Patau Syndrome

Patau syndrome is a hereditary disorder which occurs because of an extra copy of chromosome 13. Usually there are two copies of chromosome 13, but in this case, instead of 2 there are 3 copies.

Patau syndrome is mostly called as Trisomy 13 wherein a part of chromosome 13, or whole, is three times more in each cell of the body in place of 2 times. In few cases, only some percent of the cells may have extra copy of chromosome 13, whereas the other cells may have the normal 2 pair of copies. This additional copy of chromosome 13 causes abnormalities, both physically and intellectually. Its incidence rate is one in 10 to 16000 babies.

Most babies are affected by this chromosomal anomaly not due to hereditary causes, but because of random events that occur during development of egg and sperm in healthy couples. Because of medical problems associated with this syndrome the affected infant usually dies very soon in the 1st few days after his/her birth, or after some weeks. Only five to ten percent of the affected infants survive for more than one year.

It is easy to detect Patau syndrome as its signs and symptoms are very different and unusual. These symptoms can be clearly seen and at times some anatomical changes may occur in the internal parts of the body. Several defects such as small head, injured retina, small eyes, extra finger or toe, a missing eye, cleft or curved palate, unusually shaped ears, etc. may be seen at the time of birth in the affected infant.

Symptoms of Patau syndrome

Some of the common signs and symptoms of Patau syndrome are mentioned below:

• Affected infants may face many problems in consuming food or feeding. Hence, weight gain may not be normal as per the growth.
• The baby may experience breathing problems like apnea and physical defects like additional toe or finger, cleft lip, tiny eyes, less muscle weight, and cleft palate
• Brain or spinal cord and heart problems may be present.
• Most Patau syndrome affected children suffer from congenital heart abnormalities like:
  • In some cases the affected child may suffer from dextrocardia. This is a cardiac state wherein the heart may be situated not on the left side but on the right side of the body.
  • Affected babies may experience other abnormalities like atrial septal defect. In this a hole is present in between the upper chambers of the heart which causes difficulty for the heart to function effectively. The heart is not able to fully pump the oxygen-rich blood to the various parts of the body.
  • A channel in the heart usually shuts up just before birth. However if the child gets affected by Patau syndrome, then an incomplete closure of the channel can cause patent ductus arteriosis.
  • An affected baby may also experience ventricular septal defect. In this abnormality there is a hole between the 2 lower chambers of the heart which stops the heart from pumping the blood effectively.

Some other signs and symptoms are as follows:

• Closed fists
• Skeletal anomalies
• Clenched hands
• Hernia
• Mental retardation
• Defects in scalp, skin anomalies of the scalp
• Slow growth
• Testicle is undescended
• Kidney defects
• Tiny lower jaw
• A solitary crease on the palm
• Babies may also suffer from developmental abnormalities/defects
• In rare cases, scoliosis
• Gastro-esophageal reflux can be seen in the affected baby
• High blood pressure
• The eyes are so close that they may appear to be merged together. The iris of the infant may have a hole, or a cleft, or it may be spilt.
• Seizures

Causes of Patau syndrome

The cause of Patau syndrome is the extra DNA in the chromosome 13, in some or all cells of the body. When an additional chromosome 13 is seen in only few cells, then it is known as a Mosaic mutation. If only a part of the additional chromosome 13 is found in some or all the cells, then it is called as ‘Partial Trisomy 13’.

The extra chromosomal matteris what prevents the proper development of the affected baby and causes the characteristic abnormalities.

Most cases of Patau syndrome are not genetic. It often occurs due to random errors during the formation of the egg or sperm that forms into fetus. Mostly children suffering from this disorder have the additional copy in the all the body’s cells, whereas only few possess the extra chromosome 13 in only some cells of the body. Infants with mosaic Patau syndrome experience milder symptoms in comparison to those babies who have the extra chromosome 13 in all the cells of the body.

Treatment 

Patau syndrome is fatal. Some of the precautions that can be taken to lessen the symptoms are as follows:

• The best way to know/detect the disorder in the unborn baby during pregnancy is through screening method.
• Most infants suffering from Patau syndrome survive only for 1st few weeks. Therefore, treatments are directed at handling the signs and symptoms so as to increase the lifespan of the child.
• Surgeries are opted to correct the abnormalities associated with the disorder, still they are postponed as far as possible because of the high death rate of the baby with Patau syndrome.

 Patau Syndrome Pictures