Cytogenomic results following high-chance non-invasive prenatal testing: a UK national audit.

Objective: Non-invasive prenatal testing (NIPT) is increasingly being adopted as a screening test in the UK and is currently accessed through certain National Health Service healthcare systems or by private provision. This audit aims to describe reasons for and results of cytogenomic investigations carried out within UK genetic laboratories following an NIPT result indicating increased chance of cytogenomic abnormality ('high-chance NIPT result').

Method: A questionnaire was sent out to 24 genetics laboratories in the UK and completed by 18/24 (75%).

Second-trimester prenatal diagnosis of Nager syndrome with a deletion including detected by chromosomal microarray.

Nager syndrome is a rare, complex malformation syndrome, for which there is limited information on prenatal genetic testing. Clinical diagnosis of Nager syndrome, which can be caused by deletions encompassing SF3B4 gene, is possible prenatally. Prenatal chromosomal microarray can aid genotype-phenotype correlation in pregnancies with structural abnormalities seen on ultrasound.

Implementation of cell-free DNA-based non-invasive prenatal testing in a National Health Service Regional Genetics Laboratory.

Background: Non-invasive prenatal testing (NIPT) for the detection of foetal aneuploidy through analysis of cell-free DNA (cfDNA) in maternal blood is offered routinely by many healthcare providers across the developed world. This testing has recently been recommended for evaluative implementation in the UK National Health Service (NHS) foetal anomaly screening pathway as a contingent screen following an increased risk of trisomy 21, 18 or 13. In preparation for delivering a national service, we have implemented cfDNA-based NIPT in our Regional Genetics Laboratory.

Prenatal chromosomal microarray testing of fetuses with ultrasound structural anomalies: A prospective cohort study of over 1000 consecutive cases.

Objective: Evaluate the diagnostic yield of prenatal submicroscopic chromosome anomalies using prenatal array comparative genomic hybridisation (aCGH).

Method: Prospective cohort study conducted between March 2013 and June 2017 including fetuses where an elevated nuchal translucency (NT) or structural anomaly was identified on ultrasound and common aneuploidy testing was negative. aCGH was performed using an 8-plex oligonucleotide platform with a genome wide backbone resolution of greater than 200 kb and interpretation in line with American College of Medical Genetics guidance.

Comparing mutation calls in fixed tumour samples between the affymetrix OncoScan® array and PCR based next-generation sequencing.

Background: The importance of accurate and affordable mutation calling in fixed pathology samples is becoming increasingly important as we move into the era of personalised medicine. The Affymetrix OncoScan® Array platform is designed to produce actionable mutation calls in archival material.

Methods: We compared calls made using the OncoScan platform with calls made using a custom designed PCR panel followed by next-generation sequencing (NGS), in order to benchmark the sensitivity and specificity of the OncoScan calls in a large cohort of fixed tumour samples.