TCF3 and agammaglobulinemia: We suggest that it is caused by the p.Asp70Asn missense variant that affects a highly conserved nucleotide in the transcription factor 3 (TCF3) gene, also known as E2A. In men, mutations in this gene are associated with agammaglobulinemia 8 (OMIM #616941) (see Additional file 6: Table S5).