What does the 20th chromosome do?

Chromosome 20 likely contains 500 to 600 genes that provide instructions for making proteins. These proteins perform a variety of different roles in the body.

What is Trisomy 20p?

Trisomy 20p is a chromosomal disorder resulting from duplication of all or part of the short arm of chromosome 20. It is mostly characterized by normal growth, mild to moderate intellectual disability, speech delay, poor coordination and evocative facial features.

What does an extra 20 chromosome mean?

An error in cell division, called nondisjunction , results in an egg or sperm cell with an abnormal number of chromosomes. If an egg or sperm cell gains an extra copy of chromosome 20, the embryo will have an extra chromosome 20 in each cell of the body.

What are the symptoms of trisomy 20?

Mosaic trisomy 20 is a rare chromosomal anomaly syndrome with a highly variable phenotype ranging from normal (in the majority of cases) to a mild, subtle phenotype principally characterized by spinal abnormalities (i.e. stenosis, vertebral fusion, and kyphosis), hypotonia, lifelong constipation, sloped shoulders, skin …

Is Ring chromosome 20 syndrome a genetic disorder?

r(20) syndrome is a rare genetic disorder characterized by a ring chromosome 20 replacing a normal chromosome 20. It is diagnosed by means of conventional cytogenetics (karyotyping).

Is Ring chromosome 20 syndrome hereditary?

Ring chromosome 20 syndrome is almost never inherited. A ring chromosome typically occurs as a random event during the formation of reproductive cells (eggs or sperm) or in early embryonic development.

What causes trisomy disorders?

The most common cause of trisomy is a problem in the duplication of chromosomes to create egg and sperm cells. Somewhere along the way, a chromosome duplicates itself twice, creating a full pair. When the egg or sperm cell joins with its counterpart, the extra chromosome is taken along, creating a set of three where where should be two.

What is chromosome 22 ring?

Chromosome 22 Ring is an extremely rare condition caused by having an abnormal chromosome 22 that forms a ring. In this chromosome abnormality, a segment on the short (p) arm and a segment on the long (q) arm of 22 are missing, however, the amount of material lost varies from person to person.

What is ring syndrome?

Ring chromosome 1 syndrome is an autosomal anomaly characterized by variable clinical features, most commonly including significant intrauterine and postnatal growth failure, developmental delay, intellectual disability, microcephaly , and dysmorphic facial features.