The CRISPR/Cas9 bacterial system has proven to be an powerful tool for genetic manipulation in several organisms, but the efficiency of sequence replacement by homologous direct repair (HDR) is substantially lower than random indel creation. Many studies focused on improving HDR efficiency using double sgRNA, cell synchronization cycle, and the delivery of single-stranded oligo DNA nucleotides (ssODN) with a rational design. In this study, we evaluate these three methods’ synergistic effects to improve HDR efficiency. For our tests, we have chosen the TNFα gene (NM_000594) for its crucial role in various biological processes and diseases. For the first time, our results showed how the use of two sgRNA with asymmetric donor design and triple transfection events dramatically increase the HDR efficiency from an undetectable HDR event to 39% of HDR efficiency and provide a new strategy to facilitate CRISPR/Cas9-mediated human genome editing. Besides, we demonstrated that the TNFα locus could be edited with CRISPR/Cas9 methodology, an opportunity to safely correct, in the future, the specific mutations of each patient.
19 October 2018 in European Journal of Human Genetics
CSNK2B encodes for the regulatory subunit of the casein kinase II, a serine/threonine kinase that is highly expressed in the brain and implicated in development, neuritogenesis, synaptic transmission and plasticity. De novo variants in this gene have been identified as the cause of the Poirier-Bienvenu Neurodevelopmental Syndrome (POBINDS) characterized by seizures and variably impaired intellectual development. More than sixty mutations have been described so far. However, data clarifying their functional impact and the possible pathomechanism are still scarce. Recently, a subset of CSNK2B missense variants affecting the Asp32 in the KEN box-like domain were proposed as the cause of a new intellectual disability-craniodigital syndrome (IDCS). In this study, we combined predictive functional and structural analysis and in vitro experiments to investigate the effect of two CSNK2B mutations, p.Leu39Arg and p.Met132LeufsTer110, identified by WES in two children with POBINDS. Our data prove that loss of the CK2beta protein, due to the instability of mutant CSNK2B mRNA and protein, resulting in a reduced amount of CK2 complex and affecting its kinase activity, may underlie the POBINDS phenotype. In addition, the deep reverse phenotyping of the patient carrying p.Leu39Arg, with an analysis of the available literature for individuals with either POBINDS or IDCS and a mutation in the KEN box-like motif, might suggest the existence of a continuous spectrum of CSNK2B-associated phenotypes rather than a sharp distinction between them.
Congenital clubfoot is a common pediatric malformation that affects approximately 0.1% of all births. 80% of the cases appear isolated, while 20% can be secondary or associated with complex syndromes. To date, two genes that appear to play an important role are PTIX1 and TBX4, but their actual impact is still unclear. Our study aimed to evaluate the prevalence of pathogenic variants in PITX1 and TBX4 in Italian patients with idiopathic clubfoot. PITX1 and TBX4 genes were analyzed by sequence and SNP array in 162 patients. We detected only four nucleotide variants in TBX4, predicted to be benign or likely benign. CNV analysis did not reveal duplications or deletions involving both genes and intragenic structural variants. Our data proved that the idiopathic form of congenital clubfoot was rarely associated with mutations and CNVs on PITX1 and TBX4. Although in some patients, the disease was caused by mutations in both genes; they were responsible for only a tiny minority of cases, at least in the Italian population. It was not excluded that other genes belonging to the same TBX4-PITX1 axis were involved, even if genetic complexity at the origin of clubfoot required the involvement of other factors.
Early detection of recurrences in gynecological cancers is crucial for women’s health. Circulating tumor DNA (ctDNA) analysis through liquid biopsy offers a promising approach for monitoring disease progression and identifying relapses. This study investigated the utility of digital Polymerase Chain Reaction (dPCR) for ctDNA detection in three gynecological cancer patients with clinically confirmed relapses during a two-year post-surgical follow-up. Patient-specific tumor mutations were identified through whole-exome sequencing (WES) and confirmed via Sanger sequencing. dPCR probes targeting these mutations were used to quantify the ctDNA levels in plasma samples collected throughout the follow-up period, and the findings were compared with standard serum biochemical markers. In two patients, persistent positive dPCR signals for the selected mutations were detected after tumor removal, with ctDNA levels progressively increasing even after post-surgical chemotherapy. Notably, dPCR identified elevated ctDNA levels before an increase in the cancer antigen 125 (CA125) biochemical marker was observed. In the third patient, no ctDNA signals from the two selected mutations were detected despite clinical evidence of recurrence, suggesting the emergence of new mutations. While this study highlights the promise of dPCR for early recurrence detection in gynecological cancers, it also underscores the critical need for comprehensive mutation panels to overcome the inherent challenges posed by tumor heterogeneity and the emergence of new mutations during disease progression.