25th May 2025

An 8-month-old boy presents with recurrent infections, including diarrhoea and otitis media, since he was three months old.

An 8-month-old boy presents with recurrent infections, including diarrhoea and otitis media, since he was three months old. Growth chart examination reveals failure to thrive with the baby being at <5th centile for height and weight. No neurological symptoms were noted. Examination revealed lymphadenopathy with hepatosplenomegaly. Blood tests reveal reduced immunoglobulins and reduced T-cell and B-cell lymphocyte populations. Chest X-ray showed an absent thymic shadow.

What is the underlying diagnosis?

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