XLA

Boy form → X-linked (affects boys)

Broken key on chest → BTK gene mutation

Keyhole symbol → Blocked B-cell maturation

Hollow limbs → No B cells, decreased all immunoglobulins

Flat neck → No lymph nodes or tonsils

Floating microbes → Recurrent bacterial and enteroviral infections (after 6 months)

"✖️ LIVE" tag → Live vaccines contraindicated