G19(P) Genetic anomalies in infants with congenital heart defects: a retrospective observational analysis

Abstract

Background and Aims Congenital heart defects (CHD) are the most common group of congenital malformation. With advanced testing - such as microarray and Next Generation Sequencing (NGS) - applied into routine clinical practice, more genetic anomalies may be detected in infants with CHDs. Aims and Objectives The study was aimed to investigate the association between the congenital heart defects and genetic anomalies. Methods A retrospective observational study included all the infants with a recoded new diagnosis of born CHD between 01/01/2017 and 31/12/2018, from a single tertiary neonatal intensive care unit. The data were recorded from the electronic patient records. For analytic purposes, CHDs cases were divided into 4 categories: critical, serious, significant or non-significant types. Results 229 infants were identified, of which 8 were excluded due either to a lack of follow up or death from non-cardiac causes, which made classification impossible. 93% of infants with critical CHD, and 85% of those with serious CHD, had relevant genetic testing, of which 31% and 41% had positive diagnoses, respectively. Significantly more infants with critical or serious CHD underwent relevant genetic testing than the infants with significant (50%) or non-significant (12%) CHD (p-value Of the 24 infants with critical, serious or significant CHD diagnosed with a CHD related genetic anomaly: 8 were diagnosed with Trisomy 21; 3 with Noonan’s syndrome; 1 with DiGeorge and the remainder with various microdeletions, microdeletions and single nucleotide variants. Conclusions In our cohort, around one-third of the infants with critical and serious heart conditions had underlying genetic defects. The infants with critical and serious heart condition needing surgery or intervention within one year after birth are often tested for the underlying genetic defect. The uptake of genetic testing was far less in infants with significant or minor CHDs.