MASS Phenotype is a connective tissue disorder that is similar to Marfan syndrome that involves the Mitral valve, Aorta, Skin, Skeletal features similar to Marfan syndrome but does not involve lens dislocation.
What is MASS Phenotype?
Who is at risk?
What is the treatment for MASS Phenotype?
What is MASS Phenotype?
MASS Phenotype is a related disorder that does not involve the eyes, but several other systems similar to Marfan syndrome.
Mitral valve prolapse (MVP) is when the mitral valve of the heart closes properly, but then flops backward allowing leakage of blood into the chamber from which it came instead of moving forward (regurgitation)
Aortic root diameter may be at the upper limits of normal for body size, but there is no progression to aneurysm or predisposition to dissection.
Skin stretch marks unrelated to weight gain (striae).
Skeletal features of Marfan syndrome (including scoliosis, chest wall deformities, and joint hypermobility).
Who is at risk?
MASS Phenotype can be inherited within families and has been shown to result from mutations in the FBN1 gene. It is autosomal dominant, which means that someone with MASS phenotype has a 50/50 chance of passing the gene along to each child.
What is the treatment for MASS Phenotype?Some of the key points of treating MASS Phenotype are listed below. Always talk to your doctor about your specific needs.
Like Marfan syndrome, MASS Phenotype affects different people in different ways. It is important for a person to treat their specific symptoms, regardless of the actual diagnosis.
Treatment of Mitral Valve Prolapse (MVP)
Most people without major symptoms of MVP do not require medical treatment for this condition. It is recommended that the ascending aorta and mitral valve be monitored by echocardiography for enlargement and function yearly and if no progression occurs follow-up can be done every few years.
In the past, people with MVP were usually given antibiotic prophylaxis for routine dental procedures or minor surgery that could introduce bacteria into the bloodstream. However, the American Heart Association revised their guidelines, easing this recommendation. Bacterial infections of the heart can lead to serious complications for people with MVP. Speak to your doctor about whether or not antibiotic prophylaxis is necessary based on your specific circumstances.
Medications called beta-blockers -- such as atenolol (Tenormin), metoprolol (Lopressor), and propranolol (Inderal) -- are used to treat more severe symptoms of MVP. Calcium channel blockers, such as verapamil (Calan) and diltiazem (Cardizem), are useful in those who cannot tolerate beta-blockers, for example those with asthma.
People with serious symptoms may require surgery to replace the mitral valve.
Treatment of the Aorta
The aortic root diameter in people with MASS Phenotype may be at the upper limits of normal for body size, but there is no progression to aneurysm or predisposition to dissection. However, it is recommended that the ascending aorta be monitored by echocardiography for enlargement yearly and if no progression occurs follow-up can be done every few years.
Treatment of Skeletal Conditions
Many of the skeletal features that are similar to Marfan syndrome do not require treatment for most individuals.
Scoliosis is often more severe if it is related to a connective tissue disorder than in people who have scoliosis from an unknown cause.
Bracing is sometimes used in people with curves in the 20-40 degree range who have a reasonable side profile and whose skeletal growth is not yet complete.Surgery is an option when the curve is 40-50 degrees or greater, the side profile is abnormal, and there is back pain due to degenerative changes resulting from the scoliosis. Children need to be monitored carefully during the time they are growing. Adults who have a curved spine must also be monitored because, even between the ages of 15 and 75, there is a risk that the curve will progress.
Annual spinal exams are recommended if there is a significant curvature or pain.
Visit the National Scoliosis Foundation (http://www.scoliosis.org/) for more information on non-Marfan management of scoliosis
Chest Wall Deformities
Surgical repair of chest wall deformities (pectus excavatum) may be necessary when the cardiologist feels that the pectus is interfering with how the heart works. This happens in a minority of cases. The preferred age for the surgical repair of pectus excavatum is 11 to 13 years of age-- when there is just a bit of growth remaining.
Treatment of the Skin
Stretch marks require no medical treatment.