Clinical measurement of cellular DNA damage hypersensitivity in patients with DNA repair defects

Orphanet Journal of Rare Diseases

Torben Ek¹  Sofia Thunström²  Sara Cajander³  C. I. Edvard Smith⁴  Emilie Wahren Borgström⁵  Anders Fasth⁶  Olov Ekwall⁷  Anna Lyytikäinen⁸  Ola Hammarsten⁹  Pegah Johansson⁹ 

[1] Children’s Cancer Centre, Queen Silvia Children’s Hospital, Gothenburg, Sweden;Department of Clinical Genetics, Sahlgrenska University Hospital, Gothenburg, Sweden;Department of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden;Department of Infectious Diseases, Faculty of Medicine and Health, Örebro University, Örebro, Sweden;Department of Infectious Diseases, The Immunodeficiency Unit, Karolinska University Hospital, Huddinge, Stockholm, Sweden;Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden;Department of Infectious Diseases, The Immunodeficiency Unit, Karolinska University Hospital, Huddinge, Stockholm, Sweden;Division of Infectious Diseases, Department of Medicine, Karolinska Institutet, Solna, Stockholm, Sweden;Department of Pediatrics, , Institution of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;Department of Pediatrics, , Institution of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;Department of Rheumatology and Inflammation Research, Gothenburg University, Gothenburg, Sweden;Laboratory of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden;Laboratory of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden;Department of Laboratory Medicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden;

关键词: Cell division assay (CDA);    γ-H2AX;    DNA repair deficiency disorders;    Ionizing radiation sensitivity;    Mitomycin C sensitivity;    Clinical diagnosis;   

DOI  :  10.1186/s13023-022-02199-8

来源: Springer

【 摘 要 】

BackgroundDNA repair deficiency disorders are rare inherited diseases arising from pathogenic (disease-causing) variants in genes involved in DNA repair. There are no standardized diagnostic assays for the investigation of pathological significance of unknown variants in DNA repair genes. We hypothesized that our assays for measuring in vitro patient blood cell hypersensitivity to DNA-damaging agents can be used to establish the pathological significance of unknown variants in DNA repair genes. Six patients with variants in the DNA repair genes PRKDC (two siblings), DCLRE1C (two siblings), NBN, and MSH6 were included. Here, we used the cell division assay (CDA) and the γ-H2AX assay, which were both developed and clinically validated by us, to measure patient cell hypersensitivity in response to ionizing radiation, mitomycin C, cytarabine and doxorubicin.ResultsRadiation hypersensitivity was detected in the two patients with variants in the PRKDC gene (p < 0.0001 for both at 3.5 Gy), and the two patients with DCLRE1C variants (p < 0.0001 at 3.5 Gy for sibling 1 and p < 0.0001 at 1 Gy for sibling 2). The cells from the patients with the PRKDC variant were also deficient in removing γ-H2AX (p < 0.001). The cells from the patient with variants in the NBN gene were hypersensitive to mitomycin C (p = 0.0008) and deficient in both induction and removal of γ-H2AX in response to radiation.ConclusionsThe combination of the CDA and the γ-H2AX assay is useful in investigating the significance of unknown variants in some DNA repair genes.

【 授权许可】

CC BY