What is Cyclopia?
Cyclopia is an extremely rare variant of holoprosencephaly, a congenital disorder, which is characterized by failure of the eyes to be divided into two orbits equally at the time of birth. This means that children with Cyclopia are born with only one eye which is located at the center of the forehead. This is the most severe form of holoprosencephaly.[1,2]
The rarity of this condition can be analyzed by its incidence rate which is about 1 in 100,000 births. Another feature of Cyclopia is the absence of the nose. In majority of the cases females with an embryo that has Cyclopia have still births or spontaneous abortions. Cleft palate and tooth abnormalities along with hormonal imbalances and genital abnormalities are some additional features that are seen in babies with Cyclopia.[1,2]
What Causes Cyclopia?
What exactly causes Cyclopia still remains unknown but there are several risk factors for this condition. These include genetics, gestational diabetes, infections while pregnant, overexposure to ultraviolet light during pregnancy, alcohol and recreational drug use during pregnancy.
The National Institute for Rare Disorders states that chromosomal abnormalities are an important factor in the development of holoprosencephaly of which Cyclopia is a variant of. It is trisomy 13, meaning the fetus has three copies of chromosome 13, which is responsible for holoprosencephaly and Cyclopia.
How Is Cyclopia Diagnosed?
Cyclopia develops within the first 18 to 28 days of pregnancy. The features of Cyclopia can be seen with a regular ultrasound of the fetus during the development stage itself. Additionally, imaging in the form of MRI scans can also be used to make a diagnosis of Cyclopia.
What Is The Life Expectancy For A Child With Cyclopia?
The prognosis of a child with Cyclopia is extremely poor. In fact, majority of the cases of Cyclopia are either stillbirths or the female has a spontaneous abortion. At maximum, infants with Cyclopia survive for a maximum of a few hours. There is no cure or treatment for Cyclopia. Treatment only focuses on providing life support and addressing other symptoms.
In summary, Cyclopia is the rarest and the most extreme form of holoprosencephaly. It is seen in 1 out of 100,000 births. Trisomy 13 is believed to be the cause behind development of holoprosencephaly. Infants with Cyclopia will have characteristic features of a single eye in the center and absence of the nose along with additional genital and tooth abnormalities.[1,2]
Cyclopia develops during the first trimester of pregnancy, within the first month. Most cases of Cyclopia end up with either spontaneous abortion or still births. The survival rates of infants with Cyclopia are very low of just a few hours. The condition is so rare that even parents who carry this hereditary trait very rarely give birth to an infant with Cyclopia.[1,2]