MASS syndrome
| MASS syndrome | |
|---|---|
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| This condition is inherited in an autosomal dominant manner | |
| Specialty | Medical genetics  |
MASS syndrome is a medical disorder similar to Marfan syndrome. MASS stands for: Mitral valve prolapse, Aortic root diameter at upper limits of normal for body size, Stretch marks of the skin, and Skeletal conditions similar to Marfan syndrome. MASS Phenotype is a connective tissue disorder that is similar to Marfan syndrome. It is caused by a similar mutation in the gene called fibrillin-1 that tells the body how to make an important protein found in connective tissue. This mutation is an autosomal dominant[1] mutation in the FBN1 gene that codes for the extracellular matrix protein fibrillin-1;[2] defects in the fibrillin-1 protein cause malfunctioning microfibrils[3] that result in improper stretching[3] of ligaments, blood vessels, and skin.
Someone with MASS phenotype has a 50 percent chance of passing the gene along to each child.
People with features of MASS Phenotype need to see a doctor who knows about connective tissue disorders for an accurate diagnosis; often this will be a medical geneticist. It is very important that people with MASS Phenotype get an early and correct diagnosis so they can get the right treatment. Treatment options for MASS phenotype are largely determined on a case-by-case basis and generally address the symptoms as opposed to the actual disorder;[4] furthermore, due to the similarities between these two disorders, individuals with MASS phenotype follow the same treatment plans as those with Marfan syndrome.[5]
MASS stands for the Mitral valve, myopia, Aorta, Skin and Skeletal features of the disorder. MASS Phenotype affects different people in different ways.
In MASS Phenotype:
Mitral valve prolapse may be present. This is when the flaps of one of the heart’s valves (the mitral valve, which regulates blood flow on the left side of the heart) are “floppy” and don’t close tightly. Aortic root diameter may be at the upper limits of normal for body size, but unlike Marfan syndrome there is not progression to aneurysm or predisposition to dissection. Skin may show stretch marks unrelated to weight gain or loss (striae). Skeletal features, including curvature of the spine (scoliosis), chest wall deformities, and joint hypermobility, may be present. People with MASS Phenotype do not have lens dislocation but have myopia, also known as nearsightedness.
MASS syndrome and Marfan syndrome are overlapping connective tissue disorders. Both can be caused by mutations in the gene encoding a protein called fibrillin. These conditions share many of the same signs and symptoms including long limbs and fingers, chest wall abnormalities (indented chest bone or protruding chest bone), flat feet, scoliosis, mitral valve prolapse, loose or hypextensible joints, highly arched roof of the mouth, and mild dilatation of the aortic root.
Individuals with MASS syndrome do not have progressive aortic enlargement or lens dislocation, while people with Marfan syndrome do. Skin involvement in MASS syndrome is typically limited to stretch marks (striae distensae). Also, the skeletal symptoms of MASS syndrome are generally mild.
References
- ^ Dietz, Harry C.; Cutting, Carry R.; Pyeritz, Reed E.; Maslen, Cheryl L.; Sakai, Lynn Y.; Corson, Glen M.; Puffenberger, Erik G.; Hamosh, Ada; Nanthakumar, Elizabeth J. (1991-07-25). "Marfan syndrome caused by a recurrent de novo missense mutation in the fibrillin gene". Nature. 352 (6333): 352337a0. doi:10.1038/352337a0.
- ^ Jacobs, Amanda M.; Toudjarska, Ivanka; Racine, Andrew. "A recurring FBN1 gene mutation in neonatal Marfan syndrome". Archives of Pediatrics & Adolescent Medicine. 156(11): 1081-1085. doi:10.1001/archpedi.156.11.1081.
- ^ a b "FBN1 gene". Genetics Home Reference. NIH. Retrieved 8 November 2017.
- ^ Anon. MASS syndrome. Genetic and Rare Diseases Information Center [Internet]. Available from: https://rarediseases.info.nih.gov/diseases/8489/mass-syndrome
- ^ Pyeritz, Reed E.; for the Professional Practice and Guidelines Committee, Acmg (January 2012). "Evaluation of the adolescent or adult with some features of Marfan syndrome". Genetics in Medicine. 14 (1): 171–177. doi:10.1038/gim.2011.48. ISSN 1098-3600.