SVEP1 is important for morphogenesis of lymphatic system: Possible implications in lymphedema.

SVEP1, also known as Polydom, is a large extracellular mosaic protein with functions in protein interactions and adhesion. Since Svep1 knockout animals show severe edema and lymphatic system malformations, the aim of this study is to evaluate the presence of SVEP1 variants in patients with lymphedema. We analyzed DNA from 246 lymphedema patients for variants in known lymphedema genes, 235 of whom tested negative and underwent a second testing for new candidate genes, including SVEP1, as reported here. We found three samples with rare heterozygous missense single-nucleotide variants in the SVEP1 gene. In one family, healthy members were found to carry the same variants and reported some subclinical edema. Based on our findings and a review of the literature, we propose SVEP1 as a candidate gene that should be sequenced in patients with lymphatic malformations, with or without lymphedema, in order to investigate and add evidence on its possible involvement in the development of lymphedema.

Rare PECAM1 variants in three families with lymphedema.

PECAM1 is a member of the immunoglobulin superfamily and is expressed in monocytes, neutrophils, macrophages and other types of immune cells as well as in endothelial cells. PECAM1 function is crucial for the development and maturation of B lymphocytes. The aim of this study was to link rare PECAM1 variants found in lymphedema patients with the development of lymphatic system malformations. Using NGS, we previously tested 246 Italian lymphedema patients for variants in 29 lymphedema-associated genes and obtained 235 negative results. We then tested these patients for variants in the PECAM1 gene. We found three probands with rare variants in PECAM1. All variants were heterozygous missense variants. In Family 1, the unaffected mother and brother of the proband were found to carry the same variant as the proband. Lymphoscintigraphy was performed to determine possible lymphatic malformations and showed that in both cases a bilateral slight reduction in the speed and lymphatic clearance of the lower limbs. PECAM1 function is important for lymphatic vasculature formation. We found variants in PECAM1 that may be associated with susceptibility to lymphedema.

Review of the function of SEMA3A in lymphatic vessel maturation and its potential as a candidate gene for lymphedema: Analysis of three families with rare causative variants.

SEMA3A is a semaphorin involved in cell signaling with PlexinA1 and Neuropilin-1 (NRP1) receptors and it is responsible for recruiting dendritic cells into lymphatics. Mutations in the SEMA3A gene result in abnormalities in lymphatic vessel development and maturation. We investigated the association of SEMA3A variants detected in lymphedema patients with lymphatic maturation and lymphatic system malfunction. First, we used NGS technology to sequence the SEMA3A gene in 235 lymphedema patients who carry wild type alleles for known lymphedema genes. We detected three different missense variants in three families. Bioinformatic results showed that some protein interactions could be altered by these variants. Other unaffected family members of the probands also reported different episodes of subclinical edema. We then evaluated the importance of the SEMA3A gene in the formation and maturation of lymphatic vessels. Our results determined that SEMA3A variants segregate in families with lymphatic system malformations and recommend the inclusion of SEMA3A in the gene panel for testing of patients with lymphedema.

Italian SARS-CoV-2 patients in intensive care: towards an identikit for subjects at risk?

