Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tay-Sachs”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2026

Cerebrospinal delivery of a bidirectional AAV9 vector improves optic nerve and retinal pathology in a sheep model of Tay-Sachs disease.

Tay-Sachs disease (TSD) is a fatal neurodegenerative lysosomal storage disease. The Jacob sheep is the only large-animal model of TSD, yet ocular pathology and the therapeutic potential of gene therapy remain poorly defined. Sheep cohorts included normal controls (n = 3); untreated TSD-affected (n = 4); intravenous AAV9-Bic_HexA/HexB-treated (n = 3); and intracerebroventricular, cisterna magna, and lumbar intrathecal AAV9- Bic_HexA/HexB-treated sheep (cerebrospinal fluid [CSF] therapy; n = 7). Retinal histopathology and immunohistochemistry, retinal whole-mount analyses for retinal ganglion cell (RGC) morphology and density, optic nerve evaluation with p-phenylenediamine (PPD )semi-thin sections, qPCR assessment for vector genomes, and RNAscope probes for transgene expression were performed. Untreated TSD sheep exhibited RGCs with abundant microvesicular cytoplasmic expansion and optic nerve spheroids, with storage material variably staining with periodic acid-Schiff. Marked astrocytosis, microgliosis, and GM2 accumulation within RGCs were present. Optic nerve axon counts and RGC density were significantly reduced, and optic nerve damage scores increased, in untreated and IV-treated sheep but were rescued with short-term CSF therapy. GM2 volume and signal intensity per RGC were significantly reduced following short-term CSF therapy. Minimal but detectable retinal vector genomes and transgene expression were observed. These findings demonstrate retinal and optic nerve pathology in Jacob sheep with TSD and AAV9 therapy.

Animals↗
PubMed2025

Similarities and Differences in the Late-Onset GM2 Gangliosidoses: Tay-Sachs and Sandhoff Diseases.

The two predominating subtypes of late-onset GM2 gangliosidosis are late-onset Tay-Sachs (LOTS) and late-onset Sandhoff disease (LOSD). Due to shared deficiencies of ß-hexosamindase A and significant clinical overlap, the two diseases have been considered indistinguishable. However, a growing body of evidence supports the notion of several distinctions between the two diseases. In this study, we highlight these distinctions through the cross-sectional evaluation of 27 late-onset GM2 gangliosidosis participants. Twenty-one participants with LOTS and 6 with LOSD were included in this study. We performed physical examinations alongside assessments for gait, balance, muscle strength, ataxia, nerve conduction velocities, and analyzed brain magnetic resonance imaging. Lower limb weakness (95% in LOTS, 100% in LOSD) and later development of upper limb weakness (90% in LOTS, 83% in LOSD) was highly prevalent in both cohorts. Accompanying gait disturbances, balance issues, and dysmetria (as assessed by the brief ataxia rating scale [BARS]) were also prevalent in both cohorts. Strength testing for the quadriceps and hamstrings demonstrated weakness in both cohorts, primarily impacting extensor muscles. Supratentorial gray and white matter volumes in both cohorts were similar to normative data. In contrast, BARS scores for dysarthria and oculomotor dysfunction were present and heterogenous in LOTS participants and absent in LOSD participants. 24% of LOTS participants and none of the LOSD participants had a history of neuropsychiatric symptoms. Cerebellar volume including lobules V and VI were lower in LOTS compared to LOSD and normative data. However, length dependent sensory neuropathy was present in all LOSD participants but absent in LOTS participants. Dysfunction of the posterior cerebellum (lobules VI, VII, and IX) has been shown to cause cerebellar cognitive affective syndrome (CCAS), that includes cognitive and behavioral disturbances. Furthermore, cerebellar dysfunction of lobules V and VI has been linked to dysarthric speech, and dysfunction of the posterior cerebellum has been linked to oculomotor symptoms. The finding of low cerebellar lobule volumes in LOTS, suggests the distinctive features of the LOTS phenotype are related to cerebellar dysfunction. However, the sensory symptoms unique to LOSD remains a mystery. The molecular and biochemical basis for the dichotomy between the LOTS and LOSD phenotypes requires further investigation.

