What does microdeletion mean?
Microdeletions, or submicroscopic deletions, are chromosomal deletions that are too small to be detected by light microscopy using conventional cytogenetic methods. Specialized testing is needed to identify these deletions. Microdeletions are typically 1 to 3 Mb long and involve several contiguous genes.
What disorders are caused by microdeletion?
The classical microdeletion syndromes include, amongst others, Angelman syndrome (15q11. 2-q13), Prader–Willi syndrome (15q11. 2-q13), Williams–Beuren syndrome (7q11. 23), Smith–Magenis (17p11.
When do Microdeletions occur?
A microdeletion is an abnormality that occurs when a piece of a chromosome is missing. In fact, it’s just what it sounds like: micro (tiny); deletion (taken away). You might remember from high school biology that virtually all of our cells contain chromosomes with DNA; we get 23 from each parent for a total of 46.
What are the symptoms of microdeletion syndrome?
1 microdeletion syndrome is a rare chromosome disorder. Symptoms may include seizures, moderate to severe learning problems, speech delays, behavior problems, trouble sleeping, and developmental delays (learn to crawl, sit or walk later than other babies). Children affected by 2q23.
Is microdeletion a disability?
Microdeletion is considered to be one of the prenatal causes of intellectual disability.
Why do Microdeletions happen?
Throughout your life, your cells replicate by dividing — and in the process, your body chops up these DNA strands to make them more manageable to use. But once in a while, a tiny bit of a chromosome is removed during this process, resulting in a microdeletion.
How are Microdeletions inherited?
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.
Is chromosome deletion hereditary?
2 deletion syndrome are not inherited . The deletion occurs most often as a random event during the formation of reproductive cells (eggs and sperm) or in early fetal development. Affected people typically have no history of the disorder in their family, although they can pass the condition to their children.