A patient having an extra chromosome 13 means he suffers from the rare Patau syndrome, or Trisomy 13 and Trisomy D. It causes chronic neurological, heart and kidney defects because of the extra copy of chromosome 13 interfering with the normal course of development. The conditions are similar to the Down syndrome and Edwards syndrome associating risk with the increased maternal age at pregnancy. Patau syndrome equally affects people of all ethnic backgrounds and roughly one in 10,000 live births.
Mostly, Patau syndrome results from trisomy 13, which means that three copies of chromosome 13 instead of two copies are present in every cell of the body. It rarely occurs that just a few of the cells in the body have an additional copy, leading to a mixed population of cells having a different number of chromosomes, known by the name of mosaic Patau.
At conception or before that, Patau syndrome might occur when part of chromosome 13 attaches to another chromosome. There are two copies of chromosome 13, plus additional material from chromosome 13 linked to another chromosome, in these individuals.
Patau syndrome occurs as a random event throughout the formation of both the eggs and sperm, and is usually not inherited. Reproductive cells with an atypical number of chromosomes might be a result of an error known as disjunction. Mosaic Patau is not inherited either for in the stage of foetal development a random error during cell division results in Mosaic Patau.
Translocation might result in an inherited Patau syndrome meaning an uninfected individual carries a repositioned genetic material between chromosome 13 and another chromosome. It is called balanced translocation, as there is no additional material from chromosome13. These people do not present any signs of Patau syndrome but may be have infected children.
Newborns with Patau syndrome that survive to gestation and birth share common abnormalities, such as extra fingers or toes, deformed feet, chronic deficiency, facial defects, malformed nose, heart and kidney defects, etc.
At birth, Patau syndrome might be mistaken for Edwards syndrome even though the signs are present and that is why genetic testing should be carried out to confirm diagnosis. Computed tomography or magnetic resonance imaging should be performed to identify any heart, kidney and brain defects. An ECG should also be carried out to diagnose any heart defects associated with Patau syndrome.
Erasmus Bartholin (1657) initially observed Trisomy 13, but Dr Klaus Patau (1960) determined the chromosomal nature of the syndrome and the disease honors his name. Treatment of children with Trisomy 13 follows a case-by-case basis and depends on the patient’s circumstance. A concentration is on particular physical problems when each infant is born. Because of the numerous neurological problems or multiple heart effects several infants hardly survive the first days or weeks. Surgical procedure might necessitate fixture of heart defects and different and combined therapies such as physical and occupational will help infected individuals reach their complete developmental potential.