Somatic Mosaicism in Twins Discordant for Childhood Cancer

PRIMARY OBJECTIVES:

I. To conduct a descriptive study of same sex twins (MZ and DZ) discordant for childhood CNS tumors identified through the Children's Oncology Group Project:EveryChild registry.

II. To compare the prevalence of somatic mosaicism in classic cancer-associated genes in monozygotic (MZ) twins discordant for childhood brain tumors. In our pilot study, we will sequence blood and saliva DNA samples from 25 MZ twin pairs using a panel of 94 known cancer associated genes.

SECONDARY OBJECTIVES:

I. To compare the profile of mutations detected in DNA extracted from pre- and post-treatment blood samples from a subset of CNS tumor patients. The purpose of this aim is to ensure that differences in somatic mosaicism detected in twin pairs are not caused by cancer therapy.

Outline:

Twins with CNS tumors will undergo blood and saliva DNA samples with the goal is to learn more about genetic differences that may lead to CNS tumor development.

Inclusion criteria

• Newly diagnosed patient with CNS tumor or have recurrent disease and enrolled on APEC14B1.
• Patient must have same sex twin. Note: (history of) treatment on a COG therapeutic trial is not required.
• Patients must be diagnosed at < 19 years of age at the time of diagnosis.
• A family is eligible to participate if the twin with the CNS tumor is deceased but has a blood sample banked through APEC14B1.
• All patients and/or their parents or legal guardians must provide informed consent. Assent will be obtained for participants between the ages of 8-17 years.
• All institutional, FDA, and NCI requirements for human studies must be met.