Donor Genotype Research Articles

Effect of NK cell receptor genetic variation on allogeneic stem cell transplantation outcome and in vitro NK cell cytotoxicity

Natural killer (NK) cells recognize and may kill malignant cells via their cell surface receptors. Killer cell immunoglobulin-like receptor (KIR) genotypes of donors have been reported to adjust the risk of relapse after allogeneic stem cell transplantation (HSCT), particularly in patients with acute myeloid leukemia. To test whether non-KIR NK cell receptors have a similar effect, we screened 1,638 genetic polymorphisms in 21 non-KIR NK cell receptor genes for their associations with relapse and graft-versus-host disease (GVHD) after HSCT in 1,491 HSCT donors (from Finland, the UK, Spain, and Poland), divided into a discovery and replication cohort. Eleven polymorphisms regulating or located in CD226, CD244, FCGR3A, KLRD1, NCR3, and PVRIG were associated with the risks for relapse and GVHD. These associations could not be confirmed in the replication cohort. Blood donor NK cells carrying alleles showing genetic protection for relapse had a higher in vitro NK cell killing activity than non-carriers whereas those with alleles genetically protective for GVHD had lower cytotoxicity, potentially indicating functional effects. Taken together, these results show no robust effects of genetic variation in the tested non-KIR NK cell receptors on the outcome of HSCT.

Influence of recipient KRAS gene rs712 polymorphisms on the overall survival rate of hepatocellular carcinoma after hepatic transplantation

Hepatocellular carcinoma (HCC) recurrence appears commonly after liver transplantation (LT), and it severely affected the long-term survival of patients. Previous studies have proved that Rap1A is involved in hepatocarcinogenesis and metastasis, and demonstrated the significant association between KRAS rs712 polymorphism and HCC. However, the relationship between KRAS rs712 polymorphism and HCC recurrence after LT remained unclear. A total of 93 HCC patients who underwent LT from March 2008 to Dec 2015 was analyzed. The genotypes of both donors and recipients had been confirmed as KRAS rs712. The independent risk factors that associated with HCC recurrence were investigated with univariate and multivariate logistic regression analysis. The recurrence-free (RFS) and overall survival (OS) were calculated with Cox regression analysis. The KRAS rs712 genotype frequencies were determined using the Χ2 test and the minor allele frequencies (MAFs) of KRAS rs712 genotypes were calculated by Hardy–Weinberg equilibrium. We found that the recipient KRAS rs712 polymorphism was significantly associated with HCC recurrence after LT. Moreover, the Milan criteria, microvascular invasion and recipient KRAS rs712 genotype were proved to be independent risk factors for HCC recurrence after LT. Patients with donor TG/TT genotypes had a significantly higher RFS and OS than TT genotype. The TNM stage, microvascular invasion, Milan criteria, treatment and recipient KRAS rs712 genotype were independent factors for the RFS of LT patients. Recipient KRAS rs712 polymorphism is associated with HCC recurrence after liver transplantation and plays as a promising bio-predictor of overall survival rate of HCC risks after hepatic transplantation.

B-222 Receptor-donor CYP3A5 and CYP3A4 genotype testing in liver transplant patients and its influence in tacrolimus blood levels: a retrospective study

