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Patau syndrome, also known as trisomy 13 and trisomy D, is a chromosomal abnormality, a syndrome in which a patient has an additional chromosome 13 due to a nondisjunction of chromosomes during meiosis. Some are caused by Robertsonian translocations. The extra chromosome 13 disrupts the normal course of development, causing heart and kidney defects amongst other features characteristic of Patau syndrome. Like all nondisjunction conditions (such as Down syndrome and Edwards syndrome), the risk of this syndrome in the offspring increases with maternal age at pregnancy, with about 31 years being the average. Patau syndrome affects approximately one in 10,000 live births.The following data has been taken from the National Down Syndrome Cytogenetic Register Annual Reports 2008/09. in England and Wales there were 172 diagnoses of Patau’s syndrome (trisomy 13), with 91% of diagnoses made prenatally. There were 111 terminations, 14 stillbirth/ miscarriage/ fetal deaths, 30 outcomes unknown, and 17 live births. Approximately 4% of Patau’s syndrome with unknown outcomes are likely to result in a live birth, therefore the total number of live births is estimated to be 18. 2008/09 data are provisional.
Most cases of Patau's syndrome result from trisomy 13, which means each cell in the body has three copies of chromosome 13 instead of the usual two copies. A small percentage of cases occur when only some of the body's cells have an extra copy, resulting in a mixed population of cells with a differing number of chromosomes; such cases are called mosaic Patau.
Patau syndrome can also occur when part of chromosome 13 becomes attached to another chromosome (translocated) before or at conception. Affected people have two copies of chromosome 13, plus extra material from chromosome 13 attached to another chromosome. With a translocation, the person has a partial trisomy for chromosome 13 and often the physical signs of the syndrome differ from the typical Patau syndrome.
Most cases of Patau syndrome are not inherited, but occur as random events during the formation of reproductive cells (eggs and sperm). An error in cell division called non-disjunction can result in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of the chromosome. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 13 in each of the body's cells. Mosaic Patau syndrome is also not inherited. It occurs as a random error during cell division early in fetal development.
Patau syndrome due to a translocation can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 13 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 13. Although they do not have signs of Patau syndrome, people who carry this type of balanced translocation are at an increased risk of having children with the condition.
Of those embryos that do survive to gestation and subsequent birth, common abnormalites include:
Trisomy 13 was first observed by Erasmus Bartholin in 1657, but the chromosomal nature of the disease was ascertained by Dr. Klaus Patau in 1960. The disease is named in his honor. Patau syndrome was also described in Pacific island tribes. These reports were thought to have been caused by radiation from atomic bomb tests. The tribes were temporarily moved before and during the test by an x amount of distance. They were then put back where they had been taken; all of this occurred before it was known how long, or even if, radiation still lingered on after a nuclear explosion.
Medical management of children with Trisomy 13 is planned on a case-by-case basis and depends on the individual circumstances of the patient. Treatment of Patau syndrome focuses on the particular physical problems with which each child is born. Many infants have difficulty surviving the first few days or weeks due to severe neurological problems or complex heart defects. Surgery may be necessary to repair heart defects or cleft lip and cleft palate. Physical, occupational, and speech therapy will help individuals with Patau syndrome reach their full developmental potential.
Patau Sydrome, also known as Trisomy 13 or Trisomy D is a problem with the chromosomes. People who suffer from it have an extra copy of chromosome 13. This is usually because of a problem that occurred during meiosis, but it can also be the result of Robertsonian translocation, a common rearrangement of chromosomes in humans. The risk of getting a problem during meiosis increases when women have babies later in life. The average age for this syndrome is at 31 years.