Sandhoff disease

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Sandhoff disease
Other namesSandhoff–Jatzkewitz disease, variant 0 of GM2-gangliosidosis or hexosaminidase A and B deficiency
Autosomal recessive - en.svg
Sandhoff disease is inherited via an autosomal recessive manner.
Specialty Endocrinology   OOjs UI icon edit-ltr-progressive.svg

Sandhoff disease is a lysosomal genetic, lipid storage disorder caused by the inherited deficiency to create functional beta-hexosaminidases A and B. [1] [2] These catabolic enzymes are needed to degrade the neuronal membrane components, ganglioside GM2, its derivative GA2, the glycolipid globoside in visceral tissues, [1] and some oligosaccharides. Accumulation of these metabolites leads to a progressive destruction of the central nervous system and eventually to death. [1] [3] The rare autosomal recessive [4] [5] neurodegenerative disorder is clinically almost indistinguishable from Tay–Sachs disease, another genetic disorder that disrupts beta-hexosaminidases A and S. There are three subsets of Sandhoff disease based on when first symptoms appear: classic infantile, juvenile and adult late onset.[ citation needed ]

Contents

Symptoms and signs

Sandhoff disease symptoms are clinically indeterminable from Tay–Sachs disease. The classic infantile form of the disease has the most severe symptoms and is incredibly hard to diagnose at this early age. [6] The first signs of symptoms begin before 6 months of age and the parents’ notice when the child begins regressing in their development. If the children had the ability to sit up by themselves or crawl they will lose this ability. This is caused by a slow deterioration of the muscles in the child’s body from the buildup of GM2 gangliosides. Since the body is unable to create the enzymes it needs within the central nervous system, it is unable to attach to these gangliosides to break them apart and make them non-toxic. With this buildup there are several symptoms that begin to appear such as muscle/motor weakness, sharp reaction to loud noises, blindness, deafness, inability to react to stimulants, respiratory problems and infections, mental retardation, seizures, cherry red spots in the retina, enlarged liver and spleen (hepatosplenomegaly), pneumonia, or bronchopneumonia. [7]

The other two forms of Sandhoff disease have similar symptoms but to a lesser extent. Adult and juvenile forms of Sandhoff disease are more rare than the infantile form. [8] In these cases victims suffer cognitive impairment (retardation) and a loss of muscle coordination that impairs and eventually destroys their ability to walk; the characteristic red spots in the retina also develop. The adult form of the disease, however, is sometimes milder, and may only lead to muscle weakness that impairs walking or the ability to get out of bed. [9]

Causes

Two parents carrying a mutated gene and passing it on to their offspring cause the disease. Even with both parents carrying the disease in their genome, there is only a 25% chance that they will have a child containing the genetic coding for the disease (see figure right). [10]

Each form of the disease is caused by the differences in the various mutations of the genome, in particular the codons on the 14 exons in the HEX B gene located within chromosome 5 (see figure bottom), leading to the differences in severities of the symptoms. [6] The difference in the codons has the consequence of inhibiting two enzymes located in the lysosomes of the neurons of the central nervous system. Lysosomes contain various enzymes to break down byproducts and toxins to ensure they do not accumulate enough to interfere with the function of the central nervous system. [7]

Using restriction enzymes, it was discovered that a mutation on chromosome 5 particularly within the C1214T allele caused the adult onset form of Sandhoff Disease. For the patient showing symptoms of the infantile or juvenile form they have a mutation on exon I207V from their father, and a 16 base pair deletion from their mother which can be located on as many as five exons, exons 1–5. [11] Hexb.jpg

Mutations and polymorphism

Articles regarding Sandhoff disease frequencies among distinct groups of people contain discrepancies from one another. More than 25 mutations have been reported other than novel mutations. [5]

One article says that Sandhoff disease is found commonly in individuals with a non-Jewish descent. [12]

Others say that it is more commonly in:

