Fig. 2.

Identification of a disease-causing mutation in. Disease severity and complications increased over time with two severe episodes of EBV-associated lymphoproliferation within one year (a). The patient was assessed using a targeted, next-generation sequencing-based gene panel with high on-target coverage (b). A heterozygous mutation in the RHD domain of the NFKB1 gene was identified, leading to a frameshift and a subsequent stop codon (c.491delG; p.G165A*31). The patient’s father was found to be a carrier of the disease (c) and shows an aberrant B cell immunophenotype despite his mild clinical manifestation (Table 1). The mutation leads to reduced phosphorylation of p105 upon stimulation in both index patient (II-1) and father (I-2), resulting in decreased protein levels of p50 (d)