Abstract Background Optimal immunosupression is crucial for transplant success. In orthohepatic transplants, blood target levels of tacrolimus, when coadministred with corticoids and mycophenolic acid, are between 6 and 10 ng/mL during the first three months post-transplant. Notwithstanding, achieving tacrolimus concentrations into this range may be tough because of factors such as liver function status, age, sex, drug-drug interactions, etc. In this way, pharmacogenetic testing of CYP3A5 and CYP3A4 genes have demonstrated to be useful in tacrolimus dosing optimization. Nonetheless, there is no evidence enough for pharmacogenetic based adjusting in liver transplant, specially if receptor and graft’s genotypes differ in these loci. The aim of the present study is to find out how the receptor and donor genotypes in CYP3A5 and CYP3A4 genes affect tacrolimus pharmacokinetics. Methods Genotypic profiling of 108 receptor-donor's pairs biopsies gathered from patients who were underwent hepatic transplant from 2012 to 2019 were carried out using Taqman® OpenArray™ PGx Express 120 panel (ThermoFisher™). We focused on CYP3A5*3, *6 and *7; and CYP3A4*1B, *3 and *22 alleles. Next to pharmacogenetic testing, each patient was classified as very poor, poor, intermediate, rapid or ultrarapid metabolizer according to their own genotype, graft’s genotype or both of them. Patient’s initial dose, at seven days after treatment start and after discharge of tacrolimus and their trough concentrations (C0) were collected from their electronic health records. Tacrolimus levels were measured by affinity chrome-mediated immunoassay. C0 was normalized by weight-adjusted dosage (C/D ratio); then, median C/D ratios between different metabolic profiles were compared through Kruskal-Wallis test. Results When patients were classified based on donor’s genotype isolated or combined with receptor’s genotype, lower C/D ratios were found as metabolizer ability increases (p=0.045 for donors and p=0.027 for combined genotypes, respectively). No statistically differences were found for C/D ratios at seven days and discharge, though that differences were almost significant for donor’s genotypes (p=0.06 in both cases). Conclusions These results show that previous information about both patient’s and specially donor’s CYP genes genotype may improve initial immunosupression and avoid tacrolimus induced toxicity. Pharmacogenetics has been currently proposed as a guide for tacrolimus treatment of some solid organ transplants as kidney transplanted patients. Better understanding of how receptor and donor’s CYP genotype affects its pharmacokinetics, along with liver’s damage markers and other genetic polymorphisms will allow clinicians, in the era of personalized medicine, to improve immunosupressive management.

HLA Diversity in Transylvanian Ethnic Groups: Consequences for Hematopoietic Cell Transplantation

The HLA profile is essential in cell and tissue transplantation, particularly in patients with autoimmune conditions and infections. Due to the extreme polymorphism in certain HLA loci, it also serves as a key tool for population genetic analysis. This study aimed to identify the allele and haplotype distributions of HLA class I (A, B, and C) and class II (DRB1) genotypes in unrelated hematopoietic stem cell donors. A retrospective analysis was conducted between 2016 and 2020 on 9832 Transylvanian volunteers, divided into Romanian and Hungarian groups based on self-reported ethnicity. Using PCR-SSO for HLA typing, significant differences were found in allele frequencies between ethnic groups. A total of 19 HLA-A, 31 HLA-B, 14 HLA-C, and 13 HLA-DRB1 distinct allele groups were identified between ethnic groups. Notably, B*18, B*51, and C*12 were more frequent in Romanians, while B*44, B*40, and C*07 were more common in Hungarians. Differences in haplotype distributions were also observed, with HLA-A*02~B*18~C*07~DRB1*11 being significantly more frequent in Romanians. Understanding these population-specific HLA profiles can improve donor matching for hematologic diseases, enhancing patient outcomes and access to life-saving hematopoietic stem cell transplantation.

Curation of historical phenotypic wheat data from the Czech Genebank for research and breeding

Climate change and population growth are putting increasing pressure on global food security. The development of high-yielding varieties for important crops such as wheat is crucial to meet these challenges. The basis for this is extensive exploitation of beneficial genetic variation resting in genebanks around the world. Selecting suitable donor genotypes from the vast number of wheat accessions stored in genebanks is a difficult task and depends critically on the density of information on the performance of individual accessions. Therefore, this study aimed to access phenotypic data from the Czech genebank, storing over 13,000 wheat accessions. We curated and analyzed data on heading date, plant height, and thousand grain weight for more than one-third of all available accessions regenerated across 70 years. The data underwent analysis using a linear mixed model, revealing high quality of curated data with heritability reaching 99%. The raw data, but also derived data such as the best linear unbiased estimations, are now available for the wheat collection of the Czech genebank for research and breeding.

HIV Subtypes and Drug-resistance-associated Mutations in US Blood Donors, 2015-2020.

Monitoring genotypes of HIV infections in blood donors may provide insights into infection trends in the general population. HIV RNA was extracted from plasma samples of blood donors confirmed as HIV positive by blood screening nucleic acid and antibody tests. HIV genome target regions were amplified using nested real time-polymerase chain reaction followed by next-generation sequencing. Sequences were compared to those in the Los Alamos National Laboratory (LANL) database. Sequences were also assessed for drug resistance mutations (DRM) using the Stanford HIV DRM Database. From available HIV-positive donations collected between 1 September 2015 and 31 December 2020, 563 of 743 (75.8%) were successfully sequenced; 4 were subtype A, 543 subtype B, 5 subtype C, 1 subtype G, 5 circulating recombinant forms (CRF), and 2 were subtype B and D recombinants. Overall, no significant differences between blood donor and available LANL genotypes were found, and the genotypes of newly acquired versus prevalent HIV infections in donors were similar. The proportion of non-B subtypes and CRF remained a small fraction, with no other subtype or CRF representing more than 1% of the total. DRM were identified in 122 (21.6%) samples with protease inhibitor, nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitor DRMs identified in 4.9%, 4.6% and 14.0% of samples, respectively. HIV genetic diversity and DRM in blood donors appear representative of circulating HIV infections in the US general population and may provide more information on infection diversity than sequences reported to LANL, particularly for recently transmitted infections.

