Rev. Fac. Med. 2019 Vol. 67 No. 3: 511-7 511 REVIEW ARTICLE DOI: http://dx.doi.org/10.15446/revfacmed.v67n3.69742 Tay-Sachs disease Enfermedad de Tay-Sachs Received: 10/01/2018. Accepted: 14/06/2018. Carlos Andrés Gualdrón-Frías1 • Laura Tatiana Calderón-Nossa1 1 Universidad Pedagógica y Tecnológica de Colombia - Tunja Campus - Faculty of Health Sciences - School of Medicine - ACEMED-UPTC Research Group - Tunja - Colombia Corresponding author: Carlos Andrés Gualdrón-Frías. Grupo de Investigación ACEMED-UPTC, Facultad de Ciencias de la Salud, Universidad Pedagógica y Tecnológica de Colombia. Calle 24 No. 5-63, antiguo Hospital San Rafael de Tunja. Phone number: +57 8 7405626, ext.: 2908. Tunja. Colombia. Email: [email protected]. | Abstract | | Resumen | Introduction: Lysosomal storage disease is caused by the deficiency Introducción. La deficiencia de una sola hidrolasa (enzimas lisosomales) of a single hydrolase (lysosomal enzymes). GM2 gangliosidoses da como resultado una enfermedad de almacenamiento lisosomal. Las are autosomal recessive disorders caused by deficiency of gangliosidosis GM2 son trastornos autosómicos recesivos causados β-hexosaminidase and Tay-Sachs disease (TSD) is one of its three por la deficiencia de β-hexosaminidasa. La enfermedad de Tay-Sachs forms. (TSD, por sus siglas en inglés) es una de las tres presentaciones de este tipo de gangliosidosis. Objective: To perform a review of the state of the art on TSD and describe its definition, epidemiology, etiology, physiopathology, Objetivo. Realizar una revisión del estado del arte de la TSD describiendo clinical manifestations, as well as advances regarding its diagnosis su definición, epidemiología, etiología, fisiopatología, manifestaciones and treatment. clínicas y actualidades en su diagnóstico y tratamiento. Materials and methods: A literature search was carried out in Materiales y métodos. Se realizó una búsqueda bibliográfica en PubMed using the MeSH terms “Tay-Sachs Disease”. PubMed utilizando como único término MeSH “Tay-Sachs Disease”. Results: after the initial search was conducted, 1 233 results were Resultados. Se encontraron 1 233 publicaciones y se seleccionaron retrieved, of which 53 articles were finally selected. TSD is caused by 53 artículos. La TSD es originada por la deficiencia de la enzima the deficiency of the lysosomal enzyme β-hexosaminidase A (HexA), lisosomal β-hexosaminidasa A (HexA) y se caracteriza por regresión and is characterized by neurodevelopmental regression, hypotonia, del neurodesarrollo, hipotonía, hiperacusia y manchas maculares rojo hyperacusis and cherry-red spots in the macula. Research on molecular cereza. La investigación de la patogenia molecular y el desarrollo pathogenesis and the development of possible treatments has been de posibles tratamientos han sido limitados y en la actualidad no se limited, consequently there is no treatment established to date. cuenta con uno plenamente establecido. Conclusion: TSD is an autosomal recessive neurodegenerative Conclusiones. La TSD es un trastorno neurodegenerativo autosómico disorder. Death usually occurs before the age of five. More research recesivo y por lo general la muerte se produce antes de los 5 años de and studies on this type of gangliosidosis are needed in order to find edad. Son necesarias más investigaciones y estudios sobre este tipo an adequate treatment. de gangliosidosis con el fin de encontrar un tratamiento adecuado. Keywords: Tay-Sachs Disease; Gangliosidoses; Hexosaminidase Palabras clave: Enfermedad de Tay-Sachs; Gangliosidosis GM2; A; Enzymes; Jews (MeSH). Hexosaminidasa A; Enzimas; Judíos (DeCS). Gualdrón-Frías CA, Calderón-Nossa LT. Tay-Sachs Gualdrón-Frías CA, Calderón-Nossa LT. [Enfermedad de Disease. Rev. Fac. Med. 2019;67(3):511-7. English. doi: Tay-Sachs]. Rev. Fac. Med. 2019;67(3):511-7. English. doi: http://dx.doi.org/10.15446/revfacmed.v67n3.69742. http://dx.doi.org/10.15446/revfacmed.v67n3.69742. Introduction of only one of these hydrolases results in the inability to degrade macromolecules and, as a consequence, a lysosomal storage disease. Lysosomes contain a wide variety of active hydrolytic enzymes known (1) GM2 gangliosidoses are autosomal recessive disorders caused by as hydrolases, including glycosidases, phosphatases, sulphatases, the deficiency of β-hexosaminidase, which in turn lead to excessive lipases, proteases, phospholipases, and nucleases. (1) Deficiency intralyosomal accumulation, particularly in neuronal cells. (1,2) 512 Tay-Sachs disease: 511-7 There are two isoenzymes of β-hexosaminidase: hexosaminidase community due to its rare nature. With this in mind, the objective A (HexA), a heterodimer formed by two subunits (α and β), and of this research is to provide information so that it can be a