High yield of surveillance in patients diagnosed with constitutional mismatch repair deficiency

J Med Genet. 2023 Jul;60(7):679-684. doi: 10.1136/jmg-2022-108829. Epub 2022 Nov 21.

Abstract

Background: Constitutional mismatch repair deficiency (CMMRD) is a rare autosomal recessively inherited syndrome that is caused by biallelic pathogenic variants of the mismatch repair genes. It is characterised by the development of multiple tumours in the first and second decade of life including brain, gastrointestinal and haematological tumours often resulting in early death. In order to improve the prognosis of these patients, the European collaborative group 'care for CMMRD' developed a surveillance programme in 2014 and established a registry of patients with CMMRD in Paris. The aim of the study was to evaluate the outcome of this programme.

Methods: Twenty-two patients with a definitive diagnosis of CMMRD and with at least one follow-up study were selected from the registry. Medical data on the outcome of surveillance were collected from these patients.

Results: During a mean follow-up of 4 years, the programme detected eight malignant tumours including three brain tumours, three upper gastrointestinal cancers and two colorectal cancers. Most tumours could successfully be treated. In addition, many adenomas were detected in the duodenum, and colorectum and subsequently removed. Seven patients developed a symptomatic malignancy, including two brain tumours, one small bowel cancer and four haematological malignancies. At the end of the follow-up, 16 out of 22 patients (73%) who participated in the surveillance programme were still alive.

Conclusion: The study suggests a beneficial effect of surveillance of the digestive tract and brains.

Keywords: genetic predisposition to disease; germ-line mutation.

MeSH terms

  • Brain Neoplasms* / diagnosis
  • Brain Neoplasms* / genetics
  • Colorectal Neoplasms* / diagnosis
  • Colorectal Neoplasms* / epidemiology
  • Colorectal Neoplasms* / genetics
  • DNA Mismatch Repair
  • Follow-Up Studies
  • Humans
  • Mismatch Repair Endonuclease PMS2 / genetics
  • Neoplastic Syndromes, Hereditary* / diagnosis
  • Neoplastic Syndromes, Hereditary* / epidemiology
  • Neoplastic Syndromes, Hereditary* / genetics

Substances

  • Mismatch Repair Endonuclease PMS2

Supplementary concepts

  • Turcot syndrome