Genetic variation at a splicing branch point in intron 7 of STK11: a rare variant decreasing its expression in a Chinese family with Peutz-Jeghers syndrome.
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引用次数: 0
Abstract
Background: Peutz-Jeghers syndrome (PJS), a rare dominantly inherited disease, is primarily characterized by hamartomatous polyps and melanotic macules as well as by an increased risk of cancer. The current study aimed to identify the pathogenic gene and pathogenic mechanism of a proband with PJS, thereby offering precise prevention and treatment strategies for PJS.
Methods: A detailed clinical examination was performed of the proband diagnosed with PJS and her family members. In addition, peripheral venous blood was collected from the family members to extract genomic DNA. The pathogenic genes of the proband were identified using whole-exome sequencing, and the candidate pathogenic variants were verified via Sanger sequencing. Meanwhile, co-segregation tests were performed among six family members. Finally, reverse transcription-polymerase chain reaction (RT-PCR) was performed to assess transcript variants in the peripheral blood cells of patients and non-related healthy controls.
Results: Genetic testing revealed a rare splicing variant c.921-1G > C in STK11 in the proband and in her sister and nephew, and the variant co-segregated among the affected family members and nonrelated healthy controls. The proband phenotypically presented with a rare gastric-type adenocarcinoma of the cervix. RT-PCR revealed that the STK11 c.921-1G > C variant could produce two transcripts. Of note, 40 base pairs were deleted in the aberrant transcript between exons 3 and 4, resulting in a frameshift variant and premature termination of the amino acid in exon 6 and ultimately leading to the loss of its functional domain in the STK11 protein. Finally, RT-PCR showed that compared with healthy controls, STK11 mRNA expression level was < 50% in patients.
Conclusion: The present study results indicated that the rare splicing variant c.921-1G > C in intron 7 of STK11 may be a pathogenic variant in patients with PJS. However, this variant (in intron 7) may not produce abnormal transcripts (deletion of 40 base pairs between exons 3 and 4), and PJS may be attributed to the decrease in STK11 expression. Therefore, this study emphasized the importance of genetic counseling, pre-symptomatic monitoring, and early complication management in PJS.
期刊介绍:
World Journal of Surgical Oncology publishes articles related to surgical oncology and its allied subjects, such as epidemiology, cancer research, biomarkers, prevention, pathology, radiology, cancer treatment, clinical trials, multimodality treatment and molecular biology. Emphasis is placed on original research articles. The journal also publishes significant clinical case reports, as well as balanced and timely reviews on selected topics.
Oncology is a multidisciplinary super-speciality of which surgical oncology forms an integral component, especially with solid tumors. Surgical oncologists around the world are involved in research extending from detecting the mechanisms underlying the causation of cancer, to its treatment and prevention. The role of a surgical oncologist extends across the whole continuum of care. With continued developments in diagnosis and treatment, the role of a surgical oncologist is ever-changing. Hence, World Journal of Surgical Oncology aims to keep readers abreast with latest developments that will ultimately influence the work of surgical oncologists.