Highly Defined Induced Pluripotent Stem Cell Lines Mimic Donor Red Blood Cell Antigen Profiles for Therapeutic and Diagnostic Use.

Our group generated two induced pluripotent stem cell (iPSC) lines for in vitro red blood cell (RBC) production from blood donors with extensively known erythrocyte antigen profiles. One line was intended to give rise to RBCs for transfusions in patients with sickle cell disease (SCD), while the other was developed to create RBC panel reagents. Two blood donors were selected based on their RBC phenotypes, further complemented by high-throughput DNA array analysis to obtain a more comprehensive erythrocyte antigen profile. Enriched erythroblast populations from the donors' peripheral blood mononuclear cells were reprogrammed into iPSCs using nonintegrative plasmid vectors. The iPSC lines were characterized and subsequently subjected to hematopoietic differentiation. iPSC PB02 and iPSC PB12 demonstrated in vitro and invivo iPSC features and retained the genotype of each blood donor's RBC antigen profile. Colony-forming cell assays confirmed that iPSC PB02 and iPSC PB12 generated hematopoietic progenitors. These two iPSC lines were generated with defined erythrocyte antigen profiles, self-renewal capacity, and hematopoietic differentiation potential. With improvements in hematopoietic differentiation, these cells could potentially be more efficiently differentiated into RBCs in the future. They could serve as a complementary approach for obtaining donor-independent RBCs and addressing specific demands for blood transfusions.

Rh D-positive genotypes in Brazilian blood donors with D-negative phenotype

Rh D-positive genotypes in Brazilian blood donors with D-negative phenotype

Introgression of the Self-Pruning Gene into Dwarf Tomatoes to Obtain Salad-Type Determinate Growth Lines.

The use of dwarf plants in tomato breeding has provided several advantages. However, there are no identified dwarf plants (dd) containing the self-pruning habit (spsp). The aim of this work was to obtain future generations, characterize the germplasm, and select potential dwarf plants with a determinate growth habit to obtain Salad-type lines. The work was started by carrying out hybridization, followed by the first, second, and third backcrosses. Once F2BC3 seeds became available, the introgression of the self-pruning gene (spsp) into dwarf plants (dd) began. Three strains of normal architecture and a determinate growth habit were hybridized with two strains of dwarf size and an indeterminate growth habit, thus yielding four hybrids. Additionally, donor genotype UFU MC TOM1, the commercial cultivar Santa Clara, and the wild accession Solanum pennellii were used in the experiment. Agronomic traits, fruit quality, metabolomics, and acylsugars content were evaluated, and dwarf plants with a determinate growth habit were selected. Hybrid 3 exhibited the highest yields. Visual differences between determinate and indeterminate dwarf plant seedlings were observed. It is suggested to carry out five self-pollinations of the best dwarf plant determined and subsequent hybridization with homozygous lines of normal plant architecture and determinate growth habit to obtain hybrids.

#2461 KIR-HLA-I genetic mismatch and the development of antibody-mediated rejection and microvascular inflammation after renal transplantation

