Sirenomelia is when a baby is born with their legs fused together causing it to look like a mermaid tail

This condition is found in approximately every 100,000 births in the US, The baby then usually dies within two or three days due to urinary and kidney abnormalities.

Some sources in the medical literature classify sirenomelia as the most severe form of caudal regression syndrome, a complex developmental disorder.

sirenomelia is usually incompatible with life; death occurs in the perinatal period.

Progeria is an extremely rare genetic disease wherein symptoms resembling aspects of aging are manifested at a very early.

The word progeria comes from the Greek words "Pro" Meaning "Before" and "Geras" Meaning "old age."

Those born with Progeria typically live to their mid teens and early twenties.

The earliest symptoms of Progeria may include failure to thrive and a localized scleroderma-like skin condition.

Symptoms include skin changes, abnormal growth, and loss of hair.

No treatments have been proven effective.

Growth hormone treatment and the use of morpholinos have also been attempted in order to reduce Progerin production.

It is a form of holoprosenephaly and is a congenital disorder characterized by the failure of the embryonic prosencephalon to properly divide the orbits of the eye into two cavities.

Typically the face is either missing replaced with a non functioning nose in the form of proboscis.

Although cyclopia is rare, several cyclopic human babies are preserved in medical museums.

Genetic problems or toxings can cause problems in the embryonic forebrain-dividing process