Patient 1: bi-allelic pathogenic PMS2 GVs
Patient 1 was diagnosed with T-lymphoblastic lymphoma (T-LL) at age
three years, Burkitt Lymphoma at 14, and underwent proctocolectomy at 14
due to numerous colonic polyps. These three diagnoses prompted germline
testing, which revealed bi-allelic pathogenic PMS2 variants,
consistent with constitutional mismatch repair deficiency (CMMRD). At
age 16, a changing mole on the right cheek was biopsied, diagnostic of
MM, and treated with wide local excision (WLE). The patient expired a
few months later secondary to relapsed T-LL. Cascade testing identified
that one variant was maternally inherited while the patient’s father did
not undergo testing. These results prompted Lynch Syndrome cancer
screening for his family.