Anticipation (genetics)
In genetics, anticipation is the increasing severity or the earlier manifestation of a genetic disease in successive generations. It describes the earlier development of developmental characteristics of a generation compared to the previous generation. This occurs especially with trinucleotide diseases . An expansion of the unstable repeat mutation that causes the disease is seen as the cause. Using the example of Huntington's disease, an autosomal dominant inheritance , it can be seen that the number of CAG triplet repeats has increased compared to the parent generation.
Examples
- Chorea huntington
- Type 1 myotonic dystrophy
- Fragile X syndrome (Martin-Bell syndrome, Marker X syndrome)
- Autosomal dominant spinocerebellar ataxia