Velocardiofacial Syndrome and Marfan Syndrome
A patient with a deletion of 22q11.2
Microdeletions – result in a very small piece of chromosome to be missing. Special tests are needed to detect these. Many of these entities are variable (i.e. every person’s are a bit different).
Presents in many ways:
10-25% familial origin, but almost always (75%) from mother. This may be because women with this condition can more often form stable relationships resulting in children.
Microdeletion is on chromosome 22, a gene rich chromosome. Is this deletion of one gene or many genes? Not known as of yet.
- In newborn period – digeorge syndrome, immune problems, heart problems.
- In adolescent period – speech problems, learning disabilities, social problems, hyper-nasal speech.
- In adult period – behavioral problems, psychological problems.
Þ aortic valve incompetence Þ anyeurysm
no patients will have all features thus Marfan’s is pleiotropic and highly variable
- skeletal: long, thin fingers, scoliosis, chest wall deformities
- ocular: retinal detachment, bilateral lens delocation
- cardiovascular: dilation of aortic root, aortic regurgitation
- aortic dilation
Þ decreased fibrillin (a component of connective tissue)
gene for fibrillin FBN1
- autosomal dominant
- chromosome 15q