trinucleotide_repeat_disorders_flashcards
What are trinucleotide repeat disorders?
Genetic conditions caused by an abnormal number of repeats (expansions) of a repetitive sequence of three nucleotides.
What causes trinucleotide repeat disorders?
Expansions of a repetitive sequence of three nucleotides that are unstable and may enlarge.
What is the phenomenon called when the age of onset is earlier in successive generations?
Anticipation.
What is often noted along with the earlier age of onset in trinucleotide repeat disorders?
An increase in the severity of symptoms.
Give examples of trinucleotide repeat disorders.
Fragile X (CGG), Huntington’s (CAG), myotonic dystrophy (CTG), Friedreich’s ataxia (GAA), spinocerebellar ataxia, spinobulbar muscular atrophy, dentatorubral pallidoluysian atrophy.
Which trinucleotide repeat disorder does not demonstrate anticipation?
Friedreich’s ataxia.