Abstract Background and Aims Antibody-mediated rejection (ABMR) and microvascular inflammation (MVI) contribute to kidney transplant (KT) loss of function. The contribution of Natural Killer (NK) cells to the development of ABMR/MVI through inhibitory (iKIR) and activating (aKIR) HLA-I KIR (Killer-cell Immunoglobulin-like Receptors) has been proposed. The presence of an iKIR gene in the KT recipient (KTR) recognizing a self HLA-I ligand absent in the donor is defined as an iKIR-HLA-I mismatch (MM), and the presence of an aKIR gene in the KTR with HLA-I ligand in the graft absent in the KTR is defined as an aKIR-HLA-I MM. These MMs indicate the presence of potentially alloreactive NK cells that could contribute to the graft rejection, especially in the presence of NK receptor activating ligands or DSA. Our aim was to study the relationship between the number of KIR-HLA-I mismatches and ABMR/MVI. Method We selected 56 first KT, not treated with thymoglobulin or rituximab: 24 cases with ABMR/MVI and 32 controls without rejection in biopsies at 12-36 months. Donor and recipient HLA-I genotypes were determined by NGS, and recipient KIR genotypes by PCR-SSO (Luminex). The interactions considered were: KIR2DL1/HLA-C2, KIR2DL2&KIR2DL3/HLA-C1, KIR3DL1/HLA-Bw4, KIR3DL2/HLA-A*03, A*11, KIR2DS1/HLA-C2, KIR2DS2/HLA-C1, KIR3DS1/HLA-Bw4-I80 and KIR2DS4/HLA-A*11, C*02, C*04, C*05, C*16:01. Results KT recipients had a mean age of 54.55 years, 30.36% female and 8.92% living donor with no significant differences between ABMR/MVI and controls. The proportion of patients with ≥1 iKIR-HLA-I MM was higher in the ABMR/MVI group compared to controls (75% vs 56.25%, P = .1473), with a significant difference in the percentage of KIR3DL1 MM (29.17% vs 6.25%, P = .0296). The proportion of patients with at least one aKIR-HLA-I MM was non-significantly lower in ABMR/MVI compared to the control group (20.83% vs 28.13%, P = .5329). Overall, the proportion of KT recipients with ≥1 MM, either iKIR or aKIR, was 21% higher in the ABMR/MVI group (83.33% vs 68.75%, P = .2123). Conclusion In a population of immunologically low-risk KT recipients, we found a significantly greater proportion of patients with genetic iKIR-HLA-I MM in those with ABMR/MVI, but not of aKIR-HLA-I MM. NK cells with iKIR-HLA-I MM could contribute to antibody-mediated allograft damage together with other mechanisms.

Mutations in the dwarf3 gene confer height stability in sorghum.

Dwarfism is a useful trait in many crop plants because it contributes to improved lodging resistance and harvest index. The mutant allele dw3-ref (dwarf3-reference) of sorghum [Sorghum bicolor (L.) Moench] is characterized by an 882bp tandem duplication in the fifth exon of the gene that is unstable and reverts to wild-type at a frequency greater than 0.001 in many genetic backgrounds. The goal of this research was to identify stable alleles of dw3 (dwarf3) that could be backcrossed into elite parent lines to improve height stability of the crop. To discover new alleles of dw3, a panel consisting mostly of sorghum conversion lines (SC-lines) was screened by polymerase chain reaction for the 882bp tandem duplication in the fifth exon of dw3-ref. Sanger sequencing was used to characterize the DNA sequence of this fragment in genotypes that did not contain the 882bp tandem duplication. Sequence analysis identified three indel mutations, including an 82bp deletion, a 6bp duplication, and a 15bp deletion in this region of the gene. Field trials of the donor genotypes with these new alleles indicated no wild-type revertants of dw3-sd3 (dwarf3-stable dwarf), dw3-sd4, and dw3-sd5. These alleles were backcrossed into Tx430. Field trials of backcross progeny (BC2F4) with the dw3-sd3, dw3-sd4, and dw3-sd5 alleles indicated no revertants. The plant height and flowering time characteristics of the backcross progeny were similar or slightly shorter and earlier than the recurrent parent. These findings demonstrate that dw3-sd3, dw3-sd4, and dw3-sd5 alleles will be useful in breeding for the stable dwarf trait.

Impact of donor CYP3A5 genotype on pharmacokinetics of tacrolimus in South African paediatric liver transplant patients.

