Sirenomelia: Mermaid Syndrome

February 28^th is rare disease day. It is estimated that there are 6,000-8,000 rare diseases in the world today. In the United States, a rare disease is defined as: A disease or disorder that affects fewer than 200,000 Americans at any given time.

DEFINITION OF A RARE DISEASE

There are several characteristics that define a rare disease. These are:

Rare diseases are often chronic, progressive, degenerative, and often life-threatening.

Rare diseases are disabling and the quality of life of patients is often compromised by the lack of or loss of autonomy.

There most likely is a high level of pain and suffering for the patient and the family.

There is usually no existing effective cure for the disease.

75% of rare diseases affect children.

30% of rare disease patients die before the 5 years of age.

80% of rare diseases have genetic origins.

Other rare diseases are caused by infections (bacterial or viral), allergies and environmental causes, or are degenerative or spread rapidly.

SIRENOMELIA: AN EXTREMELY RARE DISEASE (Also Known as Mermaid Syndrome)

Sirenomelia is one of the conditions classified as a rare disease. Recently, a young girl that I had been following on one of the medical health channels with this condition died. What is unusual about this story is the child had lived a fairly normal life for 10 years. She didn't die of complications of her disease but, of pneumonia. She was one of only three people in the world known to have survived Sirenomelia beyond infancy.

The condition of Sirenomelia consists of the legs being fused together from the waist down with no genital organs, bladder or large intestine present. Most children born with this condition die shortly after birth.

Sirenomelia is classified as a "lethal birth defect". Other birth defects are always present in sirenomelia with the most common being abnormalities of the kidneys, genitalia and large intestine. It is also associated with abnormal umbilical cord blood vessels. In a normal fetus, there are two umbilical arteries which pump the blood from the fetus to the placenta and one umbilical vein which returns the blood from the placenta to the fetus.

Most babies who have sirenomelia have only one umbilical artery and one umbilical vein. This condition severely impairs the supply of blood to the legs and pelvic organs. Because of this limited blood flow and loss of nutrition to the area, the lower limbs fail to form as separate legs, the kidneys are malformed and the large intestine dead ends in the abdominal cavity. There is no anal opening and the internal and external genitalia are either absent or malformed. This fusion of the legs gives the appearance of a mermaid, giving the term "Mermaid Syndrome" to the condition. Other birth defects that can occur involving the heart, lungs, arms, brain and spine but is not seen in every individual with sirenomelia. It remains a mystery why a single umbilical artery could cause these changes to occur.

All cases of this extremely rare disease have occurred as isolated cases with no known genetic cause. Sirenomelia has been reported in a variety of ethnic groups around the world and is more common in twin pregnancies and children born to mothers with diabetes mellitus. Sirenomelia is estimated to occur once approximately 600,000 births.

SOURCE: www.sirenomelia.org