Detection of Germline Mutations in a Cohort of 250 Relatives of Mutation Carriers in Multigene Panel: Impact of Pathogenic Variants in Other Genes beyond BRCA1/2

BACKGROUND

Several hereditary-familial syndromes associated with various types of tumors have been identified to date, evidencing that hereditary cancers caused by germline mutations account for 5-10% of all tumors. Advances in genetic technology and the implementation of Next-Generation Sequencing (NGS) have accelerated the discovery of several susceptibility cancer genes, allowing for the detection of cancer-predisposing mutations in a larger number of cases. The aim of this study is to highlight how the application of an NGS-multigene panel to a group of oncological patients subsequently leads to improvement in the identification of carriers of healthy pathogenic variants/likely pathogenic variants (PVs/LPVs) and prevention of the disease in these cases.

METHODS

Starting from a total of 110 cancer patients carrying PVs/LPVs in genes involved in cancer susceptibility detected via a customized NGS panel of 27 cancer-associated genes, we enrolled 250 healthy collateral family members from January 2020 to July 2022. The specific PVs/LPVs identified in each proband were tested in healthy collateral family members via Sanger sequencing.

RESULTS

A total of 131 out of the 250 cases (52%) were not carriers of the mutation detected in the affected relative, while 119 were carriers. Of these, 81/250 patients carried PVs/LPVs on BRCA1/2 (33%), 35/250 harbored PVs/LPVs on other genes beyond BRCA1 and BRCA2 (14%), and 3/250 (1%) were PVs/LPVs carriers both on BRCA1/2 and on another susceptibility gene.

CONCLUSION

Our results show that the analysis of BRCA1/2 genes would have only resulted in a missed diagnosis in a number of cases and in the lack of prevention of the disease in a considerable percentage of healthy carriers with a genetic mutation (14%).

GEM detector performance with innovative micro-TPC readout in high magnetic field

Gas detector development is one of the pillars of the research in fundamental physics. Since several years, a new concept of detectors, called Micro Pattern Gas Detector (MPGD), allowed to overcome several problems related to other types of commonly used detectors, like drift chamber and micro strips detectors, reducing the rate of discharges and providing better radiation tolerance. Among the most used MPGDs are the Gas Electron Multipliers (GEMs). Invented by Sauli in 1997, nowadays GEMs have become an important reality for particle detectors in high energy physics. Commonly deployed as fast timing detectors and triggers, their fast response, high rate capability and high radiation hardness make them also suitable as tracking detectors. The readout scheme is one of the most important features in tracking technology. Analog readout based on the calculation of the center of gravity technique allows to overcome the limit imposed by digital pads, whose spatial resolution is limited by the pitch dimensions. However, the presence of high external magnetic fields can distort the electronic cloud and affect the performance. The development of the micro-TPC reconstruction method brings GEM detectors into a new prospective, improving significantly the spatial resolutionin presence of high magnetic fields. This innovative technique allows to reconstruct the 3-dimensional particle position, as Time Projection Chamber, but within a drift gap of a few millimeters. In these report, the charge centroid and micro-TPC methods are described in details. We discuss the results of several test beams performed with planar chambers in magnetic field. These results are one of the first developments of micro-TPC technique for GEM detectors, which allows to reach unprecedented performance in a high magnetic field of 1 T.

Chronic respiratory disease in mining communities in Marion County, West Virginia

A study of respiratory disease has been carried out in five mining communities in Marion County, West Virginia, United States of America. Each of the five communities was defined by a private census. A questionnaire on respiratory symptoms, chest and other illnesses, smoking habits, and occupation was completed on all adults aged 20 years and over. All men aged 20-69 who lived in three of the towns were asked to attend at a centre for examination and 83% responded. The examination included the completion of a further questionnaire on respiratory symptoms, occupation, and smoking habits; examination of the chest; simple tests of ventilatory lung function; and a 14 × 17 in. postero-anterior radiograph of the chest. The prevalence of pneumoconiosis in these communities was low. In one of the three towns a pottery had operated intermittently in the past, giving rise to the possibility of pottery as well as mine dust exposure. Approximately 10-15% of miners and ex-miners aged 50-69 who had never worked in the pottery had category 1 or over pneumoconiosis. Only four cases of progressive massive fibrosis were found in this group, all in men aged 60 years and over. Pneumoconiosis was diagnosed only in men who had worked for 20 years or more underground. Among a group of potters who had never worked in mining the prevalence of pneumoconiosis was higher than in the miners and ex-miners, 27% in the 50-59 age group and 18% in the 60-69 age group being affected. The prevalence of symptoms was not appreciably higher in the miners and the ex-miners than in the non-miners except in the oldest decennial group where a somewhat higher prevalence of cough, breathlessness, and chest illness was noted. A significantly lower average forced expiratory volume in one second (F.E.V._1·0) was also found in this group. A higher prevalence of breathlessness, chest illness, and chronic bronchitis was found in non-miners who had worked in the pottery, and this increased prevalence was associated with a lower mean F.E.V._1·0. Smokers recorded a higher prevalence of symptoms, particularly cough and sputum, than non-smokers. Significantly lower mean F.E.V._1·0 values were found in smokers than in non-smokers aged 50 years and over. There was an association between the educational level attained and both the prevalence of symptoms and the F.E.V._1·0. Those with lower educational grades had a significantly higher prevalence of symptoms, especially cough and sputum. Those who had completed one year or more in college recorded higher F.E.V._s. These differences are the subject of further study. Differences in the prevalence of persistent cough, sputum or breathlessness between communities studied in the United States and the United Kingdom are small or absent. Bronchitic chest illnesses during the three years before interview, particularly those which recurred, appear however to be more common in Britain, and this may explain at least partly the greater disability and mortality from chronic respiratory disease in the United Kingdom than in the United States.