OBJECTIVE: To investigate patient characteristics and factors that increase the risk of being admitted to intensive care and that influence survival in cases of SARS-CoV-2 pneumonia. PATIENTS AND METHODS: One-hundred and ninety-one SARS-CoV-2 patients were admitted to the "Fondazione Poliambulanza di Brescia" Hospital (Brescia, Lombardy, Italy) in the period 1st March 2020 to 11th April 2020. Data on demographics, clinical presentation at admission, co-morbidities, pharmacological treatment, admission to intensive care and death was recorded. Logistic regression and survival analysis were carried out to investigate the risk of being admitted to intensive care and the risk of death. RESULTS: The mean age of the study cohort was 64.6±9.9 years (range 20-88). Median BMI was 28.5±5 kg/m2. Fever (81%) and dyspnea (65%) were the most common symptoms on admission. Most of patients (63%) had at least one co-existing disease. The 157 (82%) patients admitted to intensive care were more likely to be of intermediate age (60-69 years; OR 3.23, 95% CI 1.32-8.38), overweight (OR 2.66, 95% CI 1.02-7.07) or obese (OR 5.63, 95% CI 1.73-21.09) and with lymphocytopenia (OR 2.75, 95% CI 1.17-6.89) than the 34 patients admitted to the ordinary ward. During intensive care, 50% of patients died and their death was associated with older age (HR 2.06, 95% CI 1.07-3.97), obesity (HR 2.23, 95% CI 1.15-4.35) and male gender (HR 1.9, 95% CI 1.02-3.57). CONCLUSIONS: We found that admission to intensive care and poor survival were associated with advanced age and higher body mass index, albeit with differences in statistical significance. Pre-existing diseases and symptoms on admission were not associated with different clinical outcomes. Interestingly, male gender was more prevalent among SARS-CoV-2 patients and was related negatively to survival, but it was not associated with more frequent admission to intensive care.

CYP26B1 and its implications in lymphangiogenesis: Literature review and study of rare variants in two families.

CYP26B1 is a member of the cytochrome P450 family and is responsible for the break-down of retinoic acid for which appropriate levels are important for normal development of the cardiovascular and lymphatic systems. In a cohort of 235 patients with lymphatic malformations, we performed genetic testing for the CYP26B1 gene. These probands had previously tested negative for known lymphedema genes. We identified two heterozygous missense CY-P26B1 variants in two patients. Our bioinformatic study suggested that alterations caused by these variants have no major effect on the overall stability of CYP26B1 protein structure. Balanced levels of retinoic acid maintained by CYP26B1 are crucial for the lymphatic system. We identified that CYP26B1 could be involved in predisposition for lymphedema. We propose that CYP26B1 be further explored as a new candidate gene for genetic testing of lymphedema patients.

Pheromone receptors and their putative ligands: possible role in humans.

Pheromones are ectohormones that play an important role in communication and behavior. Pheromones and pheromone receptor genes are important in mice and other mammals that rely heavily on pheromone cues to survive. Although there is controversy about whether pheromones and pheromone receptor genes have the same importance or are even active in humans, there are some hints that they might have roles in sociosexual behavior and mental disorders. The aim of this qualitative review was to provide an overview of the state of the art regarding pheromones and pheromone receptors in humans and their possible implications in human physiology and pathology. An electronic search was conducted in MEDLINE, PubMed and Scopus databases for articles published in English up to December 2018. The search concerned a possible role of pheromones and pheromone receptors in humans with implications for sociosexual behavior, mental disorders, the menstrual cycle and nutrition. Pheromone communication in humans has not been definitively demonstrated. However, the potential ability of putative pheromones to activate the hypothalamus, which controls the release of many hormones, suggests they could have a role in systemic functions in humans. Future confirmation of the effects of pheromones and pheromone receptors in humans could be useful in the prevention and treatment of various human disorders.

Taste, olfactory and texture related genes and food choices: implications on health status.

OBJECTIVE: The food choices are due to a mixture of sensory signals including gustatory, olfactory, and texture sensations. The aim of this quality review was to update data about studies concerning genetics of taste, olfactory and texture receptors and their influence on the health status in humans. MATERIALS AND METHODS: An electronic search was conducted in MEDLINE, Pubmed database and Scopus, for articles published in English until December 2018. Two independent researches selected the studies and extracted the data. RESULTS: The review confirms the importance of inter-individual variations in taste, olfactory and texture related genes on food choices and their implications in the susceptibility to nutrition-related conditions such as obesity, dental caries, diabetes, cardiovascular disease, hypertension, hyperlipidemia and cancer. CONCLUSIONS: The knowledge of variants in taste, olfactory and texture related genes can contribute to the prevention of diseases related to unhealthy nutrition. Further studies would be useful to identify other variants in the genes involved in these systems.