People with symbrachydactyly are born with fingers, a full hand, or an arm that didn’t develop normally. Symbrachydactyly affects each person differently.
If your child has this condition, they might have one hand or arm that’s smaller than the other, and they might have webbed fingers or fingers that shorter than normal and not completely formed. In more severe cases, in place of fingers, your child might have digits that look like small stumps or nubbins made up of only skin and other soft tissues. In the most severe cases, their fingers might be missing completely.
Symbrachydactyly vs. Brachydactyly
Symbrachydactyly and brachydactyly are terms that are sometimes used interchangeably, but they don’t always refer to the same condition. Brachydactyly is a more general term that is used when a person has webbed, underdeveloped, or missing fingers or toes. Brachydactyly can affect either your hands or feet and often affects both their hands and feet.
Symbrachydactyly is a more specific term for when the webbing or deformations affect only one of your child’s hands. Either hand can be affected, but the left hand is the most commonly affected.
Types of Symbrachydactyly
Symbrachydactyly will look different for each person that has it. The finger bones are usually not the only affected part — tendons, ligaments, muscles, and nerves can all be affected, too. Symbrachydactyly is usually organized into different types depending on how severely it affects your child’s fingers and which fingers are affected.
Short finger symbrachydactyly. The most common and least severe type is short finger symbrachydactyly. Children born with this type usually have working and normal-looking thumbs, but their other fingers will be shortened and might be webbed or awkward.
Bidactylous symbrachydactyly. People with this type will have two developed digits — their thumbs and little fingers. Other fingers will vary in terms of development and function.
Monodactylous symbrachydactyly. In cases of monodactylous symbrachydactyly, only one digit, the thumb, will be formed and usable.
Adactylous or peromelic symbrachydactyly. This is the most severe form of the condition. People born with this type of symbrachydactyly will be missing all of their fingers, or else they will all be severely stunted and malformed. Some people with this type of symbrachydactyly might also not be able to move their wrists properly.
Symbrachydactyly Causes
Symbrachydactyly is a rare condition and affects only about 1 in 32,000 babies born each year. It is congenital, meaning that people are born with this condition.
In most cases, symbrachydactyly appears as a random mutation without any known cause or other health and development issues. There isn’t any current or strong evidence that suggests symbrachydactyly is a genetic or inherited condition. Your baby’s sex is also not a risk factor because symbrachydactyly affects both male and female infants equally.
In some cases, symbrachydactyly is a symptom of Poland syndrome. People with Poland syndrome have underdeveloped or missing chest muscles along with symbrachydactyly on one side of their body.
Symbrachydactyly Diagnosis
Babies with symbrachydactyly are usually diagnosed at birth during their routine newborn exam. Sometimes symbrachydactyly can be diagnosed earlier if it is seen during a prenatal ultrasound.
Symbrachydactyly can sometimes look similar to a different condition called amniotic band syndrome (ABS). ABS might occur when the inside layer of the amniotic sac tears and pieces of the outside tissue around it get tangled around a part of your baby’s body.
ABS can cause damage to parts of hands and fingers that were developing normally. This is different from symbrachydactyly, which will often affect other inner parts of the hand that aren’t seen as easily, like nerves and muscles, along with bones.
If your baby is born with symptoms of symbrachydactyly, your doctor will likely have x-rays or other imaging tests taken of their hand. These tests help your doctor see how much of their bones and tissues are affected, confirm their diagnosis, and develop the best treatment plan.
Symbrachydactyly Treatment
When treating symbrachydactyly, there are three main goals doctors hope to achieve:
- Improving how well your child can use their hand and fingers
- Making your child's hand and fingers look more normal
- Helping you and your child understand and accept potential limitations
Since symbrachydactyly is unique for each person, treatment plans will vary. Your doctor might recommend different surgical or non-surgical treatment options depending on the type and severity of symbrachydactyly your child has.
Surgery to treat symbrachydactyly can involve several different procedures. Sometimes, surgery can be done to remove finger webbing, loosen knuckle joints and help fingers to move more independently. This can help your child pinch or grasp objects and use their hand more effectively.
Other operations might aim to lengthen your child’s fingers using bones from their toes to help their fingers look more normal. If your child’s fingers are missing completely, toes can also be transplanted from your child’s feet to their hands to give them more functionality.
Non-surgical treatment options include physical and occupational therapies or prosthetics to help your child learn to use their affected hand and fingers more effectively. Therapists will offer support and guidance to your child as they learn and build their self-esteem.
Symbrachydactyly Outcomes
The outcome for children with symbrachydactyly greatly depends on the type and how severely it affects them. Proper treatment for your child's unique condition can be very effective in helping children improve how well their hands and fingers function.
Surgical treatments have been very successful at helping children better move and use their hands and fingers. Some children can see significant improvement after one surgery, but others might need additional surgeries to correct issues and improve function as they grow.
Many children have also learned to adapt and use their hands and fingers more effectively after going through physical therapies and other non-surgical treatments. As your child gets older, prosthetics might help them play sports or perform daily activities.
Even with treatment, children with symbrachydactyly might always have hands and fingers that look and work differently. Long-term management, care, and support are necessary to find solutions to help your child reach their full potential as they grow.