In the paediatric liver transplant programme in Johannesburg, South Africa (SA), tacrolimus is the calcineurin inhibitor of choice, comprising an essential component of the immunosuppression regimen. It is characterised by a narrow therapeutic index and wide interpatient variability, necessitating therapeutic drug monitoring of whole-blood concentrations. Pharmacogenetic research, although not representative of SA population groups, suggests that single-nucleotide polymorphisms within the cytochrome P450 3A5 (CYP3A5) gene contribute to the variability in tacrolimus dosing requirements. The rs776746 polymorphism, CYP3A5*3, results in a splice defect and a non-functional enzyme. Clinically, to reach the same tacrolimus concentration-to-dose ratio (CDR), expressors (CYP3A5*1/*1 and *1/*3) require a higher tacrolimus dose than non-expressors (*3/*3). To compare the pharmacokinetics of tacrolimus in paediatric liver transplant recipients with their donors' CYP3A5 genotypes, considering both donor and recipient characteristics. Blood samples from 46 living liver donors were collected, their genomic DNA was extracted, and their CYP3A5 genotype was established (polymerase chain reaction and restriction fragment length polymorphism analysis, validated by Sanger sequencing). The relationship of donor and recipient characteristics with the mean tacrolimus CDR was analysed using a general linear model. Non- confounding significant variables were included in a multiple regression model. The study showed that all expressor donors genotyped as CYP3A5*1/*1 were of black African self-reported race and ethnicity. During the first 15 days post-transplant, we found that children who received grafts from donor CYP3A5 expressors (CYP3A5*1/*1 and *1/*3) had significantly lower mean tacrolimus CDRs compared with those who received grafts from donor CYP3A5 non-expressors (*3/*3); the recipients of CYP3A5 expressor grafts therefore require higher doses of oral tacrolimus to achieve the same therapeutic target range. In addition, graft-to-recipient weight ratio and the CYP3A5 donor genotypes were independent factors that significantly (p<0.05) affected mean tacrolimus CDRs in recipients. In this study, we showed that all CYP3A5*1 homozygote donors were of black African self-reported race and ethnicity, and tacrolimus CDRs in paediatric living-donor liver transplant recipients were significantly affected by donor graft size and donor CYP3A5 genotypes. Information from this study may inform the development of an Afrocentric tacrolimus precision-medicine algorithm to optimise recipient safety and graft outcomes.

Organogenesis of Plant Tissues in Colchicine Allows Selecting in Field Trial Blueberry (Vaccinium spp. cv Duke) Clones with Commercial Potential

Plants’ genetic improvement continues to be crucial for modern agriculture, while biotechnology can offer efficient tools that enhance the selection and recommendation processes of elite clones. This work established a suitable methodology for the regeneration of blueberry (Vaccinium corymbsum) plants in cultures with colchicine. This could be considered a basis for producing populations for the selection of clones following a genetic improvement program assisted by biotechnology. The factors studied were: (a) explant type (leaf discs; nodal segments); (b) colchicine concentration (0, 0.5, 1, and 2 mg/L); and (c) time of exposure to colchicine (1, 2, 3, 5, and 30 days). The basal medium McCown’s Woody Plant (WP) supplemented with 2 mg/L 2iP and 1 mg/L BAP was used with the commercial genotype Duke as a model. A total of 1957 blueberry clones were produced in a medium with 1 mg/L colchicine, distributed at different exposure times. Flow cytometry analyses revealed the following patterns: single patterns for random samples of control plants (Duke donor) and some clones regenerated on colchicine; double patterns for chlorotic plants regenerated on colchicine. Triple and quadruple patterns were observed in callus tissues that did not regenerate plants on colchicine. Populations of plants regenerated in colchicine (6787) and control plants regenerated in in vitro culture without colchicine were adapted under greenhouse conditions. The variables evaluated at this stage were adaptability, height, diameter, number of leaves, incidence of diseases, flowering capacity, and agrobotanical traits. Selected clones demonstrating phenotypic variability (157 clones) were transplanted to field conditions. From the clonal field trial conducted under minimum tillage conditions, 38 clones were selected for improved traits related to the agricultural yield and nutritional quality of the fruits. Of these, six clones showed the highest agronomic performance and adaptability to adverse environmental conditions compared to the Duke donor genotype. It is recommended that these clones continue genotype × environment interaction trials at different locations.

Recoding the gift relationship: views on introducing genomic testing to blood donation

This study examines how the institutional context informs the ways in which healthy recipients relate to genomic information. Through focus group data, it considers the trend of blood collection agencies (BCA) moving to extend donor genotyping. We investigated how receipt of genomic information is viewed as fitting into the contract of altruistic, voluntary blood donation by donors and non-donors. Our findings suggest that receipt of genomic health information is viewed as fitting the principles of this exchange with some limits. Participants considered the practical value of receiving different kinds of genetic information for individual and collective health from the perspectives of a healthy, altruistic donor, an “entrepreneurial self” and a potential patient. Findings identify the importance of considering the ethics of providing information on genomic markers to blood donors without current clinical value, as well as the impact of providing this information on the donor – BCA relationship.

