Inclusion Criteria:

- Only newly diagnosed cases of ALL and brain cancers (i.e. diagnosed within the
previous 12 months) under the age of 18 years are eligible for this study. These will
include live born infants at term or born prematurely, and any cases we are able to
ascertain from pediatric hematology records.

- Healthy controls of similar age will be recruited.

- The children must have a parent available to be interviewed who speaks English or
Spanish well enough to understand the questionnaire.

Exclusion criteria:

- Subjects with a diagnosis of Down syndrome or other chromosomal disorder, single gene
disorder, or recognized multi-organ syndrome will be excluded.

- Non-residents of Maryland, the District of Columbia, and Virginia will be excluded;
this will avoid the inclusion of out-of-state case families who traveled a long
distance for clinical care, where control sampling would be problematic.