- Ailments entailing substantial increases in sensitivity and side effect risk from radiation therapy (ataxia telangiectasia, Nijmegen breakage syndrome, and human immunodeficiency virus (HIV) with CD4 count < 200 cells/microliter); HIV testing is not required for eligibility for this protocol, and known HIV positive patients are eligible, provided they are under treatment with highly active antiretroviral therapy (HAART) and have a CD4 count >= 200 cells/microliter within 30 days prior to step 2 registration