What is chromosome 17q12?

A chromosome 17q12 microdeletion means that a part of one of the body’s chromosomes has been lost or deleted. If the missing chromosome material contains genes with important instructions for the brain or body, developmental delay, some learning and behaviour difficulties, and health problems may occur.

What is 17q12 duplication syndrome?

17q12 duplication is a chromosomal change in which a small piece of chromosome 17 is copied (duplicated ) abnormally in each cell. The duplication occurs on the long (q) arm of the chromosome at a position designated q12.

What is chromosome duplication syndrome?

23 duplication syndrome is considered to be an autosomal dominant condition, which means one copy of chromosome 7 with the duplication in each cell is sufficient to cause the disorder. Most cases result from a duplication that occurs during the formation of reproductive cells (eggs and sperm).

What disease is caused by duplication?

Some people with MECP2 duplication syndrome may have autistic features, gastrointestinal problems, and/or mildly distinctive facial features. The syndrome is caused by having an extra copy (duplication) of the MECP2 gene , and inheritance is X-linked .

What causes trisomy17?

What causes trisomy 17 mosaicism? Trisomy 17 mosaicism occurs due to a random event during the formation of the reproductive cells (egg and sperm) or after fertilization has taken place. An error in cell division (called nondisjunction ) may cause some eggs or sperm to have an abnormal number of chromosomes.

How often does MECP2 duplication syndrome occur?

The prevalence of MECP2 duplication syndrome is unknown; more than 200 affected individuals have been described in the scientific literature. It is estimated that this condition is responsible for 1 to 2 percent of all cases of intellectual disability caused by changes in the X chromosome.