Virulence and resistance profiling of Staphylococcus aureus isolated from subclinical bovine mastitis in the Pakistani Pothohar region.

Mastitis is considered one of the most widespread infectious disease of cattle and buffaloes, affecting dairy herds. The current study aimed to characterize the Staphylococcus aureus isolates recovered from subclinical mastitis animals in Pothohar region of the country. A total of 278 milk samples from 17 different dairy farms around two districts of the Pothohar region, Islamabad and Rawalpindi, were collected and screened for sub clinical mastitis using California Mastitis Test. Positive milk samples were processed for isolation of Staphylococcus aureus using mannitol salt agar. The recovered isolates were analyzed for their antimicrobial susceptibility and virulence genes using disc diffusion and PCR respectively. 62.2% samples were positive for subclinical mastitis and in total 70 Staphylococcus aureus isolates were recovered. 21% of these isolates were determined to be methicillin resistant, carrying the mecA gene. S. aureus isolates recovered during the study were resistant to all first line therapeutic antibiotics and in total 52% isolates were multidrug resistant. SCCmec typing revealed MRSA SCCmec types IV and V, indicating potential community-acquired MRSA (CA-MRSA) transmission. Virulence profiling revealed high prevalence of key genes associated with adhesion, toxin production, and immune evasion, such as hla, hlb, clfA, clfB and cap5. Furthermore, the Panton-Valentine leukocidin (PVL) toxin, that is often associated with recurrent skin and soft tissue infections, was present in 5.7% of isolates. In conclusion, the increased prevalence of MRSA in bovine mastitis is highlighted by this study, which also reveals a variety of virulence factors in S. aureus and emphasizes the significance of appropriate antibiotic therapy in combating this economically burdensome disease.

Association of polymorphism in the promotor area of the caprine BMPR1B gene with litter size and body measurement traits in Damani goats.

This study aimed to explore polymorphisms in the promoter region of the caprine BMPR1B (Bone morphogenetic protein receptor 1 beta) gene and its association with body measurement and litter size traits in Damani does. A total of 53 blood samples were collected to analyze the association between the BMPR1B gene polymorphism and 11 phenotypic traits in Damani female goats. The results revealed that three novel SNPs were identified in the promoter region of the caprine BMPR1B gene, including g.67 A > C (SNP1), g.170 G > A(SNP2), and g.501A > T (SNP3), among which the SNP1 and SNP2 were significantly (p < 0.05) associated with litter size and body measurement traits in Damani goats. In SNP1 the AC genotype could be used as a marker for litter size, and the CC genotype for body weight in Damani goats. In SNP2, the genotype GG was significantly (p < 0.05) associated with ear and head length. Therefore, we can conclude from the present study, that genetic variants AC and CC of the caprine BMPR1B gene could be used as genetic markers for economic traits through marker-assisted selection for the breed improvement program of the Damani goat.

Analysis of the Effectiveness of Second Attempt Endoscopic Retrograde Cholangiopancreatography (ERCP) 24 Hours (Second Day) After Primary Failure.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is a minimally invasive intervention that has established itself as the gold standard therapeutic option for various pancreaticobiliary conditions. Deep cannulation of the common bile duct (CBD) is essential in ERCP. However, cannulation is not possible in approximately 20% of the cases with the usual techniques even when performed by highly trained professionals or at major healthcare institutions. In case of failure on the first attempt, alternative choices include redoing the procedure (on the second attempt) or moving on to more proficient endoscopic methods such as endoscopic ultrasound (EUS) or radiology-aided techniques (rendezvous procedures), totally percutaneous approaches, or surgical treatments. OBJECTIVE: To analyze the effectiveness of the second attempt ERCP 24 hours (second day) after primary failure. METHODOLOGY: This analytical study was conducted to check the outcomes of second attempt ERCP in patients with prior failed cannulation, from June 20, 2023, to November 20, 2023, at the Department of Gastroenterology, Lady Reading Hospital, Peshawar. Patients of either sex, aged >16 years with failed biliary cannulation, and who were otherwise clinically stable were included in the study. Patients with surgically modified anatomy, an unidentified main duodenal papilla, or a history of sphincterotomy at another setup were excluded. Outcomes were assessed in terms of gaining deep biliary access (cannulation) using a therapeutic duodenoscope and endoscopy system supported by a fluoroscope while using a wire-guided sphincterotome. Factors linked to second ERCP cannulation success or failure were analyzed using SPSS version 24. RESULTS: Ninety-four patients were enrolled including 61 (64.9%) males and 33 (35.10%) females. The mean age of the participants was 39.01±14.831 years. The most common indication for the intervention was CBD stones, which were present in 70 (74.5%) patients. Successful cannulation on the second attempt was achieved in 72 (76.6%) patients. Experienced endoscopists achieved a greater proportion of successful cannulation (86.8%) compared to 33.3% by endoscopists with lower experience (p-value: <0.001). Logistic regression analysis was conducted to predict the outcomes (cannulation), which revealed an odds ratio for endoscopist experience of 33.604 (95% confidence interval: 6.948-162.52). CONCLUSION: A second ERCP attempt 24 hours after the primary failed attempt appears to be the best course of action for the majority of clinically stable patients.

