When Biology Takes a Turn , Birth Defects II

From a condition that turns children into the images of 70 year olds to conditions that affect twin births, there are many swift turns that biology can take that can cause a birth defect. In this article, you will also encounter conditions called Craniopagus Parasiticus and Fibrodysplasia Ossificans Progressiva.

Vestigial Tail

Some children are born with a semi-functional tail known as a vestigial tail, which has its own muscles, nerves, skin and blood vessels. Some believe that a mutation of genes found in infants that cause the disorder to emerge. As a result, some children are unable to discard the body parts on a cellular level that are not needed in their life.

Craniopagus Parasiticus

A child born with craniopagus parasiticus has a condition that causes a parasitic extra head of an unborn twin to develop. In history, there have only been 10 documented cases of this disorder. Only three surviving births have taken place. In one case, the second head could even smile, blink, cry and suckle.

Fetus in Fetu

A child can actually be born with a twin inside of its body. This phenomenon gives the appearance that the child is pregnant. Called fetus in fetu, both twins form from one egg, but somewhere along in the pregnancy, one of the twins becomes absorbed by the other and starts to live off of the remaining twin , like a parasite. Surgery is usually an option to remove the undeveloped twin from the stronger child with no adverse effects to the developed twin.

Fibrodysplasia Ossificans Progressiva

Children that are born with Fibrodysplasia Ossificans Progressiva have a disease that causes bone to grow in parts of the body that are injured. Under normal circumstances, a child will develop a scar when hurt or the skin grows back. However, a child with this disease will grow bone instead. Over time, the increasing amount of bone ion the body can cause other medical issues to emerge. The excess bone starts to fuse joints together. A downside is that the bone cannot be surgically removed because this would mean that more bone would grow over the surgery wounds.


Occurring in one in 8 million births, progeria is a birth defect that causes the extremely advanced aging of a child. They will look well beyond their age , losing their hair and developing wrinkles. The youthful face of a young child is replaced by the facial characteristics of the elderly. The disease causes severe arterial damage, which means victims of the condition usually die by the time they become an adolescent.