[Combined immunodeficiency with cutaneous manifestations associated with DOCK8 mutation]

Area of Science:

• Immunology
• Genetics
• Pediatrics

Background:

• Primary immunodeficiencies often manifest with elevated IgE and viral skin infections.
• Combined immunodeficiency (CID) encompasses a group of disorders affecting cellular and humoral immunity.

Observation:

• A 2-year-old boy presented with severe dermatitis and disseminated molluscum contagiosum.
• The patient exhibited high IgE levels, eosinophilia, and significant TCD8 lymphopenia.

Findings:

• Impaired lymphocyte proliferation and poor antibody response to vaccination were observed.
• Normal ZAP-70 protein, NK cell function, and HLA I levels suggested a specific defect in cytotoxic cells.
• Molecular testing confirmed a mutation in the DOCK8 gene, diagnosing a novel immunodeficiency.

Implications:

• This case highlights DOCK8 deficiency as a cause of combined immunodeficiency with severe cutaneous manifestations.
• Early genetic diagnosis is crucial for managing this rare condition and preventing complications.
• This represents the first reported pediatric case of DOCK8 deficiency in the country, expanding the known clinical spectrum.