OBJECTIVE To assess the potential performance of screening for fetal trisomies 21, 18 and 13 by cell-free DNA (cfDNA) analysis of maternal blood using the IONA® test. METHODS This was a nested case-control study of cfDNA analysis of maternal plasma using the IONA test. Samples were obtained at 11-13 weeks' gestation, before chorionic villus sampling, from 201 euploid pregnancies, 35 with tris...

The trisomy 18 syndrome, also known as Edwards syndrome, is a common chromosomal disorder due to the presence of an extra chromosome 18, either full, mosaic trisomy, or partial trisomy 18q. The condition is the second most common autosomal trisomy syndrome after trisomy 21. The live born prevalence is estimated as 1/6,000-1/8,000, but the overall prevalence is higher (1/2500-1/2600) due to the ...

The Edwards' syndrome phenotype results from full, mosaic or partial trisomy 18q. Full trisomy 18 is the most common form occurring in about 94% of cases. In full trisomy every cell contains three full copies of chromosome 18. Mosaics can occur in about 5% of cases in which some cells are normal with 46 chromosomes and others have the extra chromosome. Partial trisomy 18 can (rarely) occur if a...

BACKGROUND Trisomy 18 (Edwards' syndrome, T18) is the second most common trisomy in man. We describe 118 children with regular T18 who were ascertained clinically and cytogenetically in the Kuwait Medical Genetics Centre during 1980-1997. METHODS Ascertainment of T18 cases was performed shortly after birth. Chromosomal studies were carried out in addition to other relevant investigations. To ...

The Edwards' syndrome phenotype results from full, mosaic or partial trisomy 18q. Full trisomy 18 is the most common form occurring in about 94% of cases. In full trisomy every cell contains three full copies of chromosome 18. Mosaics can occur in about 5% of cases in which some cells are normal with 46 chromosomes and others have the extra chromosome. Partial trisomy 18 can (rarely) occur if a...

John Hilton Edwards [7] first described the symptoms of the genetic disorder known as Trisomy 18?one of the most common forms of human trisomy, which occurs when cells have an extra copy of a chromosome, in 1960. Trisomy 18 [5], also known as Edwards Syndrome [6], occurs approximately once per 6000 live births and is second in frequency only to Trisomy 21, or Down?s Syndrome, as an autosomal tr...

OBJECTIVE To investigate the maternal serum concentration of human placental growth hormone (hPGH) in trisomy 21 and trisomy 18 pregnancies at 11 to 13 weeks of gestation and to examine the possible association between fetal nuchal translucency (NT) thickness and maternal serum free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A). METHODS The m...