In Silico Identification and Characterization of Rare Cold Inducible 2 (RCI2) Gene Family in Cotton.

RCI2/PMP3s are involved in biotic and abiotic stresses and have an influence on the regulation of many genes. RCI2/PMP3 genes, which particularly encode small membrane proteins of the PMP3 family, are involved in abiotic stress responses in plants. In this work, in silico studies were used to investigate RCI2's potential function in stress tolerance and organogenesis. We conducted an extensive study of the RCI2 gene family and revealed 36 RCI2 genes from cotton species that were distributed over 36 chromosomes of the cotton genome. Functional and phylogenetic examination of the RCI2/PMP3 gene family has been studied in Arabidopsis, but in cotton, the RCI2/PMP3 genes have not yet been studied. Phylogenetic and sequencing studies revealed that cotton RCI2s are conserved, with most of them categorized into six distinct clades. A chromosome distribution and localization study indicated that cotton RCI2 genes were distributed unevenly on 36 chromosomes with segmental duplications, suggesting that the cotton RCI2 family is evolutionarily conserved. Many cis-elements related to stress responsiveness, development, and hormone responsiveness were detected in the promoter regions of the cotton RCI2. Moreover, the 36 cotton RCI2s revealed tissue-specific expression patterns in the development of cotton performed by transcriptome analysis. Gene structure analysis indicated that nearly all RCI2 genes have two exons and one intron. All of the cotton RCI2 genes were highly sensitive to drought, abscisic acid, salt, and cold treatments, demonstrating that they may be employed as genetic objects to produce stress-resistant plants.

Incidence of aflatoxin M1 in cows' milk in Pakistan, effects on milk quality and evaluation of therapeutic management in dairy animals.

The present study was aimed at measuring the concentration of aflatoxin M1 (AFM1) in the milk of Holstein Friesian cows, its effect on the milk quality and seasonal trends, as well as to investigate the efficacy of a commercial clay-based toxin binder. For this purpose, milk samples from dairy cows (n = 72) were collected and assayed for AFM1 before employing a clay-based toxin binder. The milk samples (n = 72) were collected from selected animals, revealing that 69.4% of the milk samples had AFM1 levels above the United States permissible limit (0.5 µg/kg). The incidence of AFM1 in milk during the winter and summer was 82.5% and 53.1%, respectively. Owing to the presence of AFM1, the level of milk fat, solids-not-fat, and protein were found to be low. Subsequently, the affected animals were divided into two groups, i.e., AFM1 positive control (n = 10) and the experimental group (n = 40). The experimental group of animals were fed the clay-based toxin binder at 25 g/animal/day. A progressive decrease of 19.8% in the AFM1 levels was observed on day 4 and on day 7 (53.6%) in the treatment group. Furthermore, the fat, solids-non-fat and protein increased significantly in the milk. In conclusion, a high level of AFM1 contamination occurs in the milk in Pakistan, affecting the quality of the milk production. Clay-based toxin binders may be used to ensure the milk quality and to protect the animal and consumer health.

