Final answer:
Trinucleotide repeat expansion diseases are genetic disorders caused by the repetition of a three-nucleotide DNA sequence, leading to abnormal proteins. Examples include Huntington's disease, Myotonic dystrophy, Fragile X syndrome, Friedreich's ataxia, and Spinocerebellar ataxias.
Step-by-step explanation:
Trinucleotide repeat expansion diseases refer to a group of genetic disorders caused by the abnormal repetition of a triplet DNA sequence. This leads to the production of proteins with repeated amino acid sequences, which often results in the disruption of normal protein function. Below are some examples of trinucleotide expansion diseases:
- Huntington's disease - A neurodegenerative disorder characterized by motor disturbance, cognitive decline, and psychiatric issues.
- Myotonic dystrophy - A condition that affects muscle function and other systems in the body.
- Fragile X syndrome - The most common inherited cause of intellectual disability and autism.
- Friedreich's ataxia - A disease that causes progressive damage to the nervous system, resulting in symptoms ranging from gait disturbance and speech problems to heart disease.
- Spinocerebellar ataxias - A heterogeneous group of hereditary, progressive, degenerative disorders characterized by ataxia which affects gait and coordination.
Other conditions such as chronic granulomatous disease and congenital adrenal hyperplasia are caused by different genetic mutations that don't involve trinucleotide expansions.