The MASS phenotype is a hereditary disorder of connective tissue that shares features with Marfan Syndrome.


Inheritance: autosomal dominant


Gene affected: FBN1


Clinical findings ("MASS"):

(M) mitral valve prolapse

(A) aortic root dilation

(S) striae (skin stretch marks unrelated to pregnancy or weight gain)

(S) skeletal changes similar to Marfan syndrome (scoliosis, joint hypermobility, chest wall deformities such as pectus)


Additional findings may include:

(1) myopia


Features absent:

(1) ectopia lentis and other ocular changes of Marfan syndrome

(2) aortic aneurysm

(3) aortic dissection


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