Genetic testing is routinely performed on infants with critical congenital heart disease (CHD). This project reviewed the effect of implementing a genetic testing protocol in this population. Charts of infants with critical CHD were reviewed for genetic testing and results across two time periods: the time before implementation of a genetic testing protocol (pre-protocol) and the time after implementation (post-protocol). The use of karyotype, 22q11.2 Deletion testing, and chromosomal microarray were compared across these two time periods. Records of 891 infants were reviewed. 562 (63%) had at least one of the target genetic tests completed. During the pre-protocol time period, 66% of patients who had genetic testing underwent multiple tests versus 24% during the post-protocol time period (p < 0.01). The rate of patients who underwent genetic testing increased from 60% in the pre-protocol time period to 77% in the post-protocol time period (p < 0.01). The rate of diagnosis of genetic conditions during the pre-protocol period was 26% versus 36% during the post-protocol period (p = 0.01). There was a reduction in cost to patients by $5105.59 per diagnosis during the post-protocol period. Patients with critical CHD in the post-protocol period were less likely to undergo multiple genetic tests and more likely to have a diagnosis of genetic disease. In addition there was a significant reduction in cost per diagnosis during the post-protocol time period. Genetic testing protocols for infants with critical CHD promoted more efficient use of genetic testing and increased the rate of diagnosis of genetic conditions in this population.
Keywords: 22q11.2 Deletion syndrome; Congenital heart disease; Genetic testing; Microarray.