Highlights from the article: A diagnosis of combined immunodeficiency was suspected, and molecular genetic investigations were performed on a panel of 37 PID-associated genes following clinical exome sequencing (see Supplementary Methods). A multiplex PCR was optimised to enable amplification of a normal-allele-specific fragment in conjunction with the deletion-specific allele. Other investigators have used targeted amplification of gene-specific transcripts for RNA sequencing, in order to confirm molecular diagnoses in patients with either cystic fibrosis or primary ciliary dyskinesia [[8]].