Discovery of several mutations in Ashkenazi Jews may reflect ascertainment bias rather than a high population frequency, because Ashkenazi Jews were the targeted population in a mass screening program for Tay-Sachs disease. Several rare SD mutations were discovered as researchers resolved cases of enzyme deficiency among suspected TSD carriers, but no cases of the disease itself have been reported. [5] [15]

However, since it is an autosomal recessive disease, it is likely found in any ethnic group passing from generation to generation through carriers without being expressed in their offspring. Even though the family may not have a history of Sandhoff disease, it is possible for two individuals to have a child with the disease. Since Sandhoff disease was only discovered in 1968, there are years the disease has gone undetected because of misdiagnoses.[ citation needed ]

Pathophysiology

Biallelic pathogenic variants in the HEXB gene cause Sandhoff disease. The gene provides instructions for making a protein crucial to the enzymes beta-hexosaminidase A and beta-hexosaminidase B, [16] which function in nerve cells to break down fatty substances, complex sugars, and molecules that are linked to sugars. In particular, beta-hexosaminidase A breaks down a fatty compound called GM2 ganglioside. Mutations in the HEXB gene disrupt the activity of these enzymes, preventing the breakdown of GM2 ganglioside and other molecules.[ citation needed ]

As a result, progressive damage caused by the resulting buildup of GM2 ganglioside leads to the destruction of nerve cells, causing the signs and symptoms associated with Sandhoff disease.[ citation needed ]

Diagnosis

Sandhoff disease can be detected through the following procedures (before it is apparent through physical examination): a biopsy removing a sample of tissue from the liver, genetic testing, molecular analysis of cells and tissues (to determine the presence of a genetic metabolic disorder), enzyme assay, and occasionally a urinalysis to determine if the above-noted compounds are abnormally stored within the body. For a child to suffer from this disease, both parents must be carriers, and both must transmit the mutation to the child. Thus, even in the case where both parents have the mutation, there is only a 25 percent chance their child will inherit the condition. Frequently, parents are given the opportunity to have a DNA screening if they are at high risk, to determine their carrier status before they have children. However, it is also highly recommended to undergo testing even for those parents who do not have a family history of Sandhoff disease. Over 95% of the families that have children with Sandhoff disease had no known prior family history of the condition, as the mutation in the HEXB gene does not cause clinical symptoms when only one copy is present, and often passed undetected from one generation to the next [6] Naturally, if an individual carries the mutation, he or she has a risk of transmitting it to the unborn child. Genetic counseling is recommended for those who have the mutation.[ citation needed ]

It is possible for parents who are about to have a child or had a child with Sandhoff Disease can have a PGD or PEGD. PEGD is pre-embryonic genetic diagnosis for the parents that would not benefit from a pre-implantation genetic diagnosis because of their religion or negative attitude for the discarding of embryos. PEGD sequences the genome of the embryo to be produced by two parents if they were to conceive a child. If the family has a history of Sandhoff disease it is recommended they have their genome sequenced to ensure they are not carriers or to sequence the genome of their child. [17]

Types

There are three types of Sandhoff disease: classic infantile, juvenile, and adult late onset. [16] Each form is classified by the severity of the symptoms as well as the age at which the patient shows these symptoms. [18]

Juvenile and adult onset forms of Sandhoff disease are very rare. Signs and symptoms can begin in childhood, adolescence, or adulthood and are usually milder than those seen with the infantile form of Sandhoff disease. As in the infantile form, mental abilities and coordination are affected. Characteristic features include muscle weakness, loss of muscle coordination (ataxia) and other problems with movement, speech problems, and mental illness. These signs and symptoms vary widely among people with late-onset forms of Sandhoff disease.[ citation needed ]

