Patients have short stature, failure to thrive,
and suffer from mental retardation. The disease affects the head and neck
(hypertelorism, epicanthic folds, low-set ears, flat nasal bridge,
micrognathia, macroglossia with protrusion of the tongue), gastrointestinal
tract (diarrhea, malabsorption), and immune system (recurrent and prolonged
respiratory tract infections, resulting in chronic bronchitis, and
bronchiectases; maxillary sinusitis, otitis media, cutaneous infections).
Most patients die of infections (pulmonary and/or gastrointestinal) even
before they reach adolescence.