Doença de Tay-Sachs: relato de caso / Tay-Sachs disease: a case report

RESUMO A doença de Tay-Sachs é um distúrbio neurodegenerativo autossômico recessivo, o qual envolve o metabolismo dos lipídios, levando ao acúmulo de gangliosídeos nos tecidos, devido à deficiência da enzima hexosaminidase A. Esse depósito progressivo resulta em perda da função neurológica e, quando acomete as células ganglionares da mácula, causa o achado típico da doença, a "mácula em cereja". A patologia é diagnosticada por meio dos níveis de hexosaminidase A e hexosaminidase total no soro, além análise do DNA do gene HEXA. Este caso relata uma criança com doença de Tay-Sachs cujo diagnóstico foi suspeitado por conta dos achados oftalmológicos.

ABSTRACT Tay-Sachs Disease is an autosomal recessive neurodegenerative disorder, which involves the metabolism of lipids, leading to the accumulation of gangliosides in the tissues, due to the deficiency of the enzyme Hexosaminidase A. This progressive deposit results in loss of neurological function and, when it affects macula ganglion cells, it causes the typical disease finding, the "cherry red spot". The pathology is diagnosed through the levels of Hex A and total Hexosaminidase in the serum, in addition to the analysis of the DNA of the HEXA gene. This case reports a child with Tay-Sachs disease with a suspected diagnosis was through ophthalmologic findings.

Enfermedad de Tay-Sachs / Tay-Sachs disease

La enfermedad de Tay-Sachs es un trastorno neurodegenerativo progresivo de herencia autosómica recesiva. Se debe a la deficiencia de la enzima β-hexosaminidasa A, que provoca una acumulación de gangliósidos GM2 en los lisosomas. Se incluye dentro de las esfingolipidosis. De las esfingolipidosis que presentan mancha rojo cereza en la mácula, la enfermedad de Tay-Sachs es la única en la que no se evidencia hepatoesplenomegalia. La variante más frecuente se inicia en la lactancia. Se presenta un lactante del sexo masculino al que se le realizó el diagnóstico de esta entidad a los 8 meses de edad. A partir de los 4 meses comenzó a presentar una reacción de sobresalto. A los 6 meses comenzó a perder habilidades previamente adquiridas y crisis epilépticas mioclónicas. Se constató una disminución de la actividad específica de la enzima hexosaminidasa A en leucocitos.

Tay-Sachs disease is a progressive autosomal recessive inherited neurodegenerative disorder caused by Beta-hexosaminidase A enzyme deficiency that in turn provokes GM2 ganglioside accumulation in the lysosomes. It is included in the sphyngolipidoses classification. Among the sphyngolipidoses that present with cherry-red spot in the macula, Tay-Sachs disease is the only one that does not show hepatosplenomegaly. The most frequent variant begins at the breast-feeding phase. This report presented a male nursling who was diagnosed with Tay-Sachs disease at the age of 8 months. At 4 months of age, he had begun getting some fright reactions. At 6 months-old, he began losing his previously acquired skills and suffering myoclonic seizures. The cause was the reduced specific activity of the hexosaminidase A enzyme in leukocytes.

Clinical and molecular characteristics of a child with juvenile Sandhoff disease / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore the clinical features and molecular mutation of HEXB gene in a case with juvenile Sandhoff disease.</p><p><b>METHOD</b>We retrospectively reviewed the clinical, neuroimaging and biochemical findings in this Chinese child with juvenile Sandhoff disease. Hexosaminidase A and hexosaminidase A & B activities were measured in blood leukocytes by fluorometric assay. HEXB gene molecular analysis was performed by PCR and direct sequencing.</p><p><b>RESULT</b>The 9-year-old boy was admitted for psychomotor regression. He presented slowly progressive gait disorder and dysarthria during the last three years. Cranial MRI revealed a marked cerebellar atrophy with normal intensity in the thalamus and basal ganglia. Brain MRS showed normal in the thalamus and basal ganglia. Hexosaminidase A was 69.5 (mg·h) [normal controls 150-360 nmol/(mg·h)], hexosaminidase A & B activity was 119 nmol/(mg·h)[normal controls 600-3 500 nmol/(mg·h)], confirming the diagnosis of Sandhoff disease. The patient was a compound heterozygote for a novel deletion mutation c.1404delT (p. P468P fsX62) and a reported mutation c.1509-26G>A.</p><p><b>CONCLUSION</b>The clinical features of juvenile Sandhoff disease include ataxia, dysarthria and cerebellar atrophy. The enzyme assay and molecular analysis of HEXB gene can confirm the diagnosis of Sandhoff disease. The novel mutation c.1404delT(p. P468P fsX62) is a disease-related mutation.</p>

