What is Trisomy 13?
Trisomy 13 is a chromosomal condition associated with severe intellectual disability and physical abnormalities in many parts of the body. Babies with trisomy 13 often have heart defects, brain or spinal cord abnormalities, very small or poorly developed eyes (microphthalmia), extra fingers or toes, an opening in the lip (a cleft lip) with or without an opening in the roof of the mouth (a cleft palate), and weak muscle tone (hypotonia). Due to the presence of several life-threatening medical problems, many infants with trisomy 13 die within their first days or weeks of life. Only five percent to 10 percent of children with this condition live past their first year.
Babies with trisomy 13 have an extra copy of chromosome 13. Humans typically have 46 chromosomes (23 pairs) in every cell in their body. Humans generally have two copies of every chromosome, including chromosome 13. Chromosomes are made up of genes. Duplicating or deleting genes can cause health problems. People with trisomy 13 have three copies of chromosome 13, and have an extra set of all the genes located on this specific chromosome. Having a whole extra chromosome means there are a lot of genes with the wrong dosage (three copies instead of two copies). The extra genetic material leads to the serious health problems seen in Trisomy 13.
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Are there other names for Trisomy 13?
Trisomy 13 can also be called Patau syndrome or Bartholin-Patau syndrome.
How common is Trisomy 13?
Around 1 in every 10,000 to 1 in 12,000 babies born has trisomy 13. Trisomy 13 is considered a rare condition. However, it occurs more often to babies born to older women, as compared to babies born to younger women. In other words, trisomy 13 is related to maternal age. Trisomy 13 is seen in all populations and is not related to ethnicity.
- Am J Med Genet A. 2016 Apr;170(4):825-37. doi: 10.1002/ajmg.a.37495. Epub 2015 Dec 10.Survival of children with trisomy 13 and trisomy 18: A multi-state population-based study.Meyer RE1, Liu G2, Gilboa SM3, Ethen MK4, Aylsworth AS5, Powell CM5, Flood TJ6, Mai CT3, Wang Y7, Canfield MA4; National Birth Defects Prevention Network.
Are there any other diseases that look a lot like Trisomy 13?
Trisomy 18 may sometimes look like trisomy 13.
- Trisomy 18 is when a person has 3 copies of chromosome 18
- Common symptoms are small head size (microcephaly), small body size, difficulty with feeding, respiratory problems, kidney/ heart/ brain abnormalities
What is pseudotrisomy 13 syndrome?
Pseudotrisomy 13 syndrome is also called holoprosencephaly-polydactyly syndrome. Babies with pseudotrisomy 13 syndrome often have holoprosencephaly which means that their brains have not developed properly. The brain is supposed to divide into two halves, but this distinction does not completely finish in people with holoprosencephaly. People with polydactyly have more than 10 fingers or toes.