What is brachydactyly?
Brachydactyly is a shortening of the fingers and toes due to unusually short bones. This is an inherited condition, and in most cases does not present any problems for the person who has it. There are different types of brachydactyly, based on which bones are shortened. This condition can also be a symptom of other genetic disorders.
Unless there is an accompanying disorder that produces symptoms, or the shortened digits impair the use of hands and feet, there is no treatment needed for brachydactyly.
Symptoms of brachydactyly
The signs of brachydactyly are usually present at birth, but it’s possible that shortened limbs become more obvious with growth and development. The main symptom of brachydactyly is fingers, toes, or both that are shorter than normal. Unless you have another condition associated with brachydactyly, you should not feel any pain or have any other symptoms.
The shortened fingers and toes of brachydactyly may cause you to have difficulty with grip. If the brachydactyly is severe in the feet, you may have trouble walking. These symptoms are rare, however, when there is no other condition present.
Causes of brachydactyly
Brachydactyly is an inherited condition, which makes genetics the main cause. If you have shortened fingers or toes, other members of your family most likely also have the condition. It is an autosomal dominant condition, which means you only need one parent with the gene to inherit the condition. It’s thought that two different mutations in a certain gene contribute to brachydactyly.
In some cases, it’s possible that brachydactyly is caused by exposure to medications that the mother takes during pregnancy. It may also be caused by blood flow problems to the hand and feet, especially in developing babies.
It’s possible that your brachydactyly is symptomatic of a genetic syndrome. This is much rarer. If so, you will have other symptoms besides the shortened fingers or toes. Brachydactyly might be caused by Down syndrome or Cushing’s syndrome, for example.
Types of brachydactyly
The different types of brachydactyly are categorized by the bones and digits affected.
Type A brachydactyly is the shortening of the middle phalanges. These are the finger bones that are the second from the end of each digit. Type A is further classified by finger types. These are as follows:
- Type A1: The middle phalanges of all the fingers are shortened.
- Type A2: The index finger and sometimes the little finger are shortened.
- Type A3: Only the little finger is shortened.
Type B brachydactyly affects the ends of the index through little fingers. The last bone on each finger is shortened or completely missing. The nails are also absent. The same occurs in the toes. The thumb bones are always intact but often flattened and/or split.
Type C is rare and affects the index, middle, and little fingers. The middle phalanges, as in type A, are shortened, but the ring finger is often not affected and is the longest finger on the hand.
Type D brachydactyly is considered to be common and affects only the thumbs. The end bones of the thumbs are shortened but all the fingers are normal.
Type E brachydactyly is a rare form if it is not accompanied by another disorder. It is characterized by shortened metacarpals and metatarsals. These are the bones in the hands and feet that are third and fourth from the end of the digits. The result is small hands or feet.
Diagnosis of brachydactyly
A careful examination of the hands and feet by a doctor may be enough to diagnose brachydactyly. X-rays can also be used to see which bones are shortened and to diagnose the type of brachydactyly. In mild cases, an X-ray may be the only way to tell that the condition is present.
To determine if brachydactyly is part of a syndrome, a full skeletal X-ray may be done. This can help determine if other bones in the body are abnormal, which suggests a syndrome. Genetic testing may also be necessary to determine if the syndrome is present.
Treatment for brachydactyly
In a large majority of cases of brachydactyly, no treatment is necessary. If your condition is not a part of another syndrome, you should be healthy and will have no medical concerns related to your hands and feet.
In rare cases, brachydactyly may be severe enough to present problems with functionality. You may have trouble gripping things or walking normally. In these instances, physical therapy can help. Physical therapy can improve the range of motion and improve both strength and functionality of the affected areas.
In extreme and very rare cases, surgery may be used to treat brachydactyly.
Plastic surgery may be used for cosmetic purposes, or in rare cases, to improve functionality. Many who need surgery will have brachydactyly along with another condition. Surgery may include an osteomy, which cuts the bone. This can contribute to “gradual lengthening” of the shortened fingers.
Brachydactyly is typically an inherited condition. If you have a family member with brachydactyly, your risk for also having it is much higher.
If your child is born with Down syndrome, their risk for brachydactyly is higher.
Women are more likely to develop brachydactyly than men. This may be partly because women are more likely to experience the full expression of the trait than men. This makes it more noticeable in them.
Most people with brachydactyly won’t experience any significant complications that hinder their daily lives. In some cases, if the brachydactyly is severe enough, it can limit the functioning of the hand or difficulty walking. Surgery and physical therapy may be used to improve functioning.
Outlook for brachydactyly
Almost all people with brachydactyly live completely normal lives. Some may feel self-conscious about the appearance of their hands or feet, but they are otherwise healthy. If brachydactyly is connected to another syndrome, the outlook varies depending on the individual situation.