Treatment

Currently Sandhoff disease does not have any standard treatment and does not have a cure. However, a person suffering from the disease needs proper nutrition, hydration, and maintenance of clear airways. To reduce some symptoms that may occur with Sandhoff disease, the patient may take anticonvulsants to manage seizures or medications to treat respiratory infections, and consume a precise diet consisting of puree foods due to difficulties swallowing. Infants with the disease usually die by the age of 3 due to respiratory infections. The patient must be under constant surveillance because they can suffer from aspiration or lack the ability to change from the passageway to their lungs versus their stomach and their spit travels to the lungs causing bronchopneumonia. The patient also lacks the ability to cough and therefore must undergo a treatment to shake up their body to remove the mucus from the lining of their lungs. Medication is also given to patients to lessen their symptoms including seizures.[ citation needed ]

Currently the government is testing several treatments including N-butyl-deoxynojirimycin in mice, as well as stem cell treatment in humans and other medical treatments recruiting test patients. [11] A Sandhoff disease study showing proof of principle for gene therapy in a human model system using CRISPR and virus gene correction gives the chance for clinical trials to cure the disease. The ultra-rare occurrence is a main hurdle to overcome for clinical trials. [22] [23]

History

Sphingolipidoses Sphingolipidoses.svg
Sphingolipidoses

Sandhoff disease is one of several forms of what was formerly known as amaurotic idiocy. This inherited disease is characterized by the accumulation of lipid-containing cells in the viscera and in the nervous system, mental retardation, and impaired vision or blindness. The chemical and enzymatic analysis of various patients with amaurotic idiocy by Konrad Sandhoff (born 1939), a German biochemist, led to the identification of several biochemically distinct diseases: the first biochemical description of GM1-gangliosidosis in 1963, [24] Sandhoff disease in 1968, [1] Tay-Sachs-Disease, [2] [25] the AB-variant of GM2-Gangliosidosis [2] [26] and the B1-variant of GM2-gangliosidosis. [27]

The molecular defect in Sandhoff disease was discovered when Sandhoff studied the biochemistry of sphingolipids and gangliosides in the laboratory of Prof. Horst Jatzkewitz (1912–2002), a German biochemist (Max Planck Institute for Psychiatry, Munich). In October 1966, he obtained deep-frozen autopsy material from an infantile case with amaurotic idiocy. The glycolipid analysis soon demonstrated differences from all the cases studied before. Besides the neuronal storage of GM2, the storage of GA2 was much more pronounced, and different from all cases of Tay-Sachs disease studied so far, globoside accumulated in the visceral organs and, most importantly, hexosaminidase activity was almost completely absent. The disease causing catabolic enzyme deficiency of hexosaminidases was demonstrated with four different substrates (p–nitrophenyl-β-D-N-acetylglucosaminide, p-nitrophenyl-β-D-N-acetylgalactosaminide, glycolipid [3H]GA2 and [3H]globoside) in four different organs and published in 1968. [1]

See also

Related Research Articles

<span class="mw-page-title-main">Tay–Sachs disease</span> Human medical condition

Tay–Sachs disease is a genetic disorder that results in the destruction of nerve cells in the brain and spinal cord. The most common form is infantile Tay–Sachs disease, which becomes apparent around the age of three to six months of age, with the baby losing the ability to turn over, sit, or crawl. This is then followed by seizures, hearing loss, and inability to move, with death usually occurring by the age of three to five. Less commonly, the disease may occur in later childhood or adulthood. These forms tend to be less severe, but the juvenile form typically results in death by age 15.

<span class="mw-page-title-main">Gaucher's disease</span> Medical condition

Gaucher's disease or Gaucher disease (GD) is a genetic disorder in which glucocerebroside accumulates in cells and certain organs. The disorder is characterized by bruising, fatigue, anemia, low blood platelet count and enlargement of the liver and spleen, and is caused by a hereditary deficiency of the enzyme glucocerebrosidase, which acts on glucocerebroside. When the enzyme is defective, glucocerebroside accumulates, particularly in white blood cells and especially in macrophages. Glucocerebroside can collect in the spleen, liver, kidneys, lungs, brain, and bone marrow.

