Dergi makalesi Açık Erişim

Expanding the clinical and immunological phenotypes of PAX1-deficient SCID and CID patients

2023    Yakici, Nalan; Kreins, Alexandra Y.; Catak, Mehmet Cihangir; Babayeva, Royala; Erman, Baran; Kenney, Heather; Gungor, Hatice Eke; Cea, Pablo A.; Kawai, Tomoki; Bosticardo, Marita; Delmonte, Ottavia Maria; Adams, Stuart; Fan, Yu-Tong; Pala, Francesca; Turkyilmaz, Ayberk; Howley, Evey; Worth, Austen; Kot, Hakan; Sefer, Asena Pinar; Kara, Altan

Paired box 1 (PAX1) deficiency has been reported in a small number of patients diagnosed with otofaciocervical syndrome type 2 (OFCS2). We described six new patients who demonstrated variable clinical penetrance. Reduced transcriptional activity of pathogenic variants confirmed partial or complete PAX1 deficiency. Thymic aplasia and hypoplasia were associated with impaired T cell immunity. Corrective treatment was required in 4/6 patients. Hematopoietic stem cell transplantation resulted in poor immune reconstitution with absent naive T cells, contrasting with the superior recovery of T cell immunity after thymus transplantation. Normal ex vivo differentiation of PAX1-deficient CD34+ cells into mature T cells demonstrated the absence of a hematopoietic cell-intrinsic defect. New overlapping features with DiGeorge syndrome included primary hypoparathyroidism (n = 5) and congenital heart defects (n = 2), in line with PAX1 expression during early embryogenesis. Our results highlight new features of PAX1 deficiency, which are relevant to improving early diagnosis and identifying patients requiring corrective treatment.