We have discussed several diseases associated with unstable trinucleotide repeats. Name three examples of these diseases and detail the technology that you would use to determine if an individual carried one or more defective genes. Identifying Trinucleotide Repeat Disorders with DNA Testing

Identifying Trinucleotide Repeat Disorders with DNA Testing

Trinucleotide repeat disorders (TRDs) are a group of genetic diseases caused by an expansion of trinucleotide repeats in specific genes. These repeats can cause a variety of neurological and neuromuscular disorders, and three of the most common TRDs are fragile X syndrome, myotonic dystrophy type 1, and Huntington’s disease. DNA testing is the most reliable way to determine if an individual carries one or more defective genes associated with these diseases. Fragile X syndrome is caused by an expansion of CGG trinucleotide repeats in the FMR1 gene, and is the most common inherited form of intellectual disability (Raymond et al., 2020). DNA testing for this disease involves amplifying the FMR1 gene to determine the number of CGG repeats and identify individuals who have the disease-causing mutation.
Myotonic dystrophy type 1 is caused by an expansion of a CTG trinucleotide repeat in the DMPK gene (Kapoor et al., 2017). DNA testing for this disease involves amplifying the DMPK gene to determine the number of CTG repeats and identify individuals who have the disease-causing mutation.
Huntington’s disease is caused by an expansion of CAG trinucleotide repeats in the HTT gene (Liu et al., 2021). DNA testing for this disease involves amplifying the HTT gene to determine the number of CAG repeats and identify individuals who have the disease-causing mutation. Cont…