Edwards syndrome is a relatively common congenital syndrome. It occurs in about one out of 5,000-6,000 births and it is associated with severe affection of the whole organism.
The syndrome is caused by a chromosomal aberration. Normally, human cells contain 23 pairs of chromosomes, the cells of patients with Edward's syndrome have three chromosomes number 18 (so-called trisomy of the 18th chromosome) instead of normal one pair. The presence of redundant genetic information causes serious malformations of many tissues and organs. The risk of Edwards syndrome in a child increases with higher maternal age.
Affected infants have a small head, small mouth and lower jaw and cleft defects of the face. Their birth weight is lower than in healthy newborns, their eyes are located far from each other. There are also common deformation of limbs – skin folds between fingers and finger adhesions, bone deformities, contractures of muscles and tendons, etc. Shortened tendons and muscles of the fingers in the upper extremities cause tightly clenched fists and fingers overlaps. Serious are congenital heart defects, which are often related to children's deaths. Abnormalities of the respiratory and digestive system lead to disorders in swallowing and breathing. Male infants usually suffer from undescended testicles. Intellect is significantly disturbed and the individuals suffer from severe mental retardation.
The diagnosis can be determined from the findings of the above symptoms. It is also easy to take a sample of venous blood and examine the genetic information in white blood cells, where we confirm the presence of a redundant 18th chromosome.
Much more important is the fact that the diagnosis can be confirmed even by prenatal screening. It is based on the ultrasound of the fetus and concentration of certain compounds in the mother's blood. When these findings inform us about a high chance of Edwards syndrome, it is necessary to perform amniocentesis, i.e. to take a sample of amniotic fluid containing fetal cells and examine their chromosomes. It is also possible to take a sample of chorionic villi from the placenta and examine them. When the examination proves presence of the 18th supernumerary chromosome, the diagnosis is also confirmed.
Prevention and treatment
There is no treatment of the syndrome. However, if the syndrome is detected in time, in the fetus still in the womb, it is in many countries an indication for abortion. Even when the abortion is not performed, spontaneous stillbirths occur frequently in fetuses with Edwards syndrome and when born alive, these children usually do not live to the end of the first year of their life.