Clinical, immunological and molecular profiles of DOCK8 deficiency in six patients from a tertiary care centre in North India.

BACKGROUND

Dedicator of cytokinesis protein 8 (DOCK8) deficiency is an autosomal recessive form of combined immunodeficiency. This rare disorder is characterized by an increased predisposition to allergy, autoimmunity and malignancies.

OBJECTIVES

To analyse clinical, immunological and molecular profiles of patients with DOCK8 deficiency.

METHODS

Clinic records of all patients attending the primary immunodeficiency clinic from 2018 to 2021 were reviewed. Six patients from five families were found to have DOCK8 deficiency.

RESULTS

Median age at diagnosis was 7.5 years (range 2-13), with a male/female ratio of 5 : 1. Among the six patients, recurrent eczematous skin lesions were the predominant cutaneous manifestation, present in five patients (83%). Warts and molluscum contagiosum were evident in two patients (33%) and one patient (16%), respectively. Two patients had recalcitrant prurigo nodularis lesions and two had epidermodysplasia verruciformis-like lesions. Food allergies and asthma were reported by one patient each. Of the six patients, recurrent sinopulmonary infections were detected in five (83%). Epstein-Barr virus-driven non-Hodgkin lymphoma with liver metastases was the only case of malignancy, in a 4-year-old boy. IgE was elevated in all patients. Lymphopenia and eosinophilia were observed in three patients (50%) and five patients (83.3%), respectively. Genetic analysis showed DOCK8 pathogenic variants in all patients: homozygous deletion mutations in two patients, compound heterozygous deletion mutations in one, and homozygous nonsense mutations in two. A novel pathogenic homozygous missense variant in the DOCK8 gene was identified in one patient.

CONCLUSIONS

DOCK8 deficiency should be considered as a possibility in any patient with early onset eczema, cutaneous viral infections and increased predisposition to allergy, autoimmunity and malignancy.