Initially he was suspected having taysachs disease and finally diagnosed as gm2 gangliosidosis, ab variant due to truncated protein caused by nonsense mutation c. Wed like to understand how you use our websites in order to improve them. Gm2 gangliosidosis variant 0 cag center for animal genetics. Gm2gangliosidosis, ab variant is a rare inherited disorder that progressively destroys nerve cells neurons in the brain and spinal cord.
Gm2 gangliosidoses an overview sciencedirect topics. For language access assistance, contact the ncats public information officer. Genetic and rare diseases information center gard po box 8126, gaithersburg, md 208988126 tollfree. In march 2001, the national institutes of health issued the following warning. The patient was a 14 months old black female infant who had black cherry spot in the retinas. Gm1 gangliosidosis is an inherited disorder that progressively destroys nerve cells neurons in the brain and spinal cord. Sandhoff disease with a deficiency of both hex a and hex b also called the o type. Gm2gangliosidosis, ab variant is a rare, autosomal recessive metabolic disorder that causes progressive destruction of nerve cells in the brain and spinal cord. Jul 11, 2016 gm2 gangliosidosis ab variants a rare autosomal recessive neurodegenerative disorder occurring due to deficiency of gm2 activator protein resulting from the mutation in gm2a gene. Mri of brain revealed putaminal hyperintensity and thalamic hypointensity with some unmyelinated white matter in t2t1 weighted images. Enable javascript to view the expandcollapse boxes. Gm2gangliosidosis, b, b1, ab variant genetic and rare. Gangliosidosis is caused by a deficiency in the enzyme acid betagalactosidase1.
This disorder known as taysachs disease tsd is concisely defined by omim online mendelian inheritance in man as an autosomal recessive, progressive neurodegenerative disorder, which in the classic infantile form, is usually fatal by age 2 or 3 years, results from deficiency of the enzyme hexosaminidase a. Gtr test id help each test is a specific, orderable test from a particular laboratory, and is assigned a unique gtr accession number. Okada and obrien 1968 demonstrated that betagalactosidase deficiency is the fundamental defect in generalized gangliosidosis. The molecule gm2 ganglioside, is shown here in the schematic. Gm2gangliosidosis, ab variant genetics home reference nih. The ab variant is caused by nonfunctional gm2 activator, the b variant by nonfunctional asubunit and 0 variant is caused by nonfunctional bsubunit. Gm1 gangliosidosis and morquio b disease are rare lysosomal storage disorders caused by deficiency of the. The ab variant form of gm2 gangliosidosis is an inherited lysosomal storage disease. Gangliosidosis 1 gm1 disease is caused by the absence or significantly reduced level of a vital enzyme called betagalactosidase glb1.
Gm2gangliosidosis, ab variant is a very rare form of gm2 gangliosidosis due to a deficiency of gm2 activator protein, associated with. The three major forms of gm2 gangliosidosis include taysachs disease and its variants due to a hex a deficiency also known as the b types. A total of six causative variants have been detected and include three missense, one nonsense, and two small deletions. Pathology of gm2 gangliosidosis in jacob sheep article pdf available in veterinary pathology 484. It is characterized by the accumulation of gm2 ganglioside in neurons that is caused by a lack of gm2 activator protein function. B variant gm2 gangliosidosis pronunciation in english. Gm1 gangliosidosis is a neurodegenerative condition with a phenotypic spectrum that has been classified into three main clinical forms based on onset age and severity. Biochemical characterization of the gm2 gangliosidosis b1 variant. Gangliosidosis contains different types of lipid storage disorders caused by the accumulation of lipids known as gangliosides. Sep 07, 2018 home medterms medical dictionary az list b variant gm2gangliosidosis definition medical definition of b variant gm2gangliosidosis medical author. More detailed information about the symptoms, causes, and treatments of gm2gangliosidosis, ab variant is available below. Infants with this disorder typically appear normal until the age of. Sequence analysis is expected to identify a variant on greater than 95% of glb1 alleles in patients with gm1gangliosidosis and morquio b with reduced or absent. Gm2gangliosidosis variant ab is inherited in an autosomal recessive manner and results from pathogenic variants in the gm2a gene schroder et al.
A collection of disease information resources and questions answered by our genetic and rare diseases information specialists for gm2gangliosidosis, b, b1, ab variant. Type iii shows extreme clinical variability, with some patients having only focal neurologic. The number of web sites offering healthrelated resources grows every day. This disorder is an autosomal recessive disease characterized by the lysosomal accumulation of glycoconjugates with terminal. A very rare inherited disorder where the brain and spinal cord nerve cells central nervous system are progressively destroyed. Ab variant gm2gangliosidosis a bibliography and dictionary for physicians, patients, and genome researchers philip m. The topic gm2 gangliosidosis type ii you are seeking is a synonym, or alternative name, or is closely related to the medical condition sandhoff disease. Ab variant gm2gangliosidosis a bibliography and dictionary. Signs and symptoms of the ab variant become apparent in infancy. Biochemical data have linked its cause to the lack of a functional gm2 activator protein activator. Test gm2gangliosidosis variant ab via the gm2a gene.
Infantile sandhoff disease has similar symptoms and prognosis, except that there is deficiency of both hexosaminidase a and hexosaminidase b. Gm1 gangliosidosis, or landing disease, is a rare inherited neurodegenerative lysosomal storage disorder characterized by severe cognitive and motor developmental delays resulting in the death of most patients at a very young age. Some researchers classify this condition into three major types based on the age at which signs and symptoms first appear. Gangliosidosis definition of gangliosidosis by medical. Present case is a one year old male born to 3rd degree consanguineous indian parents from maharashtra.
Clinical and neuropathological studies of a case of ab variant gm2gangliosidosis have been presented. This form of gm2 gangliosidosis is indistinguishable from infantile form of taysachs disease due to its phenotypic similarity. Gm2 gangliosidosis is also known as sandhoff disease or gm2 gangliosidosis variant 0. In addition, a book bibliography was included since. Signs and symptoms of gm2gangliosidosis, ab variant are identical with those of infantile taysachs disease, except that enzyme assay testing shows normal levels of hexosaminidase a. The third variant of gm2 gangliosidosis, known as ab variant omim272750, is rarely encountered and only nine cases are reported till date world wide as described in table 1 2, 56. Gm2gangliosidosis, ab variant genetics home reference. An autosomal recessive lysosomal storage disease marked by the accumulation of gm2 gangliosides in the neuronal cells.
Both are autosomal recessive and affect males and females equally. Gm2 gangliosidosis, ab variant is an extremely rare, severe genetic disorder characterized by progressive. Gangliosidosis genetic and rare diseases information center. More than 150 variants have been identified in the glb1 gene that occur throughout the gene. There are two distinct genetic causes of the disease. The topic variant 0 of gm2 gangliosidosis you are seeking is a synonym, or alternative name, or is closely related to the medical condition sandhoff disease. Bradbury et al neurodegenerative lysosomal storage disease in european burmese cats with hexosaminidase bsubunit deficiency, molecular genetics and metabolism, 2009. Sandhoff disease is a rare, inherited disorder autosomal recessive that occurs due to an enzyme deficiency. Without glb1, a fatty substance or lipid called gm1 ganglioside accumulates abnormally in cells, especially in the nerve cells of the brain.
If you have problems viewing pdf files, download the latest version of adobe reader. Only seven mutations in nine cases have been reported from different population except india. The disorder is less severe than gm1 gangliosidosis types i and ii. Gm2 activator deficiency gm2gangliosidosis ab variant hexosaminidase activator deficiency taysachs disease ab variant. Gm2 gangliosidosis is a family of heritable neurodegenerative diseases known as taysachs, sandhoff and the ab variant form, all of which results from gm2 ganglioside accumulation in neuronal cells. Type 3 gm1 gangliosidosis, which occurs in children or adults ages 3 to 30 years, is a slowly progressive disorder with dysarthria, dystonia, rigidity, bradykinesia, and gait abnormalities. It is characterized by gm2 gangliosides accumulation in the absence of hexa activity, leading to neurodegeneration and, in the infantile form, death in early childhood. A progressive neurodegenerative disorder that begins with muscle weakness, then progresses to startle reaction, retardation and seizures. Gm2 gangliosidosis, ab variant is a rare, autosomal recessive metabolic disorder that causes progressive destruction of nerve cells in the brain and spinal cord.
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