The genetic abnormality that is responsible for this disorder is a DNA mutation. This mutation caused an increase in a protein called transforming growth factor beta or TGF-B. the increase in TGF-B causes problems in the connective tissues throughout the body which then causes the body to develop long legs, arms, and fingers as well as heart problems.

The chromosome that the genetic abnormality been mapped to is chromosome 15 when a mutation happens in the FBN1 or fibrillin gene. this weakens the tendons, ligaments, and other connective tissue.

The phenotype of someone who has this disorder is something that is called the MASS phenotype which consist of the M is Mitral value, A is Aorta, S is Skin and S is for Skeletal features. Mitral value is when the flaps of one of the heart values are "floppy" and don't close tightly. The Aorta root diameter may be at the upper limits for the normal body size. but unlike Marfan Syndrome there is no progression to aneurysm. The Skin may show stretch marks not caused by weight gain or loss. Some Skeletal features that may be present is scoliosis which is the the curvature of the spine.

The disorder is diagnosed by the doctors observation or checking complete medical history due t the reason that there is no blood test or skin biopsy that can be done to diagnose this.

Some treatment options that are available for people with this is surgery to get a heart value repair. You could also get a back brace, glasses, and contact lenses.

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. At least 25 percent of Marfan syndrome cases result from a new mutation in the FBN1 gene.