What is Trisomy?

Human DNA typically consists of 23 pairs of chromosomes. Trisomy 13 (also known as Patau syndrome) is a genetic condition where the child develops with three copies of the 13th chromosome rather than the usual two copies. About 1 in 18,000 live births are affected by trisomy 13 [1][2]. Trisomy 18 (also known as Edwards syndrome) is a genetic condition where a child develops with three copies of the 18th chromosome rather than the usual two copies. It occurs in about 1 in 9,000 live births [2]. Trisomy 18 is the second most common genetic disorder and trisomy 13 is the 3rd most common, with trisomy 21 (Down syndrome) being the most common.

Trisomy 13 & 18 are closely related and cause many similar medical issues. Some of the most common birth defects caused by T13 & T18 include congenital heart defects, structural brain abnormalities, facial defects, and kidney problems. They are also often associated with feeding difficulties, skeletal abnormalities, and developmental delays. T13 & T18 generally cause a shortened lifespan and are therefore considered “incompatible with life.” However, with medical advancements, many children can live long lives and individual outcomes are different for every child, because T13/T18 cause a wide range of disorders. The severity of symptoms and outlook is contingent upon the severity of developmental defects along with the level of medical intervention provided.

While trisomy 13 & 18 do cause higher rates of miscarriage and stillbirth and have higher mortality rates after birth, they are far from “lethal.” The one-year survival rates, once thought to be about 5%, are actually closer to 20% now, and survival rates are even higher when given medical interventions [3] [4] [5].

It should also be considered that the stigma of trisomy 13 & 18 being “fatal” leads to very high rates of termination or lack of intervention in live births, which only furthers the bleak statistics attached with these disorders. The more families are told their child is a lost cause, the more children aren’t carried to term or pass away quickly after birth without care, and so the poor statistics continue to be perpetuated. Until we start to give more children a fighting chance, the endless cycle will continue. Often times, hospitals and medical professionals are the ones to discourage or deny care, leaving parents feeling hopeless. Our goal is to empower parents to fight for proper care for their children, and for medical professionals to provide parents with all the options available to them rather than giving up on their children. No matter the outcome or length of live, whether a child lives for minutes or for years, all children are worthy of respect, life and love.

Sources:

1. Trisomy 13 | Pediatrics In Review | American Academy of Pediatrics

2. Trisomy 13 and 18—Prevalence and mortality—A multi‐registry population based analysis - Goel - 2019 - American Journal of Medical Genetics Part A - Wiley Online Library

3. Operative and nonoperative outcomes in patients with trisomy 13 and 18 with congenital heart disease

4. Trends in the survival of patients with trisomy 13 from 1995 to 2021: A population study in Japan - Kato - 2024 - American Journal of Medical Genetics Part A - Wiley Online Library

5. Rethinking the Paradigm: The Evolving Care of Children with Trisomy 13 and 18