2024年2月28日 · Trisomy 18 is a condition caused by a problem in your chromosomes. It's also called Edwards syndrome, after the doctor who first described it. Chromosomes are the threadlike structures in cells...

Trisomy 18 is a chromosome disorder characterized by having 3 copies of chromosome 18 instead of the usual 2 copies.

Trisomy 18 happens when there is an extra copy of chromosome 18 in either the egg or the sperm before conception. This means that the baby will have three copies of chromosome 18 instead of two. The extra chromosome can cause differences in the way a baby develops. Most often, trisomy 18 happens by chance.

Trisomy 18 is lethal in utero (95%) or within the first year of life (< 90%) for most affected individuals. Most surviving individuals are non-ambulatory and exhibit severe intellectual disability with limited communication skills. Free T18 is found in around 95% of cases.

Showing that intensive care for T18 infants improves the survival and survival-discharge rates compared to non-intensive care, our results suggest that T18 is no longer a uniformly lethal disease, as T18 infants are capable of being discharged home.

Chromosome 18 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 18 spans about 80 million base pairs (the building material of DNA) and represents about 2.5 percent of the total DNA in cells. The following are some of the gene count estimates of human chromosome 18.

The Single-nucleotide-polymorphism-based Microdeletion and Aneuploidy RegistTry (SMART) was a large prospective study designed to evaluate cfDNA performance for the 22q11.2 deletion syndrome and the common trisomies (trisomy 21 [T21], trisomy 18 [T18], and trisomy 13 [T13]) in a general referral population.

2023年5月20日 · Trisomy 18 syndrome (T18) is the second most common autosomal trisomy and has a high risk of fetal loss and stillbirth. The prevalence in live births is estimated as 1/6,000–1/8,000. However, the actual prevalence may be higher (1/2,500–1/2,600) because of the high risk of fetal death and pregnancy termination after prenatal diagnosis [1].

2020年6月5日 · Cell-free fetal DNA (cffDNA) has opened up new approaches for non-invasive prenatal testing (NIPT), and it is often used as the second-tier test for high-risk pregnant women in detecting trisomy (T) 21, T18, and T13 after serum biochemistry screening.

Infants with T13 or T18 at CHNC NICUs represent a select group for whom parents may have desired more intensive treatment. Survival to NICU discharge was possible, and surviving infants had a longer hospital stay and needed more discharge supports.