Tay-sachs disease among the arabs

We report on a three-year-old Kuwaiti boy with the aim of making pediatricians and geneticists aware of the clinical and biochemical findings of infantile Tay-Sachs disease [TSD] in Arab populations. It is essential that there is no delay in establishing the diagnosis in order to ensure appropriate genetic counseling. The boy was first evaluated when he was 17 months old with profound hypotonia and significant global developmental delay and he died at the ago of three years. The clinical and biochemical findings of this patient are compared with other reported Arab cases to illustrate that TSD exists amongst Arabs with an unknown incidence and probably is more common than thought previously. There isa need for additional research to delineate molecular phenotypes of this disorder in Arabs and to offer carrier detection especially in high-risk families

Molecular cloning, sequence identification and tissue expression profile of three novel sheep (Ovis aries) genes - BCKDHA, NAGA and HEXA

The complete coding sequences of three sheep genes- BCKDHA, NAGA and HEXA were amplified using the reverse transcriptase polymerase chain reaction (RT-PCR), based on the conserved sequence information of the mouse or other mammals. The nucleotide sequences of these three genes revealed that the sheep BCKDHA gene encodes a protein of 313 amino acids which has high homology with the BCKDHA gene that encodes a protein of 447 amino acids that has high homology with the Branched chain keto acid dehydrogenase El, alpha polypeptide (BCKDHA) of five species chimpanzee (93 percent), human (96 percent), crab-eating macaque (93 percent), bovine (98 percent) and mouse (91 percent). The sheep NAGA gene encodes a protein of 411 amino acids that has high homology with the alpha-N-acetylgalactosaminidase (NAGA) of five species human (85 percent), bovine (94 percent), mouse (91 percent), rat (83 percent) and chicken (74 percent). The sheep HEXA gene encodes a protein of 529 amino acids that has high homology with the hexosaminidase A(HEXA) of five species bovine (98 percent), human (84 percent), Bornean orangután (84 percent), rat (80 percent) and mouse (81 percent). Finally these three novel sheep genes were assigned to GenelDs: 100145857, 100145858 and 100145856. The phylogenetic tree analysis revealed that the sheep BCKDHA, NAGA, and HEXA all have closer genetic relationships to the BCKDHA, NAGA, and HEXA of bovine. Tissue expression profile analysis was also carried out and results revealed that sheep BCKDHA, NAGA and HEXA genes were differentially expressed in tissues including muscle, heart, liver, fat, kidney, lung, small and large intestine. Our experiment is the first to establish the primary foundation for further research on these three sheep genes.

An Anesthetic Experience in a Patient with Tay-Sachs Disease : A case report / 대한마취과학회지

Tay-Sachs Disease (TSD), the most common form of GM(2) gangliosidosis, is an autosomal recessive inborn lysosomal glycosphingolipid storage disease which is resulted from the mutations that affect the alpha-subunit locus on chromosome 15 and cause a severe deficiency of hexosaminidase A. It is characterized by normal motor development in the first few months of life, followed by progressive weakness and loss of motor skills beginning around 6 months of life. Neurodegeneration is relentless and manifested as relentless motor and mental deterioration, beginning with motor incoordination, mental obtundation leading to muscular flaccidity, blindness, and increasing dementia, with death occurring by the age of 4 or 5 years. We report a successful anesthetic management in a patient with Tay-Sachs Diseases for tracheostomy and feeding gastrostomy.

A case of Niemann-Pick disease type A / 소아과

Niemann-Pick disease is a group of autosomal recessive disorders associated with hepatosplenomegaly, variable neurologic deficits, and the storage of sphingomyelin and other lipids. Seven cases have been reported in Korea. We report an additional case presenting with hypotonia, early neurodevelopmental delay, hepatosplenomegaly and death by persistent pneumonia and asphyxia at the age of 23 months. MRI of brain and fundoscopic findings of our case at 4 months of age were normal. However, abnormal intensity of the thalamus and atrophy of the right temporal lobe on the MRI and macular cherry red spots were noticed at the age of 17 months. A bone marrow biopsy showed large foamy cells, while hexosaminidase A and B levels were normal. Although biochemical or molecular workup was not done, these findings led to the diagnosis of infantile onset Niemann-Pick disease, probably type A. A brief review of the related literatures was made.