useful hexosaminidase B (HexB), a homodimer also formed by two subunits tool to know and understand this pathology for proper diagnose (β- and β). (1,3) There are also three forms of GM2 gangliosidosis: and treatment. In this article, the reader will find information on Tay-Sachs disease (TSD), Sandhoff disease (SD) and GM2 activator the epidemiology, etiology, physiopathology, clinical, diagnosis and deficiency. (1) Specifically, this article describes TSD, which is caused management of this disease. by the deficiency of the HexA subunit α. (4) TSD was first described in 1881, but its etiology remained unknown Materials and methods for a long time, and affected newborns could only be diagnosed after the first clinical manifestations. (1,5) That changed in 1969 when the A literature search was made in PubMed using the MeSH term “Tay- deficiency of the hexosaminidase enzymatic activity was discovered, Sachs Disease”, obtaining 1 237 results in total. Citations were filtered, allowing the initiation of the assessment of carrier states. (5-6) Large- according to study type, in case reports, clinical trials, controlled scale detection in specific ethnic groups decreased its incidence by clinical trials, narrative reviews, meta-analyses, systematic reviews, 90% in the USA, mainly in groups where the rate of the disease was letters to the editor, classical articles, editorials, historical articles and higher, as in people of Ashkenazi Jewish descent. (5) For this reason, journal articles, and also according to language (English), obtaining Tay-Sachs disease is considered a prototype disease for targeted ethnic 666 results. evaluations. (5) The search was conducted in December 2017 and was filtered by TSD occurs most often in children with intellectual disability, skill date of publication, without exceeding five years, retrieving in 45 results. regression, dementia, paralysis and blindness, and it, usually, leads to Eight of the references were beyond the search and date range as they death by age 5. (7) If an individual is Jewish —or even if s/he has a were original publications of the first findings of the disease; however, Jewish grandparent—, is aged between 18 and 44 years old and plans those articles included MRI observations or clinical manifestations to have children, the probability that they have the disease is 1 in 3 of importance that contained information relevant to the review and 100 live births. (8,9) deserved to be included. Recent technological advances and demographic changes are A total of 53 articles were selected, and their abstracts were read modifying the way professionals study and explore TSD. A research in their entirety. In addition, a book bibliography was included since by Lazarin et al. (10) reveals that 40% of TSD carriers in their cohort this information allows clarifying important epidemiological data. were from non-targeted ethnic groups. (10) In addition, marriages Figure 1 shows the flow chart of the review articles. between different ethnic groups result in more complex genetic diversity, so a traditional DNA analysis has low sensitivity (5); Results however, sequencing promises greater sensitivity and specificity, with the potential to become a leading tool in carrier state screening Of the 54 sources used to carry out the literarure review, 53 were and thus increasing its effectiveness to further decrease the incidence articles and 1 was a book. Among the 53 articles, 31 were original of TSD. (5) investigations, 4 were narrative reviews, 9 were case reports, and 9 Having an updated literature review on TSD is of great importance, were letters to the editor. Table 1 provides a characterization of the since there is little relevant information available to the medical most significant documents for the study. Results of the PubMed search: 1 237 Articles excluded for not meeting the Results after ltering according to English language and date of publication study type: 666 requirement <5 years: 621 Articles whose titles met the selection criteria: 45 Documents included because of their Articles were included because of their relevance to the research objective: 54 relevance to the research objective: 8 Books included because of their relevance to the research objective: 1 Figure 1. Search flowchart. Source: Own elaboration. Rev. Fac. Med. 2019 Vol. 67 No. 3: 511-7 513 Table 1. Characterization of significant documents for the study. Definition Study Country Language Key findings TSD is an autosomal recessive, neurodegenerative disorder that is part Modulation of endoplasmic reticulum of a group of three lysosomal storage diseases known as gangliosidosis Dersh et al. quality control systems may be a GM2. (4,7,11) These diseases are caused by a defect in GM2- USA Englsih (4), 2016.