Final answer:
Minisatellites and microsatellites are types of repeating DNA sequences used for DNA fingerprinting. Abnormal changes can cause diseases, such as expansions in the FMR1 gene's CGG repeat sequence leading to Fragile X syndrome, a genetic disorder with cognitive impairments.
Step-by-step explanation:
Minisatellites and microsatellites are both types of repeating sequences found in DNA. Minisatellites, also known as variable number tandem repeats (VNTRs), consist of a short DNA sequence repeated 10-60 times, while microsatellites, or short tandem repeats (STRs), are shorter DNA sequences consisting of 2-6 base pairs repeated 5-50 times. These satellite DNA sequences are distributed throughout the genome and are highly variable between individuals, making them useful for DNA fingerprinting and forensic analysis.
Changes in the number of repeats in these sequences can cause diseases. For example, expansions of a trinucleotide microsatellite repeat sequence of CGG in the FMR1 gene causes Fragile X syndrome, a genetic disorder associated with intellectual disability and other cognitive impairments.
Fragile X syndrome is a clear example of how changes in microsatellite DNA can lead to disease. In patients with Fragile X, the CGG repeat is abnormally expanded, which silences the gene and prevents the production of a protein necessary for normal neural development.