PT - JOURNAL ARTICLE AU - Zeinab Ghorbanoghli AU - Mariëtte van Kouwen AU - Birgitta Versluys AU - Delphine Bonnet AU - Christine Devalck AU - Julie Tinat AU - Danuta Januszkiewicz-Lewandowska AU - Consuelo Calvino Costas AU - Edouard Cottereau AU - James C H Hardwick AU - Katharina Wimmer AU - Laurence Brugieres AU - Chrystelle Colas AU - Hans F A Vasen TI - High yield of surveillance in patients diagnosed with constitutional mismatch repair deficiency AID - 10.1136/jmg-2022-108829 DP - 2022 Nov 21 TA - Journal of Medical Genetics PG - jmg-2022-108829 4099 - http://jmg.bmj.com/content/early/2022/11/21/jmg-2022-108829.short 4100 - http://jmg.bmj.com/content/early/2022/11/21/jmg-2022-108829.full AB - 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.All data relevant to the study are included in the article or uploaded as supplementary information.