Macrosatellites are the largest of the
tandem DNA repeats. Each macrosatellite repeat typically is several
kilobase
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DN ...
s in length, and the entire repeat array often spans hundreds of kilobases.
Reduced number of repeats on chromosome 4 (D4Z4 repeats) causes
euchromatization of local DNA and is the predominant cause of
facioscapulohumeral muscular dystrophy
Facioscapulohumeral muscular dystrophy (FSHD) is a type of muscular dystrophy, a group of heritable diseases that cause degeneration of muscle and progressive weakness. Per the name, FSHD tends to sequentially weaken the muscles of the face, ...
(FSHD).
Other macrosatellites are RS447, NBL2 and
DXZ4,
although RS447 is also commonly referred to as a "megasatellite."
See also
*
Microsatellite
*
Minisatellite
A minisatellite is a tract of repetitive DNA in which certain DNA motifs (ranging in length from 10–60 base pairs) are typically repeated 5-50 times. Minisatellites occur at more than 1,000 locations in the human genome and they are notable for ...
*
Satellite DNA Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. Satellite DNA is the main component of functional centromeres, and form the main structural constituent of heterochromatin.
The name "satellite DNA" refers to the ...
References
Genetics
Repetitive DNA sequences
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