Tall, slender people with long limbs are sometimes suffering from a genetic condition called Beals syndrome. The mutations that cause the condition, in a gene called FBN2, affect a protein called fibrillin-2 which is used to build musculature. This results in elongated and permanently flexed fingers and toes, crumpled-looking or creased ears, scoliosis, underdeveloped muscles, and a protruding chest. In many cases, patients also have heart problems. Clubfoot is also common with Beals syndrome. The effects on the fingers and toes are reflected in another name for the condition, congenital contractural arachnodactyly, meaning spider-like digits that don’t straighten all the way. Beals syndrome is very rare, effecting only about one in 10,000 people.
Beals syndrome is very easy to diagnose because patients only need to inherit the defective gene from one parent. That means there are no asymptomatic carriers—most people with Beals syndrome have at least one parent with Beals syndrome, in whom some of the symptoms will be visible. Sometimes it appears in families with no previous history of this condition.
In such cases, doctors do an investigation looking into how long the fingers have exhibited signs of the disorder, what other symptoms the patient has exhibited, if there’s anything else unusual, and if there’s any family history of early death or of hereditary ailments such as Marfan syndrome. Marfan is a musculoskeletal condition with similar symptoms to Beals, but involving a different muscle-related gene. Testing is also done, looking for reduced bone mass, poor muscle development, and heart abnormalities characteristic of the condition.
Treatment of Beals syndrome involves physical therapy and careful monitoring to make sure the heart is functioning correctly. Beals syndrome can in some patients cause the valve on the left side of the heart, called the mitral valve, to become damaged and deformed, and even to collapse. In addition, patients are sometimes given braces to help them with mobility and stability.