<span class="mw-page-title-main">Lysosomal storage disease</span> Medical condition

Lysosomal storage diseases are a group of over 70 rare inherited metabolic disorders that result from defects in lysosomal function. Lysosomes are sacs of enzymes within cells that digest large molecules and pass the fragments on to other parts of the cell for recycling. This process requires several critical enzymes. If one of these enzymes is defective due to a mutation, the large molecules accumulate within the cell, eventually killing it.

<span class="mw-page-title-main">Ganglioside</span> Class of chemical compounds

A ganglioside is a molecule composed of a glycosphingolipid with one or more sialic acids linked on the sugar chain. NeuNAc, an acetylated derivative of the carbohydrate sialic acid, makes the head groups of gangliosides anionic at pH 7, which distinguishes them from globosides.

<span class="mw-page-title-main">Neuronal ceroid lipofuscinosis</span> Medical condition

Neuronal ceroid lipofuscinosis is the general name for a family of at least eight genetically separate neurodegenerative lysosomal storage diseases that result from excessive accumulation of lipopigments (lipofuscin) in the body's tissues. These lipopigments are made up of fats and proteins. Their name comes from the word stem "lipo-", which is a variation on lipid, and from the term "pigment", used because the substances take on a greenish-yellow color when viewed under an ultraviolet light microscope. These lipofuscin materials build up in neuronal cells and many organs, including the liver, spleen, myocardium, and kidneys.

<span class="mw-page-title-main">GM2-gangliosidosis, AB variant</span> Medical condition

GM2-gangliosidosis, AB variant is a rare, autosomal recessive metabolic disorder that causes progressive destruction of nerve cells in the brain and spinal cord. It has a similar pathology to Sandhoff disease and Tay–Sachs disease. The three diseases are classified together as the GM2 gangliosidoses, because each disease represents a distinct molecular point of failure in the activation of the same enzyme, beta-hexosaminidase. AB variant is caused by a failure in the gene that makes an enzyme cofactor for beta-hexosaminidase, called the GM2 activator.

A lipid storage disorder is any one of a group of inherited metabolic disorders in which harmful amounts of fats or lipids accumulate in some body cells and tissues. People with these disorders either do not produce enough of one of the enzymes needed to metabolize and break down lipids or, they produce enzymes that do not work properly. Over time, the buildup of fats may cause permanent cellular and tissue damage, particularly in the brain, peripheral nervous system, liver, spleen, and bone marrow.

<span class="mw-page-title-main">Sphingolipidoses</span> Medical condition

Sphingolipidoses are a class of lipid storage disorders or degenerative storage disorders caused by deficiency of an enzyme that is required for the catabolism of lipids that contain ceramide, also relating to sphingolipid metabolism. The main members of this group are Niemann–Pick disease, Fabry disease, Krabbe disease, Gaucher disease, Tay–Sachs disease and metachromatic leukodystrophy. They are generally inherited in an autosomal recessive fashion, but notably Fabry disease is X-linked recessive. Taken together, sphingolipidoses have an incidence of approximately 1 in 10,000, but substantially more in certain populations such as Ashkenazi Jews. Enzyme replacement therapy is available to treat mainly Fabry disease and Gaucher disease, and people with these types of sphingolipidoses may live well into adulthood. The other types are generally fatal by age 1 to 5 years for infantile forms, but progression may be mild for juvenile- or adult-onset forms.

The GM2 gangliosidoses are a group of three related genetic disorders that result from a deficiency of the enzyme beta-hexosaminidase. This enzyme catalyzes the biodegradation of fatty acid derivatives known as gangliosides. The diseases are better known by their individual names: Tay–Sachs disease, AB variant, and Sandhoff disease.

The GM1 gangliosidoses, usually shortened to GM1, are gangliosidoses caused by mutation in the GLB1 gene resulting in a deficiency of beta-galactosidase. The deficiency causes abnormal storage of acidic lipid materials in cells of the central and peripheral nervous systems, but particularly in the nerve cells, resulting in progressive neurodegeneration. GM1 is a rare lysosomal storage disorder with a prevalence of 1 to every 100,000 to 200,000 live births worldwide, although rates are higher in some regions.

