Editing Tay–Sachs disease (section)

== Signs and symptoms ==
Tay–Sachs disease is typically first noticed in infants around 6 months old displaying an abnormally strong response to sudden noises or other stimuli, known as the "startle response". There may also be listlessness or muscle stiffness (hypertonia). The disease is classified into several forms, which are differentiated based on the onset age of [[neurological]] [[symptom]]s.<ref name="NINDS">{{Cite web |date=14 February 2007 |title=Tay–Sachs disease Information Page |url=http://www.ninds.nih.gov/disorders/taysachs/taysachs.htm |url-status=dead |archive-url=https://web.archive.org/web/20111127080325/http://www.ninds.nih.gov/disorders/taysachs/taysachs.htm |archive-date=27 November 2011 |access-date=10 May 2007 |publisher=[[National Institute of Neurological Disorders and Stroke]]}}</ref><ref name="omimtaysachs">{{Cite web |last1=McKusick |first1=Victor A |last2=Hamosh |first2=Ada |title=Online Mendelian Inheritance in Man |url=http://omim.org/entry/272800 |url-status=live |archive-url=https://web.archive.org/web/20160104022642/http://omim.org/entry/272800 |archive-date=4 January 2016 |access-date=24 April 2009 |publisher=United States National Institutes of Health}}</ref>

=== Infantile ===
[[Infant]]s with Tay–Sachs disease appear to develop normally for the first six months after [[childbirth|birth]]. Then, as [[neuron]]s become distended with GM2 gangliosides, a relentless [[Genetic deterioration|deterioration]] of mental and physical abilities begins. The child may become [[Blindness|blind]], [[deaf]], unable to [[Swallowing|swallow]], [[atrophy|atrophied]], and [[paralysis|paralytic]]. Death usually occurs before the age of four.<ref name="NINDS" />

=== Juvenile ===
Juvenile Tay–Sachs disease is rarer than other forms of Tay–Sachs and usually is initially seen in children between two and ten years old. People with Tay–Sachs disease experience [[cognitive]] and [[motor skill]] deterioration, [[dysarthria]], [[dysphagia]], [[ataxia]], and [[spasticity]].<ref>{{Cite journal |vauthors=Specola N, Vanier MT, Goutières F, Mikol J, Aicardi J |date=1 January 1990 |title=The juvenile and chronic forms of GM2 gangliosidosis: clinical and enzymatic heterogeneity |journal=Neurology |volume=40 |issue=1 |pages=145–150 |doi=10.1212/wnl.40.1.145 |pmid=2136940 |s2cid=19301606}}</ref> Death usually occurs between the ages of five and fifteen years.<ref name=Kur2016/>

=== Late-onset ===
A rare form of this disease, known as Adult-Onset or Late-Onset Tay–Sachs disease, usually has its first symptoms during the 30s or 40s. In contrast to the other forms, late-onset Tay–Sachs disease is usually not fatal as the effects can stop progressing. It is frequently misdiagnosed. It is characterized by unsteadiness of [[gait]] and progressive neurological deterioration. Symptoms of late-onset Tay–Sachs&nbsp;– which typically begin to be seen in [[adolescence]] or early [[adult]]hood&nbsp;– include [[speech]] and swallowing difficulties, unsteadiness of gait, spasticity, cognitive decline, and psychiatric illness, particularly a [[schizophrenia]]-like [[psychosis]].<ref name="LOTS1">{{Cite journal |vauthors=Rosebush PI, MacQueen GM, Clarke JT, Callahan JW, Strasberg PM, Mazurek MF |year=1995 |title=Late-onset Tay–Sachs disease presenting as catatonic schizophrenia: Diagnostic and treatment issues |journal=Journal of Clinical Psychiatry |volume=56 |issue=8 |pages=347–53 |pmid=7635850}}</ref> Late-onset Tay–Sachs patients may become fully [[wheelchair]]-bound.<ref>{{Cite journal |last1=Lyn |first1=Nicole |last2=Pulikottil-Jacob |first2=Ruth |last3=Rochmann |first3=Camille |last4=Krupnick |first4=Robert |last5=Gwaltney |first5=Chad |last6=Stephens |first6=Nick |last7=Kissell |first7=Julie |last8=Cox |first8=Gerald F. |last9=Fischer |first9=Tanya |last10=Hamed |first10=Alaa |date=2020-04-15 |title=Patient and caregiver perspectives on burden of disease manifestations in late-onset Tay-Sachs and Sandhoff diseases |journal=Orphanet Journal of Rare Diseases |volume=15 |issue=1 |pages=92 |doi=10.1186/s13023-020-01354-3 |issn=1750-1172 |pmc=7160997 |pmid=32295606 |doi-access=free}}</ref>

Until the 1970s and 1980s, when the disease's molecular genetics became known, the juvenile and adult forms of the disease were not always recognized as variants of Tay–Sachs disease. Post-infantile Tay–Sachs was often misdiagnosed as another neurological disorder, such as [[Friedreich's ataxia]].<ref>{{Cite journal |author-link5=Robert J. Desnick |vauthors=Willner JP, Grabowski GA, Gordon RE, Bender AN, Desnick RJ |date=July 1981 |title=Chronic GM2 gangliosidosis masquerading as atypical Friedreich's ataxia: Clinical, morphologic, and biochemical studies of nine cases |journal=Neurology |volume=31 |issue=7 |pages=787–98 |doi=10.1212/wnl.31.7.787 |pmid=6454083 |s2cid=27305940}}</ref>