How common is duplication syndrome?
Well over 200 individuals have been reported in the medical literature. It has been estimated that approximately 1-2% of unexplained cases of X-linked intellectual disability may be due to MECP2 duplication syndrome.
How common is Microduplication?
1 microduplications occur in about 3 in 10,000 individuals in the general population. Studies suggest that these chromosomal changes are 15 to 20 times more common in people with schizophrenia or tetralogy of Fallot.
What does it mean if you have a duplicated chromosome?
Chromosome duplication: Part of a chromosome in duplicate. A particular kind of mutation involving the production of one or more copies of any piece of DNA, including sometimes a gene or even an entire chromosome. A duplication is the opposite of a deletion.
Is chromosome duplication bad?
Since a very small piece of a chromosome can contain many different genes, the extra genes present in a duplication may cause those genes to not function properly. These “extra instructions” can lead to errors in the development of a baby.
Can duplication syndrome be inherited?
In most cases, MECP2 duplication syndrome is inherited from a mother who carries the duplication but has no symptoms. Rarely, the condition is not inherited. In these cases it may occur randomly during the formation of the egg or sperm, or shortly after the egg and sperm join together.
How many microdeletion syndromes are there?
Theoretically, for every microdeletion syndrome there should be a reciprocal microduplication syndrome. However, there are at present 211 microdeletion syndromes versus only 79 microduplication syndromes reported (Table 1, Suppl.
What happens if you are missing chromosome 1?
1 microdeletion is inherited in an autosomal dominant pattern, which means that missing genetic material from one of the two copies of chromosome 1 in each cell is sufficient to increase the risk of delayed development, intellectual disability, and other signs and symptoms.
What is a Microduplication?
Microduplications, or submicroscopic duplications, are chromosomal duplications that are too small to be detected by light microscopy using conventional cytogenetics methods. Specialized testing is needed to identify these duplications.
What causes double chromosome?
Errors during dividing of other cells (mitosis)
Mitosis causes the number of chromosomes to double to 92, and then split in half back to 46. This process repeats constantly in the cells as the baby grows. Mitosis continues throughout your lifetime.
What are the symptoms of duplication?
What are the signs and symptoms of MECP2 duplication syndrome?
- Hypotonia (low muscle tone), which is usually apparent in infancy.
- Delayed development of milestones.
- Moderate to severe intellectual disability.
- Inability to talk, or limited speech ability that may be lost with age.