Features include failure to thrive, dehydration
from chronic diarrhea, eczema from graft-versus-host disease (Omenn
syndrome), lymphadenopathy and hepatosplenomegaly (Omenn syndrome or Bare
Lymphocyte syndrome), neurological sequelae, and developmental regression
(not caused by infections but genetic in PNP deficiency). Main causes of
infections are Pneumocystis carinii, atypical mycobacterium, herpes viruses (generalized
herpetic infections), Candida (and other systemic fungal infections),
Cryptosporidium, and Pneumococcus.