<span class="mw-page-title-main">Hexosaminidase</span> Class of enzymes

Hexosaminidase is an enzyme involved in the hydrolysis of terminal N-acetyl-D-hexosamine residues in N-acetyl-β-D-hexosaminides.

<span class="mw-page-title-main">HEXB</span> Protein-coding gene in the species Homo sapiens

Beta-hexosaminidase subunit beta is an enzyme that in humans is encoded by the HEXB gene.

In medical genetics, compound heterozygosity is the condition of having two or more heterogeneous recessive alleles at a particular locus that can cause genetic disease in a heterozygous state; that is, an organism is a compound heterozygote when it has two recessive alleles for the same gene, but with those two alleles being different from each other. Compound heterozygosity reflects the diversity of the mutation base for many autosomal recessive genetic disorders; mutations in most disease-causing genes have arisen many times. This means that many cases of disease arise in individuals who have two unrelated alleles, who technically are heterozygotes, but both the alleles are defective.

<span class="mw-page-title-main">GM2A</span> Mammalian protein found in Homo sapiens

GM2 ganglioside activator also known as GM2A is a protein which in humans is encoded by the GM2A gene.

<span class="mw-page-title-main">HEXA</span> Protein-coding gene in the species Homo sapiens

Hexosaminidase A (alpha polypeptide), also known as HEXA, is an enzyme that in humans is encoded by the HEXA gene, located on the 15th chromosome.

<span class="mw-page-title-main">Galactosialidosis</span> Rare disease

Galactosialidosis, also known as neuraminidase deficiency with beta-galactosidase deficiency, is a genetic lysosomal storage disease. It is caused by a mutation in the CTSA gene which leads to a deficiency of enzymes β-galactosidase and neuraminidase. This deficiency inhibits the lysosomes of cells from functioning properly, resulting in the accumulation of toxic matter within the cell. Hallmark symptoms include abnormal spinal structure, vision problems, coarse facial features, hearing impairment, and intellectual disability. Because galactosialidosis involves the lysosomes of all cells, it can affect various areas of the body, including the brain, eyes, bones, and muscles. Depending on the patient's age at the onset of symptoms, the disease consists of three subtypes: early infantile, late infantile, and juvenile/adult. This condition is considered rare, with most cases having been in the juvenile/adult group of patients.

A pseudodeficiency allele or pseudodeficiency mutation is a mutation that alters the protein product or changes the gene's expression, but without causing disease. For example, in the lysosomal storage diseases, patients with a pseudodeficiency allele show greatly reduced enzyme activity, yet they remain clinically healthy.

Substrate reduction therapy offers an approach to treatment of certain metabolic disorders, especially glycogen storage diseases and lysosomal storage disorders. In a storage disorder, a critical failure in a metabolic pathway prevents cellular breakdown and disposal of some large molecule. If residual breakdown through other pathways is insufficient to prevent harmful accumulation, the molecule accumulates in the cell and eventually interferes with normal biological processes. Examples of lysosomal storage disorders include Gaucher's disease, Tay–Sachs disease, Sandhoff disease, and Sanfilippo syndrome.

For preventing Tay–Sachs disease, three main approaches have been used to prevent or reduce the incidence of Tay–Sachs disease in those who are at high risk:

<span class="mw-page-title-main">History of Tay–Sachs disease</span>

The history of Tay–Sachs disease started with the development and acceptance of the evolution theory of disease in the 1860s and 1870s, the possibility that science could explain and even prevent or cure illness prompted medical doctors to undertake more precise description and diagnosis of disease. Waren Tay and Bernard Sachs, two physicians of the late 19th century described the progression of the disease precisely and provided differential diagnostic criteria to distinguish it from other neurological disorders with similar symptoms.

