High-Grade Brain Tumors in Siblings With Biallelic MSH6 Mutations

Biallelic germline mutations of Constitutional mismatch repair-deficiency syndrome (CMMR-D) genes, MLH1, MSH2, MSH6, and PMS2 are characterized by increased risk of childhood malignancy. We report a case with CMMR-D caused by novel homozygous MSH6 mutations leading to gliomatosis cerebri and T-ALL in an 11-year-old female and glioblastoma multiforme in her 10-year-old brother, both with rapid progression of the diseases. A literature review on brain tumors in CMMR-D families shows that they are treatment-resistant and lead to early death. Identification of patients with CMMR-D is critical, and specific cancer screening programs with early surgery are recommended. Pediatr Blood Cancer 2011;57:1067-1070. (C) 2011 Wiley-Liss, Inc.