HTT gene
Commences mid-adult life
6% before age of 21 years.
Western European descent
Diagnosis:
-99% based on symptoms and family history.
-Genetic testing if there is no family history.
-Genetic testing detects carriers of the gene.
-95% at risk do not want testing
because there is no treatment.
-Chorionic villus sampling for prenatal diagnosis
Treatment for:
-Tetrabenzene
neuroleptics and benzodiazepines.
-Psychiatric symptoms.
- Eating difficulties - dysphagia
-Heart disease - causes 25% of fatalities.
-Suicide - third greatest cause of fatalities.
Prognosis:
Life expectancy = 20 years
life-threatening complications from muscle incoordination."