A Case of Tay-Sachs Disease in Korea Diagnosed by Enzyme Assay and DNA Analysis / 소아과

Tay-Sachs disease is an autosomal recessive, neurodegenerative disorder that results from excessive storage of the cell membrane glycolipid, and GM2 ganglioside within the lysosomes of cells. This disease is caused by deficiency of the isoenzyme beta-hexosaminidase A, produced in the endoplasmic reticulum. Patients with Tay-Sachs disease are characterized by normal motor development in the first few months of life, followed by progressive weakness and loss of motor skills beginning around 2 to 6 months of life. Neurodegeneration is relentless, with death occurring by the age of 4 or 5 years. Tay-Sachs disease could be diagnosed by hexosaminidase enzyme assay and DNA analysis of HEXA gene. However, specific treatment has not been developed. We report here on a case of Tay- Sachs disease in 18-month-old male who presented with delayed development and seizure. This patient showed hyperacusis and cherry red spot in macula on examination of the fundus. The hexosaminidase A activity was zero percent in the enzymatic assay and DNA analysis identified a mutation that glutamine is substituted by stop codon at position 390(Q390X). This patient is the first case of Tay-Sachs disease in Korea diagnosed by enzymatic assay and DNA analysis.

Studies on the molecular mechanism of GM(2) gangliosidosis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the molecular mechanism of GM(2) gangliosidosis.</p><p><b>METHODS</b>The skin fibroblasts from 4 patients with GM(2) gangliosidosis were subjected to culture. Enzyme activities assay, Western blot and immunocytochemical analysis were performed using the cultured fibroblasts.</p><p><b>RESULTS</b>The hexosaminidase (Hex) activities of 4 patients with GM(2) gangliosidosis were significantly decreased. The activities were 12% 3% 15% and 6% of control values, respectively. Western blot analysis indicated that the amount of Hex mature alpha- and beta- subunits (alpha m, beta m) was decreased in cells from patients 2 and 3, but only decreased alpha m was found in patient 1 and both alpha m and beta m were normal in cells from patient 4. Immunocytochemical analysis revealed the accumulated GM(2) ganglioside in cells from patients 1-4.</p><p><b>CONCLUSION</b>The pathogenesis of GM(2) gangliosidosis was associated with deficiency of Hex alpha m and beta m and GM(2) activator caused by HEXA, HEXB and GM(2)A gene mutations.</p>

Progressive Myoclonus Epilepsy Associated with Macular Cherry-Red Spots

Myoclonus, generalized epilepsy, and progressive neurological decline characterize progressive myoclonus epilepsy. A 25-year-old woman was admitted for the evaluation of seizure, progressive myoclonus and ataxic gait. Her symptoms had developed since she was 13 years old. She did not have facial dysmorphism, hepatosplenomegaly, or dementia. Fundoscopic evaluation revealed cherry-red spots in both macular regions. Biochemical assays of hexosaminidase A, beta-galactosidase, and neuraminidase in leukocytes and urine mucopolysaccharides were free of any abnormality. The patient might have an unknown type of lysosomal storage disease.

GM2 gangliosidoses: a review of cases confirmed by beta-N-acetylhexosaminidase assay.

The inborn errors of GM2 ganglioside metabolism cause GM2 ganglioside to accumulate within the lysosomes of the nerve cells. The majority of the patients are infants with the Tay-Sachs form of the disease associated with a severe deficiency of beta-N-Acetylhexosaminidase A (hexosaminidase A). Both Hexosaminidase A and B are deficient in Sandhoff disease. The serum total hexosaminidase and the percentage of hexosaminidase A and B were estimated in 449 patients who presented with progressive mental-motor retardation. Three cases of Tay-Sachs disease and two cases of Sandhoff disease were detected. They presented with exaggerated startle response to acoustic stimuli, seizures, optic atrophy and retinal cherry red spots in addition to psychomotor retardation. One case of Sandhoff disease had hepatosplenomegaly and skeletal deformities.

Enzyme studies in GM2 gangliosidiosis, and their application in prenatal diagnosis.

Assay of hexosaminidase A and B enzymes in four cases with developmental regression and cherry red spot on fundus examination confirmed that three cases had Tay-Sachs disease, and one case had Sandhoff disease. Prenatal diagnosis was carried out by hexosaminidase enzyme assay in amniotic fluid and cells in one family, and chorionic villus sample in the second family. The fetus was diagnosed to be unaffected in one, and affected in the other family. Assay of hexosaminidase A and B is useful for specific diagnosis of GM2 gangliosidosis, and for prenatal diagnosis to reduce the burden of these disorders.