GM2 Gangliosidosis↗
PubMed1976

Identification of Tay-Sachs by hexosaminidase analysis of urine and tear samples.

1. Two readily obtainable biological fluids, i.e., urine and tears, were investigated as possible substitutes for serum and leukocytes for the detection of Tay-Sachs disease (TSD) heterozygotes based on Quantitative hexosaminidase A (Hex A) determinations. 2. Hexosaminidase isoenzyme patterns were determined, by means of an automated DEAE-cellulose microcolumn procedure, for serum, urine and tear samples from normals, TSD carriers, normal pregnancies, carrier-pregnancies and TSD children. 3. Normal pregnancy and TSD carrier sera gave almost identical hexosaminidase patterns with multiple intermediate peaks. Whereas, urine and tear samples from normal pregnant women showed hexosaminidase isoenzyme patterns resembling those of normal controls. These results suggested that use of these fluids might eliminate the effect of pregnancy of the Hex A ratio which occurs when serum is used as the test fluid. In addition these fluids are most economical and simpler to obtain than a blood sample. 4. About 200 urine samples, from the various categories listed above, were analyzed for Hex A with both the heat denaturation and pH inactivation methods and the results compared with serum and leukocyte levels from many of the same individuals. With either method, the wide overlap between the urinary Hex A normal and heterozygote ranges would require retesting with leukocytes of about 30% of the subjects. These results would preclude the use of urines as a suitable fluid for the mass screening of the Ashkenazic Jewish population for TSD heterozygotes.

Autoanalysis↗
PubMed1977

Ganglioside GM2 N-acetyl-beta-D-galactosaminidase and asialo GM2 (GA2) N-acetyl-beta-D-galactosaminidase; studies in human skin fibroblasts.

Ganglioside GM2 and its asialo-derivative, GA2 were radiolabeled in their N-acetyl-D-galactosaminyl moieties by oxidation with galactose oxidase and reduction with tritiated sodium borohydride. Specific activities of 6 X 10(4) dpm/nmol (GM2) and 1.8 X 10(6) dpm/nmol (GA2) were achieved. About 98% of the label was in N-acetyl-D-galactosamine. Using these substrates, an assay was developed for GM2-N-acetyl-beta-D-galactosaminidase (E.C.3.2.1.30) and GA2-N-acetyl-beta-D-galactosaminidase (E.C.3.2.1.30) activities in human cultured skin fibroblasts. The products of the GM2 cleaving reaction were identified as N-acetylgalactosamine and ganglioside GM3. Both GM2 and GA2 cleaving activities were stimulated about 5-fold by purified sodium taurocholate, and this stimulation was inhibited by neutral detergents, lipids and albumin at low concentrations. Addition of various salts, reducing agents and a protein activator factor from human liver of Li et al. (1973) did not stimulate GM2-N-acetyl-beta-D-galactosaminidase activity beyond that found with sodium taurocholate. Under optimal conditions, control fibroblast supernates cleaved ganglioside GM2 at a rate of 3.7 nmol/mg protein/h compared to 1100 for GA2-N-acetyl-beta-D-galactosaminidase and 4700 for 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminidase. Supernates from two patients with Tay-Sachs disease had markedly reduced activity levels for GM2-N-acetyl-beta-D-galactosaminidase but not for the other two substrates. Supernates from two patients with Sandhoff's disease had reduced activities for all three substrates. A supernate from one patient with juvenile GM2 gangliosidosis cleaved GM2 at a somewhat faster rate than those from Tay-Sachs or Sandhoff's patients. Two healthy adult women with markedly reduced hexosaminidase A activities using 4MU-N-acetyl-beta-D-glucosaminide as substrate had approximately half-normal activities using GM2 as substrate. A patient with the Tay-Sachs phenotype but with a partial deficiency of hexosaminidase A using the 4-MU substrate had a profound deficiency using GM2 as substrate. In such unusual hexosaminidase mutants, assays using GM2 as substrate are better indicators of phenotype than those using synthetic substrates.

Adult↗
PubMed2025

Dual-vector rAAVrh8 gene therapy for GM2 gangliosidosis: a phase 1/2 trial.

