Doctor insights on:
Patau Syndrome (Trisomy 13)
How to know if certain people are more likely to get trisomy number 13 patau syndrome than others?
Ordinary chromosomal traits require a pair of chromosomes to determine the traits. Occasionally, as a mistake in cellular division, there is a tripling of one of the chromosomes. When these occur, they usually cause unpleasant, and sometimes deadly conditions in the inheritor of these traits (e.g. Down's). Many we do not know about as they are ...Read more
I heard that certain people are more likely to get trisomy number 13 patau syndrome than others, why is that?
Child of older mom: Increasing maternal age increases the risk for chromosome disorders, highlighted by trisomy 21 (down syndrome) but applying to rarer trisomies like the trisomy 13 causing patau syndrome (1 in 8000 births or so). Risks for trisomy increase gradually with maternal age, going from <1 in 2000 under 30 to ~ 1 in 50 over age 40, with age 35 arbitrarily set as high risk (~1 in 200). ...Read moreSee 1 more doctor answer
Lifespan: In my clinical experience of 31 years practicing neonatal medicine, i would have to answer your question with a vague response. This is because each affected child does not necessarily have the same degree of affliction. The literature on this tells us that 99.9% die before a year of age. I have not seen one survive longer than two months, and I have seen many. ...Read more
Days/weeks.: Stillbirth (see picture) is very common. Of liveborns, 80% of affected infants die within the first month of life; only 5% survive the first six months. Severe intellectual disability, seizures, and failure to thrive are noticeable in survivors over 1 year of age. No interventions for fetal benefit are ethically justifiable during pregnancy (no cesarean section, no fetal monitoring indicated). ...Read more
Trisomy 13: Patau syndrome is also called trisomy 13. It occurs when a baby has 3 copies of the number 13 chromosome instead of the usual 2 copies. It causes severe physical problems and most babies with trisomy 13 die before birth or within the first year after birth. It usually happens because of an accident which occurs when the egg is fertilized, and occurs more commonly as mothers get older. ...Read moreSee 1 more doctor answer
Unclear: The information you list provides no specific information on which to base an answer. How was the data obtained and why? Does it relate to some specific test, a pregnancy, a genetic counseling session ? Questions should provide basic information on the problem and ask a clear question. The public site is not a chat room and none of your prior submissions are linked. Try again if you wish. ...Read more
Chromosome error: Humans have 23 pairs of chromosomes(c) making up our dna.When the egg or sperm form, the (c) pairs are supposed to split up with 1 (c) of each pair going to the egg or sperm.If the 13 (c) does not split & both go into an egg, fertilization will add a 3rd from dad & a trisomy 13 will begin to form. The imbalanced (c) causes malformations, miscarriage or early death. ...Read moreSee 1 more doctor answer
They don't: Trisomy 13 is a spontaneous new event that occurs when 2 #13 chromosomes in either the egg (sperm) join with the one from the opposing side. The other 22 chromosomes pass only one of each. The fetus ends up with 47 chromosomes, not the normal 46. It is not passed on the genes like eye color or other features. It is an accident of nature. ...Read moreSee 1 more doctor answer
Not to my knowledge: Trisomy is caused by a robertsonian translocation in the karyotype of one of the parents or by a meiotic nondisjunction event of a sperm or egg cell. 88% of time trisomy comes from nondisjunction in the maternal egg and 8% comes from nondisjunction in the paternal sperm. ...Read more
Neither: Any defect like trisomy 13, that involves acquiring an extra chromosome, has nothing to do with dominant or recessive genes. It occurs when usually the egg carries 2 rather than 1 of the 13 chromosomes. Fertilization by a normal sperm with one of every chromosome creates an embryo with three # 13's.If the embryo survives pregnancy it emerges as a trisomy 13 infant with all the problems they have. ...Read more
Not true: Trisomy 13 (3 copies of chromosome 13 in all your cells) is caused by an error in the way one of your two chromosome 13s move when you make an egg or a sperm. It's called nondisjunction. When it happens, it's no one's fault. Marriage between close relatives, like 1st cousins, is common in many places in the world, and trisomy 13 is just as rare there as it is everywhere else. ...Read moreSee 1 more doctor answer
Not really: If you suspect or have a confirmed pregnancy with T13 you have decisions to make. The condition is universally fatal & those who survive pregnancy live only a short time after birth. Delivery at a center that has medical genetics and neonatology can help confirm the diagnosis and allow the most time for you to can have to get acquainted with baby before the end comes. ...Read moreSee 1 more doctor answer
I'm 32, trisomy 13/18 u/s show 1:750, blood test shows 1:396. Doc says normal but offered extra test 4 PC of mind. Should i be concerned about result?
Only reason: Is to take the test for your peace of mind. Always a slight chance. ...Read more
Chromosome defect: This syndrome results when an egg with a pair of chromosome 13 (instead of 1) joins with the male's 13 at conception leading to a distortion of the information in each cell of the body.Multiple birth defects are common and these kids do not live very long. It is not inherited on the genes. ...Read more
Trisomy 13: Patau syndrome is also known as trisomy 13. This is an extra chromosome 13 and leads to intellectual and physical disabilities. Heart defects, brain or spinal cord abnormalities, very small or poorly developed eyes, extra fingers and/or toes, cleft lip with or without a cleft palate, and weak muscle tone. Approximately 5-10% of children live beyond the first year of life. ...Read more
Non-disjunction.: The majority of cases of the lethal patau or trisomy 13 syndrome are caused by nondisjunction (47, +13) related to advanced maternal age. Robertsonian translocations of either parent can increase the risk for that couple, although most affected embryos die in utero. ...Read moreSee 1 more doctor answer
It's not: Patau syndrome arises from a non-disjunction event prevents the 18 chromosome from dividing its pair & sends 2, not one to the egg. At conception the sperm brings along another 18 & there ends up being 3. The presence of the extra 18 causes the developing fetus to misread the genetic instructions and many defects occur. ...Read more
Supportively: Patau is a chromosomal abnormality of trisomy 13. There is no treatment of the cause but the various symptoms can be treated. For example, heart defects can be repaired, polydactyly can be corrected. However, many children live only a short time so often the goal is comfort care. ...Read more