References

  1. 1 2 3 4 5 Sandhoff K, Andreae U, Jatzkewitz H (March 1968). "Deficient hexosaminidase activity in an exceptional case of Tay-Sachs disease with additional storage of kidney globoside in visceral organs". Life Sci. 7 (6): 283–8. doi:10.1016/0024-3205(68)90024-6. PMID   5651108.
  2. 1 2 3 Sandhoff K (August 1969). "Variation of beta-N-acetylhexosaminidase-pattern in Tay-Sachs disease". FEBS Lett. 4 (4): 351–354. doi: 10.1016/0014-5793(69)80274-7 . PMID   11947222. S2CID   84542601.
  3. Pilz H, Müller D, Sandhoff K, ter Meulen V (September 1968). "Tay-Sachssche Krankheit mit Hexosaminidase-Defekt (Klinische, morphologische und biochemische Befunde bei einem Fall mit viszeraler Speicherung von Nierenglobosid)". Dtsch Med Wochenschr. 93 (39): 1833–9. doi:10.1055/s-0028-1110836. PMID   5679107.
  4. Harzer K, Sandhoff K, Schall H, Kollmann F (November 1971). "Enzymatische Untersuchungen im Blut von Überträgern einer Variante der Tay-Sachsschen Erkrankung (Variante 0)". Klin Wochenschr. 49 (21): 1189–91. doi:10.1007/bf01732464. PMID   5124584. S2CID   1735733.
  5. 1 2 3 Online Mendelian Inheritance in Man (OMIM): Sandhoff Disease - 268800
  6. 1 2 3 4 Gomez-Lira M, Sangalli A, Mottes M, Perusi C, Pignatti PF, Rizzuto N, Salviati A (1995). "A common β hexosaminidase gene mutation in adult Sandhoff disease patients". Human Genetics. 96 (4): 417–422. doi:10.1007/bf00191799. PMID   7557963. S2CID   39688704.
  7. 1 2 "Introduction to Sandhoff Disease". The Medical Biochemistry Page. Retrieved 2009-05-03.
  8. "Sandhoff Disease". Genetics Home Reference. Retrieved 2009-05-03.
  9. "Symptoms of Sandhoff Disease". Medical Books Excerpts. Lippincott Williams & Wilkin. 2008.
  10. 1 2 Lowden JA, et al. (1978). "Carrier detection in Sandhoff disease". American Journal of Human Genetics. 30 (1): 338–345. PMC   1685463 . PMID   414620.
  11. 1 2 "Lysosomal Diseases Testing Laboratory". Department of Neurology Jefferson Hospital. Archived from the original on April 10, 2009. Retrieved 2009-05-03.
  12. "Carrier Testing". National Tay-Sachs & Allied Disease Association, Inc. Retrieved 2009-05-03.
  13. Kleiman FE, et al. (1994). "Sandhoff disease in Argentina: high frequency of a splice site mutation in the HEXB gene and correlation between enzyme and DNA-based tests for heterozygote detection". Human Genetics. 94 (3): 279–82. doi:10.1007/bf00208283. PMID   8076944. S2CID   9666991.
  14. Drousiotou A, et al. (2000). "Sandhoff disease in Cyprus: population screening by biochemical and DNA analysis indicates a high frequency of carriers in the Maronite community". Human Genetics. 107 (1): 12–17. doi:10.1007/s004390050003. PMID   10982028.
  15. Cantor RM, Kaback MM (1985). "Sandhoff disease (SHD) heterozygote frequencies (HF) in North American (NA) Jewish (J) and non-Jewish (NJ) populations: implications for carrier (C) screening". American Journal of Human Genetics. 37: A48.
  16. 1 2 Chamoles NA, Blanco M, Gaggioli D, Casentini C (April 2002). "Tay-Sachs and Sandhoff diseases: enzymatic diagnosis in dried blood spots on filter paper: retrospective diagnoses in newborn-screening cards". Clinica Chimica Acta. 318 (1–2): 133–7. doi:10.1016/S0009-8981(02)00002-5. PMID   11880123.
