Abstract in English:

Abstract Methylenetetrahydrofolate reductase (MTHFR) gene is involved in homocysteine and folic acid metabolism. Tumour suppressor protein TP53 gene maintains cellular and genetic integrity. To date, no studies associated the MTHFR C677T rs1801133 and TP53 Pro72Arg rs1042522 with CRP levels and methotrexate (a folic acid antagonist) treatment outcomes in psoriatic arthritis (PsA) patients. The present study aimed to investigate whether the MTHFR rs1801133 and TP53 rs1042522 gene variants influences CRP levels and methotrexate treatment outcomes in South African Indian and Caucasian PsA patients. PsA patients (n=114) and healthy controls (n=100) were genotyped for the rs1801133 and rs1042522 using RFLP-PCR. (i) Results for rs1801133 genotyping: Caucasian patients had a higher frequency of the variant T-allele versus healthy Caucasian controls (40% versus 22%; OR=2.31, 95% CI=1.10-4.88, p=0.0379). Patients with the variant CT+TT genotypes had higher median CRP levels at baseline versus wildtype CC genotypes (11.70 (5.3-28.80) mg/mL versus 7.40 (5.00-15.05) mg/mL, p=0.0355). After 6 months of methotrexate treatment median CRP levels between genotypes reduced and remained similar. (ii) Results for rs1042522 genotyping: Indian patients had a higher frequency of the variant Arg-allele versus healthy Indian controls (42% versus 29%; OR=1.75, 95% CI=1.07-2.86, p=0.0275). In conclusion, patients with the MTHFR rs1801133 variant T-allele have elevated CRP levels, which can be ameliorated with methotrexate.

Abstract in English:

Abstract Sperm-associated antigen 9 (SPAG9) is a member of cancer-testis antigen, having characteristics of a scaffold protein, which is involved in the c-Jun N-terminal kinase JNK signaling pathway, suggesting its key involvement in different physiological processes, such as survival, apoptosis, tumorigenesis, and cell proliferation. We identified two families (A and B) having multisystem features like coarse facial features, albinism, cataracts, skeletal abnormalities, and developmental delay. Whole genome sequencing (WGS) in families A and B revealed a homozygous frameshift variant (c.903del; p.Phe301Leufs*2) in the SPAG9 gene. Sanger sequencing of both families revealed perfect segregation of the identified variant in all family members. 3D protein modeling revealed substantial changes in the protein’s secondary structure. Furthermore, RT-qPCR revealed a substantial reduction of SPAG9 gene expression at the mRNA level in the affected individuals of both families, thus supporting the pathogenic nature of the identified variant. For the first time in the literature, biallelic SPAG9 gene variation was linked to multisystem-exhibiting features like coarse facial features, albinism, cataracts, skeletal abnormalities, and developmental delay. Thus, this data supports the notion that SPAG9 plays an important role in a multisystemic disorder in humans.

Abstract in English:

Abstract Rare heterozygous variants in IRF6 (interferon regulatory factor-6) gene cause van der Woude syndrome 1 (VWS1) or Popliteal Pterygium syndrome, two forms of syndromic cleft lip/palate (CLP) that present with a variety of congenital malformations due to impairment ectodermal homeostasis. These malformations include, in addition to CLP, lip pits, pterygia, and intraoral and eyelid fibrous bands. Amniotic band sequence (ABS) is a rare condition of unknown genetic etiology that involves a range of congenital anomalies caused by the entanglement of fibrous bands, which disrupt fetal body parts. However, ABS co-occurs with CLP and other malformations that cannot be explained by this mechanism. Therefore, investigating the genetic relationship between ABS and CLP may provide clues regardind the genes involved in these conditions. Here, we report a case of a girl diagnosed with VWS1, autism, intellectual disability, and congenital right limb anomalies compatible with ABS. Molecular analysis revealed a novel, rare heterozygous missense variant in IRF6 (NM_006147.3:c.970T>C) located in exon 7, inherited from her father. This variant results in the replacement of serine by proline at position 324 of the IRF6 protein with potentially deleterious effects. This report expands the mutational landscape of IRF6 and provides further support for a possible link between the genetics of CLP and ABS.

