ABSTRACT
Objective: Noninvasive prenatal testing (NIPT) for fetal aneuploidies has been widely adopted in developed countries. Despite the sharp decrease in the cost of massively parallel sequencing, the technical know-how and skilled personnel are still one of the major limiting factors for applying this technology to NIPT in low-income settings. Here, we present the establishment and validation of our NIPT procedure called triSure for detection of fetal aneuploidies. Methods: We established the triSure algorithm based on the difference in proportion of fetal and maternal fragments from the target chromosome to all chromosomes. Our algorithm was validated using a published data set and an in-house data set obtained from high-risk pregnant women in Vietnam who have undergone amniotic testing. Several other aneuploidy calling methods were also applied to the same data set to benchmark triSure performance. Results: The triSure algorithm showed similar accuracy to size-based method when comparing them using published data set. Using our in-house data set from 130 consecutive samples, we showed that triSure correctly identified the most samples (overall sensitivity and specificity of 0.983 and 0.986, respectively) compared to other methods tested including count-based, sized-based, RAPIDR and NIPTeR. Conclusions: We have demonstrated that our triSure NIPT procedure can be applied to pregnant women in low-income settings such as Vietnam, providing low-risk screening option to reduce the need for invasive diagnostic tests.
Subject(s)
Aneuploidy , Cell-Free Nucleic Acids/analysis , Noninvasive Prenatal Testing/methods , Adult , Algorithms , Case-Control Studies , Cell-Free Nucleic Acids/blood , Chromosomes, Human, Pair 13/genetics , Chromosomes, Human, Pair 18/genetics , Chromosomes, Human, Pair 21/genetics , Female , High-Throughput Nucleotide Sequencing/methods , Humans , Middle Aged , Pregnancy , Sequence Analysis, DNA/methods , Trisomy/diagnosis , Trisomy/genetics , Vietnam , Young AdultABSTRACT
BACKGROUND: Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary syndrome characterised by the development of hundreds to thousands of adenomatous colonic polyps during the second decade of life. FAP is caused by germ line mutations in the adenomatous polyposis coli (APC) gene located on chromosome 5q21-22. CASE PRESENTATION: A 36-year-old female was presented with 100-1000 adenomatous colonic polyps, typical of classic FAP symptoms. Genetic testing using massively parallel sequencing identified a 5-bp deletion (c.3927_3931delAAAGA) which causes frameshift (p.Glu1309Aspfs) and creates a premature stop codon, resulting in the replacement of the last 1535 amino acids of APC by five incorrect amino acids. Two of the proband's four siblings also exhibited classic FAP symptoms and carried the same 5-bp heterozygous deletion in the APC gene. One of the proband's two nephews also tested positive for this mutation but has not been examined by endoscopy due to his young age. CONCLUSIONS: We reported here for the first time the use of massively parallel sequencing (MPS)-based genetic testing to identify a germline mutation within a three-generation Vietnamese family. This mutation is most likely responsible for the development of FAP.
Subject(s)
Adenomatous Polyposis Coli Protein/genetics , Adenomatous Polyposis Coli/diagnosis , Adenomatous Polyposis Coli/genetics , Frameshift Mutation , Heterozygote , Adenomatous Polyposis Coli/ethnology , Adenomatous Polyposis Coli/surgery , Adult , Asian People , Child, Preschool , Chromosomes, Human, Pair 5/chemistry , Colectomy/methods , Female , Gene Expression , Genetic Testing , High-Throughput Nucleotide Sequencing , Humans , Male , Middle Aged , Pedigree , Siblings , VietnamABSTRACT
A novel and efficient method for the synthesis of selenophenes is disclosed. Selenophenes were synthesized in high yields in a single operation from 1,3-dienes containing a carbonyl group at the C-1 position and selenium dioxide. The bidirectional synthesis of selenophenes can also be demonstrated using this method. The selenophene is believed to form via a [4 + 2] cycloaddition between diene and selenium dioxide.
Subject(s)
Alkenes/chemistry , Organoselenium Compounds/chemical synthesis , Selenium Compounds/chemistry , Chromatography, Thin Layer , Combinatorial Chemistry Techniques , Cyclization , Molecular Structure , Selenium OxidesABSTRACT
[formula: see text] An efficient and unique route to the 5-7-6 core of guanacatepene A (1) is described. The installation of the desired stereochemistry at the C8 position was achieved via the desymmetrization of the cyclohexadienone by reductive ring closure of the seven-membered ring. That the closure of the seven-membered ring produced only the desired isomer is hypothesized to be a result of the more stable trans relationship between the C8 and C11 methyl groups.
