Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two adult Ashkenazi Jewish siblings have had slowly progressive deterioration of gait and posture since early childhood, distal to proximal muscle atrophy, pes cavus, foot drop, spasticity, mild ataxia of limbs and trunk, dystonic features, and dysarthria. Vision and optic fundi are normal, verbal intelligence is stable, and no seizures have occurred. The sister of the patients died at 16 years of age with the same illness. Autopsy showed diffuse neuronal storage, predominating in subcortical areas, consisting of membranocytoplasmic bodies, zebra bodies, and complex lamellar structures. GM2 ganglioside was increased in her brain. Hexosaminidase A was decreased in serum and leukocytes of the living patients, and was in the range for carriers of Tay-Sachs disease in their parents. The disease found in this family represents a new, more indolent variant of GM2 gangliosidosis.
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PMID:Adult (chronic) GM2 gangliosidosis. Atypical spinocerebellar degeneration in a Jewish sibship. 17 70

Abnormality in the beta-hexosaminidase alpha gene underlying the clinical phenotype of a Lebanese patient with a juvenile form of Tay-Sachs disease has been studied. Clinical features were progressive spasticity, ataxia, and cognitive decline. The protein coding sequence of several beta-hexosaminidase alpha-chain complementary DNAs isolated by polymerase chain reaction was completely normal except for a G-to-A transition at nucleotide position 1511 within exon 13, which resulted in substitution of the normal arginine 504 (CGC) with histidine (CAC). Although the patient was from a first-cousin marriage, she was heterozygous for this mutation. The abnormality in the other allele, which is carried by the father, was not identified, except that it is neither of the two mutations responsible for the infantile Jewish Tay-Sachs disease. Biosynthetic and immunoprecipitation studies in cultured fibroblasts showed synthesis of the alpha-chain precursor, but the mature form of the alpha-subunit was not detected.
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PMID:Genetic cause of a juvenile form of Tay-Sachs disease in a Lebanese child. 199 72

An Ashkenazi Jewish brother and sister developed progressive ataxia and proximal neurogenic muscle weakness, associated with supranuclear ophthalmoplegia, in the fourth decade of life. Hexosaminidase A activity, assayed using both synthetic and natural substrates, was severely reduced in the patients' plasma, leukocytes, and skin fibroblasts. Enzyme activity in their parents was in a similar range to that seen in heterozygotes for Tay-Sachs disease. The increasing evidence for marked clinical and molecular heterogeneity in the GM2 gangliosidoses warrants their consideration in the diagnosis of multisystem degenerative neurological disorders, even if onset of symptoms is in adult life.
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PMID:Adult onset supranuclear ophthalmoplegia, cerebellar ataxia, and neurogenic proximal muscle weakness in a brother and sister: another hexosaminidase A deficiency syndrome. 295 62

A 24-year-old man presented with dystonia, dementia, amyotrophy, choreoathetosis, and ataxia. Partial hexosaminidase A deficiency was documented in serum and leukocytes and confirmed by rectal biopsy with ganglion cells containing membranous cytoplasmic bodies. A brief review of the literature reveals that tremor, dystonia and choreoathetosis are common but neglected symptoms associated with chronic GM2 gangliosidosis.
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PMID:Movement disorders associated with chronic GM2 gangliosidosis. Case report and review of the literature. 308 50

We studied three patients from two unrelated families with adult hexosaminidase A deficiency. A 30-year-old, non-Jewish proband in the first family had juvenile amyotrophic lateral sclerosis that evolved to mild dementia, ataxia, and axonal (neuronal) motor-sensory peripheral neuropathy. A 36-year-old Jewish proband in the second family had "pure" spinal muscular atrophy. One supposedly healthy brother of the first proband was found to have borderline IQ, mild spasticity, and ataxia but no evidence of motor neuron disease. Marked cerebellar atrophy was detected by head scans in all three patients. In both probands electromyograms were characterized by prominent, complex repetitive discharges in many muscles. Hexosaminidase A activities against the artificial substrate were similar to those reported in infantile Tay-Sachs disease; however, the hexosaminidase A level against GM2 substrates was higher than that found in infantile Tay-Sachs disease. The hexosaminidase A levels of the parents were in the heterozygous range. Motor neuron disease in our patients and in those previously described appears to be part of a multisystem degeneration of the nervous system.
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PMID:Motor neuron disease and adult hexosaminidase A deficiency in two families: evidence for multisystem degeneration. 315 34

A progressive spinocerebellar degenerative disorder was characterized in nine patients, aged 11 to 37 years, from four unrelated Ashkenazi Jewish families; affected individuals had markedly deficient beta-hexosaminidase A activity. Symptoms included early onset of cerebellar signs (tremor, incoordination, and dysarthia) and, with maturity, the development of upper and lower motor neuron disorders, marked dysarthia, and ataxia. Three older patients, aged 26, 32, and 37 years, had dementia or recurrent psychotic episodes. Membrane-bound lamellar cytoplasmic inclusions, consistent with lysosomal ganglioside accumulation, were observed in rectal ganglia. The activity of beta-hexosaminidase A was markedly deficient in all sources analyzed. Parents had activities consistent with heterozygosity, confirming autosomal-recessive transmission of the beta-hexosaminidase A-deficient gene and the adult variant disorder. Residual beta-hexosaminidase A activity, partially purified by anion-exchange chromatography from cultured skin fibroblasts of the affected individuals, was heat-labile and co-electrophoresed with normal beta-hexosaminidase A. These findings suggest that these patients were allelic for a new beta-hexosaminidase A mutation and may represent a genetic compound of this allele and the allele causing Tay-Sachs disease.
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PMID:Chronic GM2 gangliosidosis masquerading as atypical Friedreich ataxia: clinical, morphologic, and biochemical studies of nine cases. 645 83