  17. Kuliev A, Rechitsky S, Laziuk K, Verlinsky O, Tur-Kaspa I, Verlinsky Y (2006). "Pre-Embryonic diagnosis for Sandhoff Disease". Reproductive BioMedicine Online. 12 (3): 328–333. doi:10.1016/S1472-6483(10)61005-X. PMID   16569321.
  18. Zhang, Zhi-Xin; Nobuaki Wakamatsu; Emilie H. Mulesi; George H. Thomasi; Roy A. Gravel (1994). "Impact of premature stop codons on mRNA levels in infantile Sandhoff disease". Human Molecular Genetics. 3 (1): 139–145. doi:10.1093/hmg/3.1.139. PMID   8162015.
  19. "From a parents perspective: Parents view of Sandhoff". sandhoffdisease.webs.com. Archived from the original on 2009-01-29. Retrieved 2009-05-03.
  20. Hendriksz CJ, Corry PC, Wraith JE, Besley GT, Cooper A, Ferrie CD (2004). "Juvenile Sandhoff disease-Nine New Cases and a review of the literature". Journal of Inherited Metabolic Disease. 27 (2): 241–9. doi:10.1023/B:BOLI.0000028777.38551.5a. PMID   15159655. S2CID   41447979.
  21. Karbani, Gulshan A (15 May 2012). "Genetic Counselling: Consanguinity and Cultural Expectations". Encyclopedia Of Life Sciences. doi:10.1002/9780470015902.a0006179.pub2. ISBN   978-0470016176.
  22. Allende, Maria L.; Cook, Emily K.; Larman, Bridget C.; Nugent, Adrienne; Brady, Jacqueline M.; Golebiowski, Diane; Sena-Esteves, Miguel; Tifft, Cynthia J.; Proia, Richard L. (2018-01-22). "Cerebral organoids derived from Sandhoff disease induced pluripotent stem cells exhibit impaired neurodifferentiation". Journal of Lipid Research. 59 (3): 550–563. doi:10.1194/jlr.M081323. ISSN   0022-2275. PMC   5832932 . PMID   29358305. Archived from the original on 2018-02-23. Retrieved 2018-02-23.
  23. "Sandhoff disease study shows proof of principle for gene therapy - Scienmag: Latest Science and Health News". Scienmag: Latest Science and Health News. 2018-02-22. Retrieved 2018-02-23.
  24. Jatzkewitz H, Sandhoff K (June 1963). "On a biochemically special form of infantile amaturotic idiocy". Biochim Biophys Acta. 70: 354–6. doi:10.1016/0006-3002(63)90764-9. PMID   13957544.
  25. Okada S, O'Brien JS (August 1969). "Tay-Sachs disease: generalized absence of a beta-D-N-acetylhexosaminidase component". Science. 165 (894): 698–700. Bibcode:1969Sci...165..698O. doi:10.1126/science.165.3894.698. PMID   5793973. S2CID   8473726.
  26. Conzelmann E, Sandhoff K (August 1978). "AB variant of infantile GM2 gangliosidosis: deficiency of a factor necessary for stimulation of hexosaminidase A-catalyzed degradation of ganglioside GM2 and glycolipid GA2". Proc Natl Acad Sci U S A. 75 (8): 3979–83. Bibcode:1978PNAS...75.3979C. doi: 10.1073/pnas.75.8.3979 . PMC   392913 . PMID   99746.
  27. Kytzia HJ, Hinrichs U, Maire I, Suzuki K, Sandhoff K (1983). "Variant of GM2-gangliosidosis with hexosaminidase A having a severely changed substrate specificity". EMBO J. 2 (7): 1201–5. doi:10.1002/j.1460-2075.1983.tb01567.x. PMC   555256 . PMID   6226523.

This article incorporates some public domain text from The U.S. National Library of Medicine