File talk:Autosomal dominant inheritance.jpg
From Embryology
Huntington’s Disease
- polyglutamine trinucleotide repeat expansion disease
- chromosome 4p16.3
- protein called huntingtin
- Cytosine Adenine Guanine (CAG) repeats in the first exon
- up to 28 repeats - normal range
- 29-34 repeats - individual will not develop HD, next generation at risk
- 40 or more repeats - individual will develop HD
- repeat enlargement occurs during spermatogenesis
- reduced brain mass and basal ganglia atrophy (caudate nucleus, putamen, internal and external regions of the globus pallidus (GPi and GPe)
