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The month of March is Trisomy Awareness Month. This month was founded by the Support Organization for Trisomy 18, 13 & Related Disorders as a way to raise awareness about less common trisomy disorders, such as Trisomy 18 (Edward’s Syndrome) and Trisomy 13 (Patau Syndrome).
The most commonly understood and well-known trisomy is Trisomy 21 – also known as Down Syndrome – but even few nurses may be unaware of other trisomies like Trisomy 18 and Trisomy 13, as they are far less common, and children who are born with these diseases tend to have short lifespans and poor outcomes.
In this article, we’ll take a deeper look at trisomies, and give you some information about the common forms of these diseases, so that you can spread the word and help build awareness about these uncommon genetic disorders.
What Is A Trisomy?
Trisomy is a form of aneuploidy – a condition in which an abnormal amount of chromosomes are present. In trisomy, there are 3 instances of a particular chromosome – the chromosome affected by the trisomy is how each form of trisomy gets its name.
For example, if there are three copies of chromosome 21, the affected individual would have Trisomy 21, also known as Down Syndrome.
Typically, trisomy occurs when a chromosome fails to separate properly at the time of cell division. When this happens, the sperm or egg may end up with multiple duplicate copies of one chromosome, leading to trisomy or another form of aneuploidy.
Trisomies can occur to any chromosome – but typically, most trisomies lead to miscarriage or stillbirth, and the child afflicted with trisomy is unable to survive outside of the womb.
However, there are some exceptions, which we’ll look at below.
What Are The Most Common Forms Of Trisomy?
Trisomy 21 is by far the most common form of trisomy. Commonly known as Down Syndrome, this form of trisomy can have significant effects on the health of an afflicted person, but individuals afflicted by this syndrome can survive outside of the womb ably, and go on to live full lives, despite cognitive and physical disabilities.
Trisomy 21 occurs in approximately 1 out of 1000 live births each year, and the prognosis for individuals with Trisomy 21 is quite good, with median life expectancy at 50-60 years in the developed world.
Trisomy 18 is much less common than Trisomy 21, and is also known as Edward’s Syndrome. It is caused by a triplication of chromosome 18. It occurs in approximately 1 in 5,000 live births.
Edward’s Syndrome causes a number of health effects, such as microcephaly, heart defects, breathing difficulties, and condition such as esophageal atresia.
Very few children born with Edward’s Syndrome survive. Miscarriages and stillbirths are common, and nearly half of all children who are born with Trisomy 18 do not make it past their first year of life, and the median lifespan of children affected by this disease is 5-15 days.
However, one percent of children with Trisomy 18 make it to the age of 10, and a retrospective Canadian study of children with Trisomy 18 showed a ten-year survival rate of 9.8%
Trisomy 13 is very uncommon compared to Trisomy 18 and Trisomy 21. Known as Patau Syndrome, Trisomy 13 occurs in somewhere between 1 in 10,000 and 1 in 21,700 live births.
Unlike other syndromes, Trisomy 13 is rarely inherited – it occurs as a random event during the formation of reproductive cells, through an error in cell division known as “non-disjunction”.
Defects such as cleft palates, microcephaly, polydactyly, deformed organs, and heart defects are common among children with Trisomy 13. More than 80% of children with Trisomy 13 die within their first year of life.
However, the prognosis is much better for children who make it past a year – a Canadian study showed that, though median survival time was 12.5 days, the one-year survival rate for children afflicted with Patau Syndrome was 19.8%, and the 10-year survival rate was 12.9%.
What Can Be Done To Help?
The unfortunate fact about trisomy, like so many other genetic disorders, is that there is no cure. However, with proper awareness, knowledge about treatment and support, and knowledge about trisomy, it may be possible to increase the quality-of-life of children born with these diseases and help them live happy lives for as long as they can.
If you are interested in helping to spread the knowledge of lesser known trisomy disorders like Edward’s Syndrome and Patau Syndrome, visit SOFT – The Support Organization For Trisomy 18, 13, and Related Disorders, and learn how you can help.
The organization has plentiful resources for parents who are curious about the disorders, and for nurses and medical professionals who may have to treat children with these rare genetic disorders.
So do what you can to spread awareness of these disorders, and in time, we may find a cure – or a better way to ensure that children with rare genetic disorders such as Trisomy 13 and Trisomy 18 may live for as long as possible, with the best possible quality of life.
