspected but the neuropathological diagnosis on brain biopsy was metachromatic leukodystrophy. 18FDG-PET revealed a very peculiar pattern of metabolic impairment in thalamic areas, in medial and frontopolar regions, and in occipital lobes. Neuropsychological follow-up showed relatively stable difficulties of long-term memory and signs of frontal lobe dysfunction, similar to those observed in subcortical dementias. MRI subsequently showed periventricular leukoencephalopathy. The brain metabolic pattern observed in that case of metachromatic leukodystrophy was quite different from that reported in other types of dementia.- - - - - - - - - - ranking = 0.0048488593649044keywords = b (Clic here for more details about this article) |
8/191. neurophysiology and MRI in late-infantile metachromatic leukodystrophy.We present serial clinical, radiologic, and neurophysiologic findings of a patient with late-infantile metachromatic leukodystrophy who was first admitted at 30 months of age because of gait disturbance. The neurologic findings were consistent with mild spastic diplegia (occasionally with toe walking). magnetic resonance imaging disclosed diffuse high intensity in the cerebral white matter on T2-weighted images. Nerve conduction velocity studies and evoked-potential studies were markedly abnormal. Assay of arylsulfatase A activity in leukocyte culture disclosed a marked deficiency of the enzyme, confirming the diagnosis of late-infantile metachromatic leukodystrophy. Serial neurophysiologic studies demonstrated a marked decrease of nerve conduction velocities, both motor and sensory, as well as prolongation or disappearance of brainstem auditory-, visual-, and somatosensory-evoked potential latencies. magnetic resonance imaging studies revealed initially diffuse increased signal intensity of periventricular and subcortical white matter on T2-weighted images, progressing to cortical atrophy with involvement of the arcuate fibers and the cerebellar white matter, correlating with the clinical deterioration (severe spastic tetraplegia with optic atrophy and epilepsy).- - - - - - - - - - ranking = 0.99872398437766keywords = deficiency, b (Clic here for more details about this article) |
9/191. A non-glycosylated and functionally deficient mutant (N215H) of the sphingolipid activator protein B (SAP-B) in a novel case of metachromatic leukodystrophy (MLD).The lysosomal degradation of sphingolipids with short oligosaccharide chains depends on small glycosylated non-enzymatic sphingolipid activator proteins (SAPs, saposins). Four of the five known SAPs, SAP-A, -B, -C and -D, are derived by proteolytic processing from a common precursor protein (SAP-precursor) that is encoded by a gene on chromosome 10 consisting of 15 exons and 14 introns. SAP-B is a non-specific glycolipid binding protein that stimulates in vitro the hydrolysis of about 20 glycolipids by different enzymes. In vivo SAP-B stimulates in particular the degradation of sulphatides by arylsulphatase A. So far, four different point mutations have been identified on the SAP-B domain of the SAP-precursor gene. The mutations result in a loss of mature SAP-B, causing the lysosomal accumulation of sulphatides and other sphingolipids, resulting in variant forms of metachromatic leukodystrophy (MLD). Here we report on a patient with SAP-B deficiency that is caused by a new homoallelic point mutation that has been identified by mRNA and dna analysis. A 643A > C transversion results in the exchange of asparagine 215 to histidine and eliminates the single glycosylation site of SAP-B. Metabolic labelling experiments showed that the mutation had no effect on the intracellular transport of the encoded precursor to the acidic compartments and its maturation in the patient's cells. All four SAPs (SAP-A to SAP-D) were detectable by immunochemical methods. SAP-B in the patient's cells was found to be slightly less stable than the protein in normal cells and corresponded in size to the deglycosylated form of the wild-type SAP-B. Feeding studies with non-glycosylated SAP-precursor, generating non-glycosylated SAP-B, showed that the loss of the carbohydrate chain reduced the intracellular activity of the protein significantly. The additional structural change of the patient's SAP-B, caused by the change of amino acid 215 from asparagine to histidine, presumably resulted in an almost completely inactive protein.- - - - - - - - - - ranking = 1.0012760156223keywords = deficiency, b (Clic here for more details about this article) |
10/191. Characterization of four arylsulfatase A missense mutations G86D, Y201C, D255H, and E312D causing metachromatic leukodystrophy.Metachromatic leukodystrophy is a lysosomal storage disease caused by the deficiency of arylsulfatase A. Here we describe a hitherto unknown arylsulfatase A allele carrying a E312D missense mutation and characterize the effects of this and three previously described missense mutations, G86D, Y201C, and D255H, on arylsulfatase A. In transfection experiments no enzyme activity can be expressed from arylsulfatase A cDNAs coding for the D255H substituted enzyme, whereas Y201C and E312D mutations were associated with low amounts of residual enzyme activity. All amino acid substitutions lead to a decreased stability of the mutant enzyme, and metabolic labeling experiments indicated that except for the E312D substitution the mutations cause arrest of the mutant arylsulfatase A polypeptides in a prelysosomal compartment.- - - - - - - - - - ranking = 0.99897918750213keywords = deficiency, b (Clic here for more details about this article) |
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