Abstract in English:

Abstract Tumor necrosis factor-alpha (TNF-α), is partly attributed to pathogenesis of end-stage renal disease (ESRD). Inconsistency of reported associations between TNF-α G-308A polymorphism (rs1800629) and ESRD prompted a meta-analysis to obtain more precise estimates. Eleven case-control studies from 11 articles were included. Pooled odds ratios (OR) and 95% confidence intervals (95% CIs) were estimated to evaluate the association. Subgroup analysis was based on ethnicity (Caucasian and Asian). Multiple comparisons were Bonferroni-corrected. Trial sequential analysis (TSA) was implemented to ascertain the reliability of results. Sensitivity analyses and publication bias tests were performed on significant results. There were no significant association (pa >0.05) in the overall and ethnic subgroup. Indians, three significant pool ORs (pa < 0.01-0.03) showed increased susceptibility to ESRD in homozygous (OR, 6.57; 95% CI, 1.45 to 29.75; pa = 0.01), recessive (OR, 6.75; 95% CI, 1.44 to 31.56; pa = 0.02), and codominant (OR, 2.06; 95% CI, 1.08 to 3.94; pa = 0.03) models. TSA indicated the robustness of such association in the Indian population. The main outcomes were robust without evidence of publication bias. This study showed associations between TNF-α G-308A and ESRD are confined to Indians, which are susceptible to ESRD up to approximately 7 times.

Abstract in English:

Abstract Centromochlus heckelii has the lowest diploid chromosome number (2n = 46) and the only described heteromorphic sex chromosome system in Auchenipteridae. This study presents a population of C. heckelii from the Central Amazon basin with subtle variations in the karyotype composition and a variant W chromosome with distinct morphology and increased C-positive heterochromatin content. In this population, the W chromosome is subtelocentric, whereas the only previous study on C. heckelii reported a metacentric W chromosome. Constitutive heterochromatin (CH) and accumulation of microsatellite motifs have significantly contributed to this W chromosome enlargement. Notably, this population exhibits numerous interstitial telomeric sites (ITSs). Some of these ITSs might represent genuine chromosomal fusion points due to the reduced 2n; however, additional mechanisms, such as chromosomal inversions, translocations, transpositions, or association with satellite DNA, are likely responsible for this unusual pattern. The 18S rDNA sites were found in both the Z and W chromosomes of all individuals. However, two individuals exhibited an additional 18S rDNA site in a single homologous of the chromosome pair 20, characterizing an intrapopulation polymorphism. The 5S rDNA sites were found in two chromosome pairs, distinguishing this population from other Centromochlinae species and further supporting it as one of the most efficient cytotaxonomic markers within the subfamily.

Abstract in English:

Abstract Here we analyze the Yaravirus brasiliense, an amoeba-infecting 80-nm-sized virus with a 45-kbp dsDNA, using structural molecular modeling. Almost all of its 74 genes were previously identified as ORFans. Considering its unprecedented genetic content, we analyzed Yaravirus genome to understand its genetic organization, its proteome, and how it interacts with its host. We reported possible functions for all Yaravirus proteins. Our results suggest the first ever report of a fragment proteome, in which the proteins are separated in modules and joined together at a protein level. Given the structural resemblance between some Yaravirus proteins and proteins related to tricarboxylic acid cycle (TCA), glyoxylate cycle, and the respiratory complexes, our work also allows us to hypothesize that these viral proteins could be modulating cell metabolism by upregulation. The presence of these TCA cycle-related enzymes specifically could be trying to overcome the cycle’s control points, since they are strategic proteins that maintain malate and oxaloacetate levels. Therefore, we propose that Yaravirus proteins are redirecting energy and resources towards viral production, and avoiding TCA cycle control points, “unlocking” the cycle. Altogether, our data helped understand a previously almost completely unknown virus, and a little bit more of the incredible diversity of viruses.