Related Disorders

Quick Links

• Introduction
• Loeys-Dietz syndrome
• Ehlers-Danlos syndrome
• Familial Thoracic Aortic Aneurysm
• Mass Phenotype
• Familial Ectopia Lentis
• Beals syndrome/ Congenital Contractural Arachnodactyly (CCA)
• Other Conditions


An individual may only have one or more of the characteristics of Marfan syndrome but not enough features to meet the diagnostic criteria for Marfan syndrome. There are connective tissue and metabolic disorders which are very similar to Marfan syndrome and some people may have these conditions. A doctor may consider several conditions if there is a differential diagnosis before determining an actual diagnosis.

Whatever the diagnosis, it is important to follow the recommended treatments for each medical problem that has been diagnosed.  Other family members who may be at risk should also be evaluated if the condition is hereditary. 

In this section we have outlined several conditions related to Marfan syndrome and provided links to any conditions which have their own websites for more complete information.

Loeys-Dietz syndrome

For information about Loeys-Dietz syndrome visit the Loeys-Dietz  Syndrome Foundation website at or the Canadian partner website at

Ehlers-Danlos syndrome

For information about Ehlers-Danlos syndrome, visit the Ehlers-Danlos National Foundation website at

Familial Thoracic Aortic Aneurysms

Familial thoracic aortic aneurysm (FAA) which is also referred to as familial aortic dissection, is an autosomal dominant disorder of large arteries in the absence of other syndromes such as Marfan syndrome.  Studies show that there is a higher rate of aortic aneurysm or dissection among people who have relatives who have experienced this condition, which suggests a genetic link.

In FAA a degenerative breakdown of collagen, elastin, and smooth muscle caused by aging contribute to weakening of the wall of the artery. In the aorta, this can result in the formation of an aneurysm. There is also increased risk of aortic dissection.

Mass Phenotype

MASS Phenotype is a connective tissue disorder that is similar to Marfan syndrome in that it involves the Mitral Valve, Aorta, Skin, and Skeletal features of Marfan syndrome but it doesn’t involve lens dislocation.

This condition 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 of their children.

Familial Ectopia Lentis

Ectopia Lentis is characterized by lens dislocation and the skeletal features of Marfan syndrome.  Familial Ectopia Lentis can only be differentiated from “emerging” Marfan syndrome with ongoing clinical follow up including frequent echocardiograms.

Beals syndrome/Congenital Contractural Arachnodactyly (CCA)

Beals syndrome or Congenital Contractural Arachnodactyly (CCA) is a genetic condition which is similar to Marfan syndrome but also very different. Also Beals syndrome is caused by a mutation on the FBN2 gene rather than FBN1.

Beals syndrome can cause the permanent fixation of certain joints (eg. Fingers, elbows, knees, toes & hips) in a flexed position (contractures), long and slender fingers and toes (arachnodactyly) and abnormally shaped ears. People with Beal syndrome have many of the skeletal problems and aortic enlargement that affect people with Marfan syndrome and the treatment of these issues is the same. However the eyes are not affected in Beal syndrome.

Other Conditions

Marfan Habitus (Marfan Skeletal Features)

Some people have the skeletal features of Marfan syndrome but do not have the aortic and eye problems associated with the condition. If you have any of the major skeletal features of Marfan syndrome you should have a thorough evaluation including an echocardiogram and eye exam by an ophthalmologist. Cardiac follow-up with an echocardiogram every few years is recommended.

To view the common skeletal features of Marfan syndrome click here.

Bicuspid Aortic Valve

For information on Bicuspid Aortic Valve, visit the Bicuspid Aortic Foundation at

Stickler Syndrome

For information about Stickler Syndrome, visit


Homocystinuria is an inherited metabolic disorder in which the body is unable to process certain building blocks of proteins (amino acids) properly. The most common form of the condition is caused by the lack of an enzyme called cystathionine beta-synthase.  This form of homocystinuria is characterized by dislocation of the lens in the eye, an increased risk of abnormal blood clots, and skeletal abnormalities. Problems with development and learning are also evident in some cases.

Less common forms of homocystinuria are caused by a lack of other enzymes involved in processing amino acids. These disorders can cause mental retardation, seizures, problems with movement, and a blood disorder called megaloblastic anemia.

Homocystinuria can be diagnosed by urine and/or blood tests, and should be done on any individual with lens dislocation. Symptoms include nearsightedness, dislocated lens of the eye (ectopia lentis) , tendency to develop blood clots (thrombosis), failure to thrive in newborns and/or developmental delays and a tall stature with long thin limbs and fingers, chest deformities, scoliosis.

Weill-Marchesani Syndrome

Weill-Marchesani syndrome (WMS) is a connective tissue disorder characterized by abnormalities of the lens of the eye, proportionate short stature, brachydactyly (shortness of the fingers and toes), and joint stiffness. The ocular problems, typically recognized in childhood, include microspherophakia (small spherical lens), myopia secondary to the abnormal shape of the lens, ectopia lentis (abnormal position of the lens), and glaucoma, which can lead to blindness. Height of adult males is 142-169 cm; height of adult females is 130-157 cm. Autosomal recessive and autosomal dominant WMS cannot be distinguished by clinical findings alone.

Symptoms include eye anomalies including microspherophakia and ectopia lentis, short stature, brachydactyly, joint stiffness  and heart defects. (occasional)


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