Childhood Cancer Predisposition Study (CCPS)

Inclusion Criteria: Primary Subjects must meet all of the below criteria to be eligible for enrollment: 1. Be less than 21 years of age at the time of enrollment 2. Have a diagnosis of a specific CPS, whether they have had cancer or not * Based on clinical laboratory testing demonstrating a Pathogenic or Likely Pathogenic germline variant and/or * Based on well-established clinical diagnostic criteria and/or * Based on high clinical suspicion of a specific CPS with clinical laboratory testing demonstrating a variant of uncertain significance (VUS) Affected Parents must meet all of the following criteria to be eligible for enrollment: 1. Be the biologic parent of a Primary Subject and 2. Carry a diagnosis (or obligate diagnosis) of the familial CPS Adult Affected Siblings must meet all of the following criteria to be eligible for enrollment: 1. Be the biologic sibling of a Primary Subject and 2. Carry a diagnosis (or obligate diagnosis) of the familial CPS Unaffected Parents and Siblings must meet all of the following criteria to be eligible for enrollment 1. Be the biologic parent or sibling of a Primary Subject and 2. Not carry a diagnosis (or obligate diagnosis) of the familial CPS Affected Family Members must meet all of the following criteria to be eligible for enrollment: 1\. Carry a diagnosis of (or obligate diagnosis of) the familial CPS. Documentation is requested but not required. More than one child from a Primary Family Unit may be a Primary Subject. An Unaffected Sibling may be reclassified as a Primary Subject if diagnosed with a CPS during childhood. Exclusion Criteria: * Individuals with a strong personal or family history of cancer without a genetic or clinical diagnosis of a specific CPS are not eligible for enrollment.