Rare compound heterozygous mutations in gene MSH6 cause constitutive mismatch repair deficiency syndrome

Key Clinical Message Few studies reported patients who harbored three kinds of primary tumors simultaneously. Here, we present a 9‐year‐old boy with colon carcinoma, brain medulloblastoma, and lymphoma. Genetic mutation detection was explored with next‐generation sequencing, and compound heterozygous mutations in gene MSH6 c.3103C>T p.Arg1035Ter and c.3261dupC p.Phe1088LeufsTer were discovered. Few studies reported patients who harbored three kinds of primary tumors simultaneously. Here, we present a 9‐year‐old boy with colon carcinoma, brain medulloblastoma, and lymphoma. Genetic mutation detection was explored with next‐generation sequencing, and compound heterozygous mutations in gene MSH6 c.3103C>T p.Arg1035Ter and c.3261dupC p.Phe1088LeufsTer were discovered.