Table 2.

The costs of tiered NGS (targeted panel followed by WES in unsolved cases) vs WES-only approach will differ, based on the pretest probability of monogenic PIDs within the population.

Comparative costs of NGS in a population with a high prevalence of monogenic PIDs: In a highly consanguineous population, such as the one used in this study, a monogenic cause of PID is more likely to be found by NGS. For these types of populations, we have used the diagnostic yield found in our study population (56%).
	Tiered approach	WES-only
NGS panel $1700 per patient	100 patients × $1700	Not applicable
WES $2500 per patient	44 patients × $2500	100 patients × $2500
Final cost per patient	$2,800	$2,500
Savings per patient	$2800 – $2500 = $300
Comparative costs of NGS in a population with a lower prevalence of monogenic PIDs. Previously published studies have achieved a diagnostic yield of 25 – 45% with NGS in non-consanguineous populations.1,2,10,11 For this population, we have used a NGS diagnostic yield of 30%.
	Tiered approach	WES-only
NGS panel $1700 per patient	100 patients × $1700	Not applicable
WES $2500 per patient	70 patients × $2500	100 patients × 2500
Final cost per patient	$3,450	$2,500
Savings per patient	$3450 – $2500 = $950