Expression of IFN-Gamma is significantly reduced during severity of covid-19 infection in hospitalized patients.

Cytokines play an important role in SARS-CoV-2 infection progression and severity. A number of inflammatory cytokines have been directly associated with disease severity including IL-6 (interleukin-6), IL-10, TNF-α (tumor necrosis factor alpha), IFN-γ (interferon-gamma). Here, in this study, the aim was to better understand the interplay between host immune response mediated by cytokines and severity of SARS-CoV-2 infection by assessing cytokine expression. Therefore, we measured expression levels of a total of 12 genes (IFNA-1, IFN-γ, IL-1α, IL-1ß, IL-4, IL-6, IL-7, IL-10, IL-11, IL-13, IL-15, and IL-27) encoding inflammatory, anti-inflammatory and regulatory cytokines using QRT-PCR in hospitalized patients with severe infection compared to mildly infected. IFN-γ was identified as a potent marker of disease severity as indicated previously. Moreover, levels of IL-7 were also found to be partially reduced in patients compared to the healthy controls and linked negatively to disease severity. Identification of these cytokines may be helpful in not only understanding disease pathogenesis but also in better management of the patients after covid infection.

Correction: Wang et al. A VLP-Based Vaccine Displaying HBHA and MTP Antigens of Mycobacterium tuberculosis Induces Potentially Protective Immune Responses in M. tuberculosis H37Ra Infected Mice. Vaccines 2023, 11, 941.

Concerns were brought to the attention of the journal's editorial office after the paper was published [...].

Thermodynamic irreversibility effects with Marangoni convection for third grade nanofluid flow.

In this study, an analysis was performed to investigate the thermal and mass transport of radiative flow of a third-grade nanofluid with magnetohydrodynamic. The analysis concerns two-dimensional flow around an infinite disk. Heat transport is studied via heat generation/absorption, thermal radiation and Joule heating. Chemical reaction with activation energy is also considered. The nanofluid characteristics, including Brownian motion and thermophoretic diffusion, are explored via the Buongiorno model. Entropy analysis is also conducted. Moreover, the surface tension is assumed to be a linear function of concentration and temperature. Through adequate dimensionless variables, governed PDEs are non-dimensionlized and then tackled by ND-solve (a numerical method in Mathematica) for solutions purposes. Entropy generation, concentration, velocity, Bejan number and temperature are plotted as functions of the involved physical parameters. It is noticed that higher Marangoni number intensify velocity however it causes a decrease in the temperature. Entropy rate and Bejan number boost for large value of diffusion parameter.

A VLP-Based Vaccine Displaying HBHA and MTP Antigens of Mycobacterium tuberculosis Induces Protective Immune Responses in M. tuberculosis H37Ra Infected Mice.

Heparin-binding hemagglutinin (HBHA) and M. tuberculosis pili (MTP) are important antigens on the surface of Mycobacterium tuberculosis. To display these antigens effectively, the fusion protein HBHA-MTP with a molecular weight of 20 kD (L20) was inserted into the receptor-binding hemagglutinin (HA) fragment of influenza virus and was expressed along with matrix protein M1 in Sf9 insect cells to generate influenza virus-like particles (LV20 in short). The results showed that the insertion of L20 into the envelope of the influenza virus did not affect the self-assembly and morphology of LV20 VLPs. The expression of L20 was successfully verified by transmission electron microscopy. Importantly, it did not interfere with the immunogenicity reactivity of LV20 VLPs. We demonstrated that LV20 combined with the adjuvant composed of DDA and Poly I: C (DP) elicited significantly higher antigen-specific antibodies and CD4+/CD8+ T cell responses than PBS and BCG vaccination in mice. It suggests that the insect cell expression system is an excellent protein production system, and LV20 VLPs could be a novel tuberculosis vaccine candidate for further evaluation.

Impact of Air Pollution (PM2.5) on Child Mortality: Evidence from Sixteen Asian Countries.