Diallel analysis of common bean (Phaseolus vulgaris L.) genotypes for seed dietary fibre, carbohydrate, calcium and phosphorus contents

Genetic information of bean seed traits can be an immense help to the breeder in selection of suitable genotypes and the appropriate breeding strategies. Therefore, the investigation aims to assess the genetic variability and to elucidate the genetic analysis of seed dietary fibre, carbohydrate, seed calcium and phosphorus contents of Phaseolus vulgaris in the high Guinean Savannah zone conditions. 5 × 5 half-diallel crosses of these traits were conducted in randomized complete block design with three replications. Results revealed high differences between five lines beans (p < 0.05), suggesting the sufficient genetic diversity for these traits. High broad sense heritability values were recorded for seed dietary fibre, carbohydrate and seed calcium content, attesting a strong implication of the genetic factors in the control of these traits; thereby, these traits can be improved through regular selection. The ratio GCA/SCA was greater than unity only for seed phosphorus content. It indicates the prevalence of additive gene effect in the involvement of the genetic control for this trait. The combining ability analysis revealed highly significant differences between parental GCA effects and F1 cross SCA effects. The PB, BI, CT and PR lines beans will prove useful in common bean breeding programmes as donor genotypes, in the development of bean genetic resources for betterment improvement of nutritional traits.

Resolving Genotype-Phenotype Discrepancies of the Kidd Blood Group System Using Long-Read Nanopore Sequencing.

Due to substantial improvements in read accuracy, third-generation long-read sequencing holds great potential in blood group diagnostics, particularly in cases where traditional genotyping or sequencing techniques, primarily targeting exons, fail to explain serological phenotypes. In this study, we employed Oxford Nanopore sequencing to resolve all genotype-phenotype discrepancies in the Kidd blood group system (JK, encoded by SLC14A1) observed over seven years of routine high-throughput donor genotyping using a mass spectrometry-based platform at the Blood Transfusion Service, Zurich. Discrepant results from standard serological typing and donor genotyping were confirmed using commercial PCR-SSP kits. To resolve discrepancies, we amplified the entire coding region of SLC14A1 (~24 kb, exons 3 to 10) in two overlapping long-range PCRs in all samples. Amplicons were barcoded and sequenced on a MinION flow cell. Sanger sequencing and bridge-PCRs were used to confirm findings. Among 11,972 donors with both serological and genotype data available for the Kidd system, we identified 10 cases with unexplained conflicting results. Five were linked to known weak and null alleles caused by variants not included in the routine donor genotyping. In two cases, we identified novel null alleles on the JK*01 (Gly40Asp; c.119G>A) and JK*02 (Gly242Glu; c.725G>A) haplotypes, respectively. Remarkably, the remaining three cases were associated with a yet unknown deletion of ~5 kb spanning exons 9-10 of the JK*01 allele, which other molecular methods had failed to detect. Overall, nanopore sequencing demonstrated reliable and accurate performance for detecting both single-nucleotide and structural variants. It possesses the potential to become a robust tool in the molecular diagnostic portfolio, particularly for addressing challenging structural variants such as hybrid genes, deletions and duplications.

Genomic prediction reveals unexplored variation in grain protein and lysine content across a vast winter wheat genebank collection.

Globally, wheat (Triticum aestivum L.) is a major source of proteins in human nutrition despite its unbalanced amino acid composition. The low lysine content in the protein fraction of wheat can lead to protein-energy-malnutrition prominently in developing countries. A promising strategy to overcome this problem is to breed varieties which combine high protein content with high lysine content. Nevertheless, this requires the incorporation of yet undefined donor genotypes into pre-breeding programs. Genebank collections are suspected to harbor the needed genetic diversity. In the 1970s, a large-scale screening of protein traits was conducted for the wheat genebank collection in Gatersleben; however, this data has been poorly mined so far. In the present study, a large historical dataset on protein content and lysine content of 4,971 accessions was curated, strictly corrected for outliers as well as for unreplicated data and consolidated as the corresponding adjusted entry means. Four genomic prediction approaches were compared based on the ability to accurately predict the traits of interest. High-quality phenotypic data of 558 accessions was leveraged by engaging the best performing prediction model, namely EG-BLUP. Finally, this publication incorporates predicted phenotypes of 7,651 accessions of the winter wheat collection. Five accessions were proposed as donor genotypes due to the combination of outstanding high protein content as well as lysine content. Further investigation of the passport data suggested an association of the adjusted lysine content with the elevation of the collecting site. This publicly available information can facilitate future pre-breeding activities.