The dual rAAVrh8-HEXA and rAAVrh8-HEXB vector can restore central nervous system hexosaminidase (Hex) enzyme activity, decrease GM2 levels in cerebrospinal fluid and rescue phenotypic consequences of GM2 gangliosidosis, Tay-Sachs and Sandhoff diseases in animal models following simultaneous bi-thalamic (BiT) injections. Following up on an n = 2 expanded access trial, we initiated a phase 1/2, single-dose, dose-escalation of combined BiT, intra-cisterna magna and intrathecal infusion in children with Tay-Sachs and Sandhoff diseases (six infantile, three juvenile). The BiT injection volume and vector dose were doubled between four cohorts, with the lowest dose matching the earlier expanded access trial. Cerebrospinal fluid HexA enzyme activity, serum total Hex activity and GM2 levels showed a dose-dependent biochemical correction of the disease. Serum Hex activity surpassed 40 nmol h-1 ml-1, two times the lower limit of normal, and neuroimaging demonstrated increased fiber tracts. Correction was greatest at 12 weeks, but in decline by 24 weeks postdosing. Infantile patients experienced global clinical stabilization and prolonged oral feeding without aspiration until 3-3.5 years. Seizures had a later onset, were less frequent, less severe and more responsive to anti-convulsant medication. Adverse events were rare in infantile patients, but worsening dystonia was observed in juvenile patients, who were excluded from ongoing enrollment. ClinicalTrials.gov registration: NCT04669535 and NCT06614569 .

Humans↗
PubMed1975

Effect of hypocholesterolemic drug AY9944 on cultured nervous tissue: morphologic and biochemical studies.

The effects of different concentrations of the hypocholesterolemic drug AY9944, an inhibitor of delta7-reductase, on organotypic cultures of fetal mouse spinal cord, were studied by light and electron microscopy. Exposure to 10(-6)M produced no observable changes. After 6 hours exposure to 10(-4)M, dense membrane-bound inclusions were occasionally observed in neurons. After 24 hours exposure to 10(-4)M, numerous cytoplasmic inclusions occurred in neurons, glia and macrophages. The form of these inclusions varied but were predominantly of two types; concentric, loosely-packed lamellae resembling membranous cytoplasmic bodies (MCB) of Tay-Sachs disease and irregular dense bodies. They were identical to those observed in our previous in vivo study. Prolonged exposure to the drug at 10(-4)M caused an increased number of inclusions in all cell types. Eventually the cultures degenerated. The number of inclusions increased for at least 38 days following a 2-5 day exposure to AY9944 at 10(-4)M. However, by 70 days, although inclusions persisted, the cultures were mostly astrocytic. In long-term cultures, in addition to these inclusions, curved or straight electron-dense paired profiles were seen in some cells, presumably macrophages. Biochemical analysis of cultures exposed to 10(-4)M revealed the continuous presence of delta7, 24-cholesta-diene-3beta-ol and 7-dehydrocholesterol even after the drug wa removed from the cultures. In our previous animal experiments, intracytoplasmic inclusions and abnormal sterols with a double bond at the 7 position disappeared quickly after discontinuation of the drug. Therefore, the results obtained in our present in vitro experiments are different in this regard from the in vivo studies of AY9944.

Cholestadienols↗
PubMed1976

Characterization and tissue distribution of N-acetyl hexosaminidase C: suggestive evidence for a separate hexosaminidase locus.

1. An electrophoretic system in which N-acetyl hexosaminidase C (HEX(C)) MIGRATES LESS ANODALLY THAN N-acetyl hexosaminidase A (HEX(A)) is described. 2. HEX(C) is shown to differ from HEX(A) and HEX(B) in substrate specificity, molecular size and affinity for Concanavalin-A. 3. HEX(C) is present in a wide range of adult and foetal tissues and in tissues from patients with Tay-Sachs and Sandhoff's diseases. It is particularly prominent in brain, testis, thymus and lymphoblastoid cell extracts and in several foetal tissues. 4. It is suggested that HEX(C) is coded at a separate gene locus from HEX(A) and HEX(B).

Acetylglucosaminidase↗
PubMed1977

Enzymic detection of metachromatic leukodystrophy patients and heterozygotes.

