Early onset of colorectal cancer in a 13-year-old girl with Lynch syndrome

Abstract

Lynch syndrome is the most common inherited colon cancer syndrome. Patients with Lynch syndrome develop a range of cancers including colorectal cancer (CRC) and carry a mutation on one of the mismatched repair (MMR) genes. Although CRC usually occurs after the fourth decade in patients with Lynch syndrome harboring a heterozygous MMR gene mutation, it can occur in children with Lynch syndrome who have a compound heterozygous or homozygous MMR gene mutation. We report a case of CRC in a 13-year-old patient with Lynch syndrome and congenital heart disease. This patient had a heterozygous mutation in MLH1 (an MMR gene), but no compound MMR gene defects, and a K-RAS somatic mutation in the cancer cells.

Pediatric manifestations of Lynch Syndrome: A single center experience

“…The patient with a family history of Lynch syndrome had not undergone screening or genetic testing prior to cancer diagnosis. This case series adds to the very limited literature describing cases of pediatric colorectal cancer associated with Lynch syndrome [ 9 , 10 ].…”

High-sensitivity microsatellite instability assessment for the detection of mismatch repair defects in normal tissue of biallelic germline mismatch repair mutation carriers

“…In addition, the result obtained with a CMMRD individual’s oral mucosa sample suggests its potential for the analysis of MSI in minimally invasive samples, patients with lymphopenia or after allogenic bone marrow transplant. Moreover, the hs-MSI approach is able to robustly discriminate between CMMRD and LS, Li-Fraumeni, NF1 and PPAP, which may assist in classifying cases with overlapping phenotype 4 5…”

“…Constitutional mismatch repair deficiency (CMMRD; OMIM #276300) is a rare devastating cancer syndrome caused by biallelic germline mutations in the same genes and mainly characterised by the development of haematological, brain and colorectal tumours during childhood and adolescence 2 3. Overlapping phenotypes have been described between LS and CMMRD,4 5 as well as between CMMRD and other cancer syndromes such as neurofibromatosis type 1 (NF1), polymerase proofreading-associated polyposis (PPAP) and Li-Fraumeni 6 7…”

A mismatched syndrome: A five‐year‐old girl with very‐high‐risk leukemia and Lynch syndrome

“…Children primarily develop brain tumors, colon cancer, or leukemia. 2 The youngest patient described in the literature to date with an LS-related cancer was a 13-year-old with colorectal cancer. 3 Here, we report the case of a young child with very-high-risk precursor B-cell acute lymphoblastic leukemia (ALL) found to have LS.…”