Novel pathological genetic variant associated with DOCK8 deficiency: case report with successful hematopoietic stem cell transplantation


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Citlak H. K., Turkyilmaz A., KOT H., Koc F. S. M., Saglam K. A., Celik S. C., ...Daha Fazla

Allergologia et Immunopathologia, cilt.54, sa.4, ss.144-150, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 54 Sayı: 4
  • Basım Tarihi: 2026
  • Doi Numarası: 10.15586/aei.v54i4.1585
  • Dergi Adı: Allergologia et Immunopathologia
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, MEDLINE, DIALNET, Health Research Premium Collection (ProQuest)
  • Sayfa Sayıları: ss.144-150
  • Anahtar Kelimeler: DOCK8 deficiency, hematopoietic cell transplantation, hyper-IgE, inborn errors of immunity
  • Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

Deficiency of dedicator of cytokinesis 8 (DOCK8) is a combined immunodeficiency characterized by severe atopic dermatitis, recurrent infections, and elevated serum immunoglobulin E (IgE) levels. Following genetic confirmation, early hematopoietic stem cell transplantation (HSCT) is the treatment of choice. We report a 7-year-old girl who presented with refractory atopic dermatitis and recurrent sinopulmonary infections. Laboratory evaluation revealed markedly elevated total IgE, lymphopenia, decreased memory B cells, and poor vaccine responses. Whole exome sequencing identified a previously unreported homozygous nonsense mutation in the DOCK8 gene (c.5382C>A; p.Tyr1794*). Functional validation was achieved through flow cytometry, which demonstrated significantly reduced DOCK8 protein expression. The patient underwent successful HSCT from a fully matched (10/10) HLA-compatible donor following conditioning with fludarabine and treosulfan. At 1 year follow-up, full donor chimerism was achieved, and the patient remained in remission. This case highlights a novel pathogenic variant in DOCK8 deficiency and demonstrates curative success following definitive diagnosis and timely HSCT.