16th February 2024

A 6-month-old female is reviewed in the immunology clinic after her most recent admission

A 6-month-old female is reviewed in the immunology clinic after her most recent admission to hospital with pneumonia. She has had multiple admissions of pneumonia and otitis media. Urine cultures grew Candida spp. Her sputum cultures grew Pneumocystis jirovecii. Her blood tests showed lymphopenia with normal haemoglobin and platelet levels. Chest X-rays reveal an absent thymic shadow. Blood tests show reduced B-cell and T-cell lymphocyte populations with reduced immunoglobulins.

Which of the following diagnoses is most likely?

Select the SINGLE most appropriate option from the list below. Select ONE option only.