Review Note

Last Update: 10/14/2024 05:22 AM

Current Deck: Genes and Development::Week 2::LE016 Non-Mendelian Inheritance Part 2

Published

Pathogenesis for trinucleotide repeat disorders

Class 1: diseases due to the expansion of {{c1::noncoding repeats}} that cause a {{c1::haploinsufficiency}} by impairing transcription of the preRNA from the affected gene. Examples: Fragile X syndrome and Friedreich ataxia.
Class 2: disorders resulting from expansions of {{c1::noncoding repeats}} that confer {{c1::novel properties on the RNA}}. Examples: Myotonic Dystrophy 1 and 2, fragile X–associated tremor/ataxia syndrome.
Class 3: diseases due to repeat expansion of {{c1::a codon (such as CAG for glutamine)}} that confers {{c1::novel properties on the affected protein}}. Examples: Huntington disease, the spinocerebellar ataxias.