Microdeletion syndromes

Sub-microscopic deletion of a part of a chromosome (1-3 million bp) that are too small to see on standard microscopy.

Sometimes involves loss of a few contagious genes (contagious gene syndromes).

Sometimes involves micro duplications.

They can be detected using specific FISH testing, MLPA or CGH microarray.

 Examples of microdeletion syndromes:

• DiGeorge syndrome or velocardiofacial syndrome  – most common microdeletion syndrome.
• Prader–Willi syndrome.
• Angelman syndrome.
• Williams syndrome.
• Miller–Dieker syndrome.
• Smith–Magenis syndrome.
• Rubinstein–Taybi syndrome.
• Wolf–Hirschhorn syndrome.