A 3-year-old boy developed progressive neurological deterioration in his third year, characterized by dementia, ataxia, myoclonic jerks, and bilateral macular cherry-red spots. Hexosaminidase A (HEX A) was partially decreased in the patient's serum, leukocytes, and cultured skin fibroblasts. Hexosaminidase was studied in serum and leukocytes from family members. Four members of the paternal branch appeared to be carriers of classical infantile Tay-Sachs allele, HEX alpha 2, probably receiving the gene from one great-grandparent of Ashkenazi origin. In the maternal branch, no one was a carrier of classical infantile Tay-Sachs disease, but five individuals were carriers of a milder alpha-locus defect. The patient, therefore, was a genetic compound of two different alpha-locus hexosaminidase mutations. At least 21 families with late-infantile or juvenile GM2 gangliosidosis have been reported, 18 of them with alpha-locus mutations, and three with beta-locus mutations. Genetic compounds of hexosaminidase have been reported in at least seven families, five with alpha-locus mutations and two with beta-locus mutations. The compound had the phenotype of infantile Tay-Sachs disease in one family, infantile Sandhoff disease in another, and the normal phenotype in the rest.
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PMID:Alpha-locus hexosaminidase genetic compound with juvenile gangliosidosis phenotype: clinical, genetic, and biochemical studies. 677 23

A significant number of major neurogenetic diseases have been defined at the molecular level in recent years, making it possible to determine precisely the genotype for familial Alzheimer's disease, Huntington's disease, Machado-Joseph disease, dominantly inherited ataxia, Charcot-Marie-Tooth disease, myotonic muscular dystrophy, Duchenne-Becker muscular dystrophy, familial amyotrophic lateral sclerosis, and neurofibromatosis. This information has made it possible to identify the abnormal genotype of at-risk persons for these diseases and for at-risk pregnancies for several of them. Precise molecular diagnoses are thus possible using applied molecular markers. Prevention of disease can be achieved using these molecular markers with genetic counseling and appropriate family planning. Significant progress is being made in this regard with Tay-Sachs disease, Huntington's disease, the dominantly inherited ataxias, and the muscular dystrophies. Further, this molecular genotyping will be of indispensible value to families with these diseases when somatic cell gene therapy becomes available. The field of molecular neurogenetics is moving forward rapidly, and advances in gene identification for these diseases will lead in the near future to the means to prevent many of them.
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PMID:The prevention of neurogenetic disease. 771 Mar 70

We have generated mouse models of human Tay-Sachs and Sandhoff diseases by targeted disruption of the Hexa (alpha subunit) or Hexb (beta subunit) genes, respectively, encoding lysosomal beta-hexosaminidase A (structure, alpha) and B (structure, beta beta). Both mutant mice accumulate GM2 ganglioside in brain, much more so in Hexb -/- mice, and the latter also accumulate glycolipid GA2. Hexa -/- mice suffer no obvious behavioral or neurological deficit, while Hexb -/- mice develop a fatal neurodegenerative disease, with spasticity, muscle weakness, rigidity, tremor and ataxia. The Hexb -/- but not the Hexa -/- mice have massive depletion of spinal cord axons as an apparent consequence of neuronal storage of GM2. We propose that Hexa -/- mice escape disease through partial catabolism of accumulated GM2 via GA2 (asialo-GM2) through the combined action of sialidase and beta-hexosaminidase B.
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PMID:Dramatically different phenotypes in mouse models of human Tay-Sachs and Sandhoff diseases. 878 34

Tay-Sachs disease is a genetically determined neurodegenerative disorder, resulting from mutations of the hexosaminidase (Hex) A gene coding for the alpha-subunit of beta-D-N-acetyl-hexosaminidase. Clinically, there is severe encephalomyelopathy leading to death within the first few years of life. Hex A activity is usually absent in tissue and body fluids of these patients. Juvenile and adult Hex A deficiencies are less severe but rare variants with some residual Hex A activity. All these variants are most prevalent among Ashkenazi Jews. We describe a non-Jewish family in which four adult brothers and sisters had markedly reduced Hex A activities and onset of symptoms in the second decade of life. The phenotypical expression was remarkably homogeneous, consisting in a combination of slowly progressive motor neuron disease, ataxia and ocular motor disturbances. None of the patients were demented at this stage of their illness. Magnetic resonance studies showed severe cerebellar atrophy, but were otherwise normal. Hex A deficiency was established by biochemical measurements in the serum and skin fibroblasts using the fluorogenic substrates 4-MUG and 4-MUGS as well as by gel electrophoresis. Molecular genetic studies revealed that the patients are compound heterozygotes for the 'adult' mutation Gly269 --> Ser and the 'infantile' 4-base insertion in exon 11 of the Hex A gene.
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PMID:Progressive cerebellar ataxia, proximal neurogenic weakness and ocular motor disturbances: hexosaminidase A deficiency with late clinical onset in four siblings. 907 25


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