What Is Phocomelia?

Medically Reviewed by Amita Shroff, MD on May 20, 2023
Written by WebMD Editorial Contributors
3 min read

Phocomelia is a rare condition that affects babies at birth. This condition causes the upper or lower limbs of the child to be underdeveloped or missing. Phocomelia can affect one or multiple limbs. This condition can be caused by a genetic syndrome or from exposure to a specific drug during pregnancy.

Phocomelia cannot be reversed, but there are ways to help people manage the condition. 

Phocomelia is a rare birth defect. It goes by different names including pseudo-thalidomide syndrome and Roberts SC-phocomelia syndrome. This rare condition shortens bones and causes the limbs and appendages to be compressed or to not develop at all. In some cases, phocomelia fuses the fingers as well. 

This birth defect has two main causes. Phocomelia can be genetically caused by families with a recessive autosomal trait. But, it can also be caused by taking a drug during pregnancy called thalidomide. 

The most well-known cause of phocomelia is the use of a drug called thalidomide during pregnancy. Thalidomide was once marketed as a safe drug for pregnancy. It was used for treating anxiety and morning sickness. 

Thalidomide supposedly cured depression, gastritis, and insomnia. Phocomelia was found to be a side effect of taking the drug. In some cases, this birth defect caused death at birth. In the 1960s, thalidomide was removed from the market for pregnant women.

‌Thalidomide was largely used in countries around the world, linking to a spike in cases of phocomelia. Though there was a surge in cases, the condition still remained extremely rare, relatively speaking.‌

Phocomelia can also be hereditary. The National Organization for Rare Disorders (NORD) states an "irregular number of chromosomes" may be the cause. With an uneven number of chromosomes, defects are formed in the body. This is linked to shortened or missing limbs.

No one is affected in quite the same way, but there are similarities to this condition.

Phocomelia causes arms and legs to be shorter or missing altogether. The rare birth defect affects the bones, skin, appendages, and even internal organs. In some cases, hands or fingers may be attached to the shoulder. Toes may be attached to ankles or feet to the hips. 

In most cases of phocomelia, the limbs are fused together and appear like flippers, which is where the condition got its name. "Phoco" means seal" and "melia" means limbs. Only in extremely rare cases are there malformities of the face or cranium.  

While phocomelia is a birth defect that causes shortened or missing limbs, there may be other symptoms. They include: 

  • Vomiting
  • Migraines
  • Increased pressure within the skull due to excess cerebrospinal fluid
  • Shorter neck length
  • Mental deficiencies
  • Malformation of the uterus, urethra, kidney, or heart
  • Problems with blood clotting‌

‌These symptoms can be treated with surgery and medications. If you or someone with this condition are experiencing these symptoms, you can talk to your doctor about options to address them.

Phocomelia can have serious complications early on, posing a high stillbirth rate for babies. They will require further medical treatment after birth as well. Getting around and doing daily activities may be a challenge. However, the advancement of prosthetic technology and a health care team can help them build more mobility.  

Most of the complications happen at birth or before. Once the baby is born, there will be treatment and management options available. ‌

Phocomelia is a condition that cannot be cured. It can only be managed. Prosthetics can be built to replace missing limbs. Another way to manage this condition is through physical, occupational, and speech therapy. 

If there are facial or cranial deformities associated with phocomelia, surgery may be required to improve quality of life. 

Today, thanks to medical and technological advances, there are prosthetic options available for children at six months. Starting treatment early can help the child adjust to this way of life.

Phocomelia is a very rare birth defect that poses challenges, but through modern technology the focus is on managing the condition.