A comprehensive study of rare Rhesus phenotype case

Introduction. The RH system includes major antigens D, C/c and E/e encoded by two closely related RHD and RHCE genes. Correct identifi cation of Rh antigens in both donors and recipients is the key to proper transfusion practice. However, there are cases when Rh antigens cannot be detected by standard serological typing. For example, –D– phenotype has no expression of C, c, E, and e antigens on the surface of erythrocytes due to various genetic rearrangements in the RHCE gene.Aim: to present a study of a family where two siblings have a defi cient -D-phenotype with a normal rhesus phenotype in the parentsMaterials and methods. A comprehensive study of family N., including parents and two sons was conducted. Initially, an unusual phenotype -D- was identifi ed in the siblings, who are currently donors. All family members identifi ed themselves as Tatars. Serology tests were performed using gel cards. Genomic DNA of family members, as well as cDNA of siblings, was examined by allele-specifi c PCR, exon-scanning assay, and Sanger sequencing. In addition, copy number analysis was performed to identify rearrangements in the RHD and RHCE genes.Results. During serological typing of siblings, only the D antigen was revealed, while the C/c and E/e antigens were absent. Molecular genetic analysis suggested that the cause of the phenotype –D– in the brothers was a hybrid allele RHCE-D(3-8)- CE in homozygous status, forming a haplotype inherited from each parent with the normal RHD allele. The sequence of the fi rst two exons in the hybrid allele corresponded to RHCE*C allele. The parents were heterozygous for the identifi ed allele, so the expression of C/c and E/e antigens was not altered.Conclusion. Two donors with the –D– phenotype were assessed by comprehensive study. Identifi cation of the genetic causes of such variants in recipients is necessary to ensure safety during transfusion of erythrocyte-containing blood components. Genotyping of donors with Rh-defi cient phenotypes is also highly recommended in order to predict the molecular structure of Rh antigens.

Effect of donor HSD17B13 genotype on patient survival after liver transplant: a retrospective cohort study

Several genetic variants are associated with chronic liver disease. The role of these variants in outcomes after liver transplantation (LT) is uncertain. The aim of this study was to determine if donor genotype at risk-associated variants in PNPLA3 (rs738409 C>G, p.I148M) and HSD17B13 (rs72613567 T>TA; rs80182459, p.A192Lfs∗8) influences post-LT survival. In this retrospective cohort study, data on 2346 adults who underwent first-time LT between January 1, 1999 and June 30, 2020 and who had donor DNA samples available at five large Transplant Immunology Laboratories in Texas, USA, were obtained from the United Network for Organ Sharing (UNOS). Duplicates, patients with insufficient donor DNA for genotyping, those who were <18 years of age at the time of transplant, had had a previous transplant or had missing genotype data were excluded. The primary outcomes were patient and graft survival after LT. The association between donor genotype and post-LT survival was examined using Kaplan-Meier method and multivariable-adjusted Cox proportional hazards models. Median age of LT recipients was 57 [interquartile range (IQR), 50-62] years; 837 (35.7%) were women; 1362 (58.1%) White, 713 (30.4%) Hispanic, 182 (7.8%) Black/African-American. Median follow-up time was 3.95 years. Post-LT survival was not affected by donor PNPLA3 genotype but was significantly reduced among recipients of livers with two HSD17B13 loss-of-function (LoF) variants compared to those receiving livers with no HSD17B13 LoF alleles (unadjusted one-year survival: 82.6% vs 93.9%, P<0.0001; five-year survival: 73.1% vs 82.9%, P=0.0017; adjusted hazard ratio [HR], 2.25; 95% CI, 1.61-3.15 after adjustment for recipient age, sex, and self-reported ethnicity). Excess mortality was restricted to those receiving steroid induction immunosuppression (crude 90-day post-LT mortality, 9.3% [95% CI, 1.9%-16.1%] vs 1.9% [95% CI, 0.9%-2.9%] in recipients of livers with two vs no HSD17B13 LoF alleles, P=0.0012; age, sex, and ethnicity-adjusted HR, 2.85; 95% CI, 1.72-4.71, P<0.0001). No reduction was seen among patients who did not receive steroid induction (90-day mortality 3.1% [95% CI, 0%-7.3%] vs 2% [95% CI, 0.9%-3.1%], P=0.65; adjusted HR, 1.17; 95% CI, 0.66-2.08, P=0.60). Donor HSD17B13 genotype adversely affects post-LT survival in patients receiving steroid induction. Additional studies are required to confirm this association. The National Institutes of Health and American Society of Transplant Surgeons Collaborative Scientist Grant.

