High Prevalence of Constitutional Mismatch Repair Deficiency in a Pediatric T-cell Lymphoblastic Lymphoma Cohort

Introduction: Constitutional mismatch repair deficiency (CMMRD) is a rare autosomal recessive disease-carrying an increased risk of cancers (pediatric tumors of central nervous system, haemato-lymphoid malignancies along with gastrointestinal (GI) cancer(s), which are usually seen in the second and third decade) leading to syndromic presentation. Causal mutations are detected in DNA mismatch repair (MMR) genes, including MLH1, PMS2, MSH2, and MSH6 that are also known for their established role in Lynch syndrome. We describe a case of CMMRD with an earlier (first decade of life) presentation of mediastinal acute lymphoblastic lymphoma and colorectal malignancy. Case Presentation: A five-year-old boy presented with respiratory complaints, bilateral cervical lymphadenopathy, multiple café au lait macules (CALMs) on the lower back, history of parental consanguinity with the death of three sisters due to brain tumor within 6 months of diagnosis. Computerized tomographic (CT) scan chest revealed a huge mediastinal mass. The patient underwent a trucut-biopsy of the mass. The results were significant for a pre T-cell acute lymphoblastic lymphoma. Suspicion of CMMRD was raised based on a combination of factors described above. A panel of mismatch repair (MMR) proteins was applied on the biopsy tissue that revealed loss of nuclear expression of MLH1 and PMS2 immunostaining in tumor cells with positive external controls. While on maintenance therapy for lymphoma, about a year later, the patient developed sub-acute intestinal obstruction due to a stenosing polypoidal circumferential tumor in the mid-sigmoid colon found on flexible sigmoidoscopy that was followed by endoscopic biopsies and insertion of a fully-covered self-expanding metallic adult biliary stent with a diameter of 10 mm and length of 6 cm leading to immediate relief of obstruction. Biopsies revealed adenocarcinoma with neuroendocrine differentiation. Metastatic tumor deposits were seen in the omentum, anterior abdominal wall, and the left peritoneal wall. Practical Implications: Earlier (first decade) presentation of gastrointestinal malignancy warrants that an earlier screening through radiological scans for any possible tumors and MMR protein expression analysis (loss in tumor plus normal non-tumor cells) are essential in patients having CALMs and family history of pediatric tumors.

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RARE-55. CHALLENGES AND SPECIFIC STRATEGIES FOR CONSTITUTIONAL MISMATCH REPAIR DEFICIENCY SYNDROME IN LOW RESOURCE SETTINGS. ON BEHALF OF THE INTERNATIONAL RRD CONSORTIUM IN LOW RESOURCE SETTINGS PANEL

Neuro-Oncology ◽

10.1093/neuonc/noaa222.765 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii454-iii454

Author(s):

Rejin Kebudi ◽

Nisreen Amayiri N ◽

Malak Abedalthagafi ◽

Asim Noor Rana ◽

Slman Kirmani ◽

...

Keyword(s):

Mismatch Repair ◽

Checkpoint Inhibitors ◽

Immune Therapy ◽

Malignant Gliomas ◽

Mismatch Repair Deficiency ◽

Term Survival ◽

Low Resource Settings ◽

Low Resource ◽

Repair Deficiency ◽

Constitutional Mismatch Repair Deficiency

Abstract Germline biallelic mutations in one of the mismatch repair genes (MSH2/MSH6/MLH1/PMS2 results in constitutional mismatch repair deficiency (CMMRD), a condition associated with multiple tumors arising from multiple organs during childhood, and these individuals rarely reach adulthood. The paucity of information with respect to these conditions leads to mismanagement and may be a factor in the high mortality of patients with CMMRD. Two international consortia, the European CARE4CMMRD, and the international replication repair deficiency (RRD) consortium, are addressing the many challenges associated with this condition. To address specific issues surrounding the management of CMMRD in low and middle income countries (LMIC), a multidisciplinary taskforce of 11 specialists from nine countries was formed. Preliminary conclusions are: 1) Immunohistochemistry for CMMRD should be considered for all patients with suggestive clinical features. In countries where CMMRD is common, malignant gliomas, colon cancers and T cell lymphomas should be stained routinely as the prevalence of CMMRD in these tumors can exceed 40%. 2) Temozolomide should not be used in the management of malignant glioma. By contrast, preclinical studies have suggested increased sensitivity to nitrosoureas. For the management of CMMRD related lymphoma and leukemia, mercaptopurines should not be avoided or discontinued as a part of the standard of care before more data are collected. 3) Management with checkpoint inhibitors should be limited to centers with intensive care units and expertise in complex supportive care to manage side effects of immune therapy. 4) Surveillance protocols have demonstrated long term survival benefits and should be implemented in LMIC.

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The Challenge of Diagnosing Constitutional Mismatch Repair Deficiency Syndrome in Brain Malignancies from Young Individuals

International Journal of Molecular Sciences ◽

10.3390/ijms22094629 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4629

Author(s):

Cristina Carrato ◽

Carolina Sanz ◽

Ana María Muñoz-Mármol ◽

Ignacio Blanco ◽

Marta Pineda ◽

...