Two unrelated families with metachromatic leukodystrophy have been examined for the leukocyte enzyme arylsufatase A. The enzyme activities clearly reflect an autosomal recessive mode of inherence. All four parents showed heterozygote enzyme levels 40-60 percent of the control range while the two affected children had less than 20 percent normal activity. The two sibs of one affected child were shown to be heterozygote carriers. A simple screening method for sulfatase activity in tears has been developed which distinguished between metachromatic leukodystrophy patients and a control population which included other neurological disorders. Enzyme screening on tears may also be used to detect other lysosomal storage diseases including Tay-Sachs and Fabry disease.

Adult↗
PubMed1975

[Differential diagnosis of congenital lipidoses by lipid analyses of body fluids, biopsy and autopsy tissue].

1. Presentation of the commomly used procedures for the extraction and separation of total lipids, glycolipids and phosholipids from fresh and formalin-fixed organs tissues (brain, liver, spleen, kidney) as well as from serum, CSF and urine. II. Description of the qualitative and quantitative analysis of individual lipid fractions (glycolipids, gangliosides, phospholipids, neutral lipids) by thin-layer chromatograhy and photodensitometry. III. Results of investigations performed on biopsy material, autopsy material, serum and urine in the following diseases: 1. Infantile, juvenile and adult Gaucher's disease: accumulation of glucocerebroside in liver and spleen. 2. Infantile and adult Niemann-Pick disease: accumulation of sphingomyelin in liver, spleen, kidney and lung. 3. Fabry's disease: increased urinary excretion of trihexosyl-ceramide and dihexosyl-ceramide. 4. Infantile and adult metachromatic leukodystrophy: accumulation of sulfatides in the central and peripheral nervous system and kidney, increased urinary excretion of sulfatides. 5. Austin's variant of metachromatic leukodystrophy: besides an increase of sulfatides in the white matter of brain accumulation of glycolipids in the cerebral cortex. 6. Tay-Sachs disease (GM2-gangliosidosis): cerebral accumulation of GM2-ganglioside and trihexosylceramide (enzyme variant B), additional visceral accumulation (liver, spleen, kidney) of tetrahexosyl-ceramide = globoside (enzyme variant 0). 7. Infantile generalized GM1-gangliosidosis: cerebral (and visceral) accumulation of GM1-ganglioside and tetrahexosyl-ceramide. 8. Late infantile GM1-gangliosidosis: Cerebral accumulation of GM1-ganlioside and tetrahexosylceramide. 9. GM3-gangliosidosis (lactosyl-ceramidosis): neuronal accumulation of lactosyl-ceramide, GM2-ganglioside and GM3-ganglioside. 10. Refsum's disease: demonstration of phytanic acid esters of cholesterol in serum.

Autopsy↗
PubMed1976

Ganglioside biosynthesis. Characterization of uridine diphosphate galactose: GM2 galactosyltransferase in golgi apparatus from rat liver.

An enzyme that transfers galactose from UDP-Gal to ganglioside GM2 (Tay-Sachs ganglioside) was concentrated 50 times in Golgi apparatus from rat liver relative to total homogenates. This enzyme required detergents or phospholipids as dispersing agents. Of the numerous detergents tested, sodium taurocholate and Triton CF-54 were most effective in stimulating the reaction. Cardiolipin alone was more effective than any of the detergents tested in stimulating enzyme activity. The pH optimum for the reaction varied with the nature of the dispersing agent. With sodium taurocholate, Triton CF-54 and cardiolipin, the pH optima were 6.2, 5.9, and 5.6, respectively. The enzyme had a nearly absolute requirement for Mn2+, with maximum activity being attained at a concentration of 15 mM Mn2+. Other divalent or trivalent cations were either less effective than Mn2+ or inhibited the transferase reaction. The Km values calculated for UDP-Gal and GM2 were 1.1 X 10(-4) M and 9.9 X 10(-5) M, respectively. The enzyme could not be dissociated from Golgi apparatus fractions by treatment with ultrasound, indicating that it is tightly associated with the membrane and not part of the luminal contents. The newly synthesized GM2, the product of the reaction, was incorporated into or became tightly associated with the membranes of the Golgi apparatus.

Animals↗