Red Cell Rheology and Blood Viscosity in Pediatric Individuals Having Received Allogenic Hematopoietic Stem Cell Transplantation or Ex Vivo Autologous Gene Therapy for Sickle Cell Disease

Background: Allogenic hematopoietic stem cell transplantation (HCT) and ex vivo autologous gene therapies (GT) are potentially curative treatments for sickle cell disease (SCD). However, there is debate around how to define cure including what degree of donor chimerism or level of functional hemoglobin constitutes a cure. Information on red cell function post-HCT/GT and how it relates to donor chimerism and resolution of SCD complications is scarce. Red cell function tests are not currently part of follow-up care post-HCT but may provide helpful information on the degree of red cell correction and risk of SCD complications. To address this knowledge gap, we report rheology and whole blood viscosity data on HbSS patients post-HCT or GT. Methods: Blood samples were collected under an IRB-approved protocol at Baylor College of Medicine and Emory University School of Medicine. We analyzed elongation index maximum and minimum (EImax, EImin), point of sickling (PoS), hematocrit-viscosity ratio at shear rates of 45 and 225 s-1(HVR45 &amp; HVR225), and dense red blood cell % (DRBC%). EImax, EImin, and PoS were measured using a Laser Optical Rotational Red Cell Analyzer (Lorrca, RR Mechatronics, The Netherlands). Chimerism was measured by short tandem repeat testing (STR) after cell density sorting and DRBC% was measured on ADVIA cell counter (Siemens, Germany). HCT patients were compared with controls matched to the donor's genotype, and patients post-GT were compared with HbAS controls (HCT: HbAA donor =8, HbAS donor=19, GT=2, HbAA controls=42, and HbAS controls=15). Stata 18.0 (College Station, Texas, USA) was used to perform statistical analyses. Median values and ranges were used to describe the data. Wilcoxon rank sum test was used to compare groups and a mixed model was for the longitudinal data. A p-value &amp;lt;0.05 was considered statistically significant. Results: There were 29 patients with a median age of 6.6 years (range: 2.0-16.3) at HCT/GT and a median follow-up of 2.4 years (range: 0.1-7). A total of forty-three samples were analyzed. Median donor myeloid chimerism was 94% (33-100). Overall, the HbS% ranged from 28.9 - 45.2% with HbAS donors and 0% with HbAA donors. Two HbAS HCT patients had myeloid chimerism ≤ 50% with a follow-up period of 3.3 and 1.9 years, respectively. The myeloid donor% and HbS% were 33% and 50%, and 45.2% and 41.6%, respectively. At the first post-HCT/GT time-point (median 1 year, range: 0.1-6.9), DRBC%, EImax, and EImin were lower in HbAA donor HCT patients compared to HbAA controls (0.593 vs 0.604, p=0.008; 0.581 vs 0.604, &amp;lt;0.001; and 0.75 vs 0.20, p=0.02, respectively). RBC function improved with a longer follow-up from HCT/GT (median 2.9 years, range 1.3-7) with EImax showing a trend of statistical significance (p=0.07). Patients with HbAS donors had significantly higher point of sickling (PoS) values compared to the patients with HbAA donors (p=0.02). There was a trend for a lower HVR225 in patients with HbAS donors compared to the patients with HbAA donors (p=0.08). Seven patients (24%) had one or more red cell function test values outside the genotype-matched control range despite having myeloid donor chimerism of &amp;gt; 25-30% - a value commonly used in clinical practice to define cure (Table &amp; Figure). Conclusion: A substantial number of patients had abnormal red cell function tests following HCT/GT despite achieving donor engraftment. Donor myeloid chimerism ≥ 25% has been reported protective from SCD complications while a chimerism ≥50% normalized tests for hemolysis. Higher odds of SCD-related complications have been reported with higher PoS and lower EImax/EImin. Thus, we propose that red cell function should be included in follow-up care of HCT/GT patients until values normalize and clinical relevance is further assessed.