Keyword(s):

Brain Tumors ◽

Mismatch Repair ◽

Rare Event ◽

Deficiency Syndrome ◽

Mismatch Repair Deficiency ◽

Malignant Brain Tumors ◽

Repair Deficiency ◽

Clinical Awareness ◽

High Degree ◽

Constitutional Mismatch Repair Deficiency

Biallelic germline mismatch repair (MMR) gene (MLH1, MSH2, MSH6, and PMS2) mutations are an extremely rare event that causes constitutional mismatch repair deficiency (CMMRD) syndrome. CMMRD is underdiagnosed and often debuts with pediatric malignant brain tumors. A high degree of clinical awareness of the CMMRD phenotype is needed to identify new cases. Immunohistochemical (IHC) assessment of MMR protein expression and analysis of microsatellite instability (MSI) are the first tools with which to initiate the study of this syndrome in solid malignancies. MMR IHC shows a hallmark pattern with absence of staining in both neoplastic and non-neoplastic cells for the biallelic mutated gene. However, MSI often fails in brain malignancies. The aim of this report is to draw attention to the peculiar IHC profile that characterizes CMMRD syndrome and to review the difficulties in reaching an accurate diagnosis by describing the case of two siblings with biallelic MSH6 germline mutations and brain tumors. Given the difficulties involved in early diagnosis of CMMRD we propose the use of the IHC of MMR proteins in all malignant brain tumors diagnosed in individuals younger than 25 years-old to facilitate the diagnosis of CMMRD and to select those neoplasms that will benefit from immunotherapy treatment.

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A sensitive and scalable microsatellite instability assay to diagnose constitutional mismatch repair deficiency by sequencing of peripheral blood leukocytes

Human Mutation ◽

10.1002/humu.23721 ◽

2019 ◽

Vol 40 (5) ◽

pp. 649-655 ◽

Cited By ~ 9

Author(s):

Richard Gallon ◽

Barbara Mühlegger ◽

Sören-Sebastian Wenzel ◽

Harsh Sheth ◽

Christine Hayes ◽

...

Keyword(s):

Microsatellite Instability ◽

Mismatch Repair ◽

Peripheral Blood ◽

Peripheral Blood Leukocytes ◽

Mismatch Repair Deficiency ◽

Blood Leukocytes ◽

Repair Deficiency ◽

Constitutional Mismatch Repair Deficiency

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Constitutional mismatch repair-deficiency syndrome presenting as colonic adenomatous polyposis: clues from the skin

Clinical Genetics ◽

10.1111/j.1399-0004.2010.01543.x ◽

2010 ◽

Vol 80 (4) ◽

pp. 394-397 ◽

Cited By ~ 21

Author(s):

KW Jasperson ◽

WS Samowitz ◽

RW Burt

Keyword(s):

Mismatch Repair ◽

Deficiency Syndrome ◽

Adenomatous Polyposis ◽

Mismatch Repair Deficiency ◽

Repair Deficiency ◽

Constitutional Mismatch Repair Deficiency

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Role of video capsule endoscopy in patients with constitutional mismatch repair deficiency (CMMRD) syndrome: report from the International CMMRD Consortium

Endoscopy International Open ◽

10.1055/a-0591-9054 ◽

2018 ◽

Vol 06 (08) ◽

pp. E1037-E1043 ◽

Cited By ~ 1

Author(s):

Y. Shimamura ◽

C. M. Walsh ◽

S. Cohen ◽

M. Aronson ◽

U. Tabori ◽

...

Keyword(s):

Small Bowel ◽

Mismatch Repair ◽

Capsule Endoscopy ◽

Genetic Disorder ◽

Early Adulthood ◽

Video Capsule Endoscopy ◽

Mismatch Repair Deficiency ◽

Repair Deficiency ◽

Report Data ◽

Constitutional Mismatch Repair Deficiency

Abstract Background and study aims Constitutional mismatch repair deficiency (CMMRD) syndrome, also known as biallelic mismatch repair deficiency (BMMRD) syndrome is a rare autosomal-recessive genetic disorder that has a high mortality due to malignancy in childhood and early adulthood. The small bowel phenotype in CMMRD is not well described and surveillance protocols for small bowel cancer have not been well established. This study was conducted to evaluate the usefulness and clinical impact of video capsule endoscopy (VCE) for small bowel surveillance. Patients and methods We retrospectively reviewed the prospectively maintained International CMMRD Consortium database. Treating physicians were contacted and VCE report data were extracted using a standardized template. Results Among 58 patients included in the database, 38 VCE reports were collected from 17 patients. Polypoid lesions were first detected on VCE at a median age of 14 years (range: 4 – 17). Of these, 39 % in 7 patients (15/38) showed large polypoid lesions (> 10 mm) or multiple polyps that prompted further investigations. Consequently, three patients were diagnosed with small bowel neoplasia including one patient with adenocarcinoma. Small bowel neoplasia and/or cancer were confirmed histologically in 35 % of the patients (6/17) who had capsule surveillance and the lesions in half of these patients were initially visualized on VCE. Multiple polyps were identified on eight VCEs that were completed on three patients. Ten VCEs (28 %) were incomplete due to slow bowel transit; none required capsule removal. Conclusions Small bowel surveillance in patients with CMMRD should be initiated early in life. VCE has the potential to detect polyps; however, small bowel neoplasias are often proximal and can be missed, emphasizing the importance of concurrent surveillance with other modalities. Meeting presentations Digestive Disease Week 2017 and World Congress of Pediatric Gastroenterology, Hepatology and Nutrition 2016.

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