Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content ++ 330.1 Cerebral lipidoses ++ E75.02 Tay-Sachs disease ++ 5B: Impaired Neuromotor Development +++ Description ++ Progressive autosomal recessive genetic disorderInfant lacks protein, beta-hexosaminidase A that prevents the accumulation of the lipid, ganglioside GM-2, thus causing damage to brain cells. +++ Essentials of Diagnosis ++ Genetic defect of chromosome 15 +++ General Considerations ++ Categories:Infantile: most commonSymptoms appear between 3 to 6 months of age.Juvenile: Symptoms begin between 2 to 5 years old.Adult: Symptoms begin during adolescence or as young adult. +++ Demographics ++ Carrier ratesAshkenazi Jewish: 1/272Total population: 1/2503French Canadian, Louisiana Cajun, and Ashkenazi Jewish: 1/273British Isles or Irish: range between 1/50 to 1/1503Equally affects males and females +++ Signs and Symptoms ++ DeafnessBlindnessLoss of gag reflexDifficulty swallowingMuscle weaknessHypotoniaDementiaIrritabilitySeizuresParalysisRegression in gross motor and fine motor skillsCherry-red spot on eyes +++ Possible Contributing Causes ++ Progressive autosomal recessive genetic disorderBoth parents must carry the defective Tay-Sachs gene, the child has a 25% chance of developing the disease +++ Differential Diagnosis ++ Gaucher diseaseNiemann-Pick diseaseDanshoff diseaseHepatosplenomegaly +++ Functional Implications ++ Progressive muscle weakness resulting in decline in gross and fine motor skills such as inability to sit, ambulate or feed self +++ Laboratory Tests ++ Blood test for hexosaminidase levels +++ Diagnostic Procedures ++ DNA analysis ++ GeneticistNeurologistOphthalmologistSpeech pathologist ++ Inability to rollInability to commando crawl or creep on hands and kneesInability to sitInability to ambulate ++ Early intervention developmental profileNeonatal behavioral assessment scalePediatric evaluation of disability inventoryManual muscle test ++ Developmental activities to:Prevent loss of motor milestonesPrevent loss of muscle strengthTherapeutic exercise to:Prevent muscle contracturesStrengthenStretchFunctional activitiesTransfersGait trainingStair climbing ++ Sit supported in adaptive chair for 15 minutes during play activities in 1 month.Prevent loss of range of motion to allow for optimal positioning within 3 months.Take steps in a gait trainer to allow for independent mobility and upright function within 4 months.Transfer from wheelchair to/from classroom chair with moderate assistance in 6 months. ++ Infantile form: Child life expectancy is between 4 or 5 years old.1 ++1. American Physical Therapy Association. Interactive Guide to Physical Therapy Practice. Atlanta: American Physical Therapy Association; 2003. http://guidetoptpractice.apta.org. Accessed October 21, 2011. ++2. Tay-Sachs Disease. A.D.A.M. Encyclopedia. PubMed Health. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002390/. Accessed December 3, 2011. +... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth