SARS-CoV-2 infection activating a novel variant of the NOTCH3 gene and subsequently causing development of CADASIL.

Introduction: In the following study we describe the diagnostic process and further case analysis of a 30-year-old woman admitted with typical COVID-19 symptoms, who subsequently developed additional symptoms suggesting cerebral autosomal dominant arteriopathy with sub-cortical infarcts and leukoencephalopathy (CADASIL). Material and methods: Other than the standard diagnostic procedures, whole genome sequencing (WGS) was used, which led to following findings. A new variant of the NOTCH3 gene, which led to CADASIL-like symptoms, was found, and it had been most likely activated by the SARS-CoV-2 infection. This novel variant in NOTCH3 has not been found in existing databases and has never been mentioned in research concerning CADASIL before. Results: Furthermore, after subjecting the patient's close relatives to WGS it was found that no other examined person demonstrated the same genetic mutation. Conclusions: It seems therefore that the new variant of NOTCH3 is of de novo origin in the patient's genome. Additionally, the relatively early onset of CADASIL and the unexpectedly severe COVID-19 infection suggest that the two occurred simultaneously: the infection with SARS-CoV-2 accelerated development of CADASIL symptoms and the unusual variant of the NOTCH3 gene contributed to the more severe course of COVID-19.

Gene Variants Related to Cardiovascular and Pulmonary Diseases May Correlate with Severe Outcome of COVID-19.

Background: Severe outcomes of COVID-19 account for up to 15% of all cases. The study aims to check if any gene variants related to cardiovascular (CVD) and pulmonary diseases (PD) are correlated with a severe outcome of COVID-19 in a Polish cohort of COVID-19 patients. Methods: In this study, a subset of 747 samples from unrelated individuals collected across Poland in 2020 and 2021 was used and whole-genome sequencing was performed. Results: The GWAS analysis of SNPs and short indels located in genes related to CVD identified one variant significant in COVID-19 severe outcome in the HADHA gene, while for the PD gene panel, we found two significant variants in the DRC1 gene. In this study, both potentially protective and risk variants were identified, of which variants in the HADHA gene deserve the most attention. Conclusions: This is the first study reporting the association between the HADHA and DRC1 genetic variants and COVID-19 severe outcome based on the cohort WGS analysis. Although all the identified variants are localised in introns, they may be correlated and therefore inherited along with other risk variants, potentially causative to severe outcome of COVID-19 but not discovered yet.

The Thousand Polish Genomes-A Database of Polish Variant Allele Frequencies.

Although Slavic populations account for over 4.5% of world inhabitants, no centralised, open-source reference database of genetic variation of any Slavic population exists to date. Such data are crucial for clinical genetics, biomedical research, as well as archeological and historical studies. The Polish population, which is homogenous and sedentary in its nature but influenced by many migrations of the past, is unique and could serve as a genetic reference for the Slavic nations. In this study, we analysed whole genomes of 1222 Poles to identify and genotype a wide spectrum of genomic variation, such as small and structural variants, runs of homozygosity, mitochondrial haplogroups, and de novo variants. Common variant analyses showed that the Polish cohort is highly homogenous and shares ancestry with other European populations. In rare variant analyses, we identified 32 autosomal-recessive genes with significantly different frequencies of pathogenic alleles in the Polish population as compared to the non-Finish Europeans, including C2, TGM5, NUP93, C19orf12, and PROP1. The allele frequencies for small and structural variants, calculated for 1076 unrelated individuals, are released publicly as The Thousand Polish Genomes database, and will contribute to the worldwide genomic resources available to researchers and clinicians.