Case#: P1, 13 year old boy

DiseaseAssertion: APDS

FamilyInfo: no relevant family history was reported.

CaseHPOFreeText: He presented with hypogammaglobulinemia with decreased IgG and IgA but normal IgM serum levels (Table 1). Current complications include bronchiectasis, a lymphoproliferative syndrome with splenomegaly and hepatic fibrosis responsible for portal hypertension associated with gastrointestinal bleedings.

CasePreviousTesting: Thus, mutations known to cause APDS1 or APDS2 were searched and excluded by Sanger sequencing.

GenotypingMethod: Subsequently, to identify the genetic cause of the disease, whole exome sequencing was performed in P1. A heterozygous G to A mutation at position 9775698 (GRCh37; NM_005026.3) on chromosome 1, c.241 G>A in the PIK3CD gene was detected.

Variant: The variation encodes an amino acid substitution from glutamic acid to lysine at position 81 (E81K) located in the ABD at the N-terminal part of p110δ (Figure 1A). Sanger sequencing confirmed the mutation in the patient, which was not present in either parents.

CAID: CA338300169

gnomAD: absent from gnomAD v2.1.1