Chromosome 15 represents more than 3% of the total DNA in cells.
|Summary:||Gene examples of chromosome 15:|
|Loss of several active genes in a specific region of chromosome 15, which contains the gene OCA2, results in Prader-Willi syndrome or Angelman syndrome. Prader-Willi syndrome occurs due to the deletion of the inherited paternal part of chromosome 15 or because of two copies of inherited maternal chromosome 15 with a lack of the paternal copy. Prader-Willi syndrome is characterized by weak muscle tone, poor growth and delayed development in infancy. Later it develops an insatiable appetite, chronic overeating, underdeveloped genitals and leads often to learning disabilities and behavioral problems. The Angelman syndrome affects the nervous system and occurs due to the|
deletion of the maternal region of chromosome 15. It can have manifold characteristics like delayed development, speech impairment, epilepsy or frequent laughter.
The OCA2 gene encodes a protein called P protein. It is believed to be involved in small molecule transport, specifically tyrosine, which is a precursor of melanin (melanin gives skin, hair and eyes their color). Mutations in OCA2 can result in type 2 oculocutaneous albinism, which is characterized by light colored hair and eyes, creamy white skin and problems with vision.