- Other major chronic illnesses: non-skin cancer, cystic fibrosis, bronchiectasis, myelomeningocele, sickle cell anemia, endocrine disease, congenital heart disease, congestive heart failure, stroke, severe hypertension, insulin-dependent diabetes mellitus, renal failure, liver disorders, immunodeficiency state, significant neuro-developmental delay or behavioral disorders (excluding mild attention deficit hyperactivity disorder), or other conditions that would interfere with participation in the study.