Air pollution in Asian countries represents one of the biggest health threats given the varied levels of economic and population growth in the recent past. The quantification of air pollution (PM2.5) vis à vis health problems has important policy implications in tackling its health effects. This paper investigates the relationship between air pollution (PM2.5) and child mortality in sixteen Asian countries using panel data from 2000 to 2017. We adopt a two-stage least squares approach that exploits variations in PM2.5 attributable to economic growth in estimating the effect on child mortality. We find that a one-unit annual increase in PM2.5 leads to a nearly 14.5% increase in the number of children dying before the age of five, suggesting the severity of the effects of particulate matter (PM2.5) on health outcomes in sixteen Asian countries considered in this study. The results of this study suggest the need for strict policy interventions by governments in Asian countries to reduce PM2.5 concentration alongside environment-friendly policies for economic growth.

In silico analysis of epitope-based vaccine candidate against tuberculosis using reverse vaccinology.

Tuberculosis (TB) kills more individuals in the world than any other disease, and a threat made direr by the coverage of drug-resistant strains of Mycobacterium tuberculosis (Mtb). Bacillus Calmette-Guérin (BCG) is the single TB vaccine licensed for use in human beings and effectively protects infants and children against severe military and meningeal TB. We applied advanced computational techniques to develop a universal TB vaccine. In the current study, we select the very conserved, experimentally confirmed Mtb antigens, including Rv2608, Rv2684, Rv3804c (Ag85A), and Rv0125 (Mtb32A) to design a novel multi-epitope subunit vaccine. By using the Immune Epitopes Database (IEDB), we predicted different B-cell and T-cell epitopes. An adjuvant (Griselimycin) was also added to vaccine construct to improve its immunogenicity. Bioinformatics tools were used to predict, refined, and validate the 3D structure and then docked with toll-like-receptor (TLR-3) using different servers. The constructed vaccine was used for further processing based on allergenicity, antigenicity, solubility, different physiochemical properties, and molecular docking scores. The in silico immune simulation results showed significant response for immune cells. For successful expression of the vaccine in E. coli, in-silico cloning and codon optimization were performed. This research also sets out a good signal for the design of a peptide-based tuberculosis vaccine. In conclusion, our findings show that the known multi-epitope vaccine may activate humoral and cellular immune responses and maybe a possible tuberculosis vaccine candidate. Therefore, more experimental validations should be exposed to it.

The Systematic Review and Meta-Analysis on the Immunogenicity and Safety of the Tuberculosis Subunit Vaccines M72/AS01E and MVA85A.

Background: Tuberculosis (TB) is a severe infectious disease with devastating effects on global public health. No TB vaccine has yet been approved for use on latent TB infections and healthy adults. In this study, we performed a systematic review and meta-analysis to evaluate the immunogenicity and safety of the M72/AS01E and MVA85A subunit vaccines. The M72/AS01E is a novel peptide-based vaccine currently in progress, which may increase the protection level against TB infection. The MVA85A was a viral vector-based TB subunit vaccine being used in the clinical trials. The vaccines mentioned above have been studied in various phase I/II clinical trials. Immunogenicity and safety is the first consideration for TB vaccine development. Methods: The PubMed, Embase, and Cochrane Library databases were searched for published studies (until October 2019) to find out information on the M72/AS01E and MVA85A candidate vaccines. The meta-analysis was conducted by applying the standard methods and processes established by the Cochrane Collaboration. Results: Five eligible randomized clinical trials (RCTs) were selected for the meta-analysis of M72/AS01E candidate vaccines. The analysis revealed that the M72/AS01E subunit vaccine had an abundance of polyfunctional M72-specific CD4+ T cells [standardized mean difference (SMD) = 2.37] in the vaccine group versus the control group, the highest seropositivity rate [relative risk (RR) = 5.09]. The M72/AS01E vaccinated group were found to be at high risk of local injection site redness (RR = 2.64), headache (RR = 1.59), malaise (RR = 3.55), myalgia (RR = 2.27), fatigue (RR = 2.16), pain (RR = 3.99), swelling (RR = 5.09), and fever (RR = 2.04) compared to the control groups. The incidences of common adverse events of M72/AS01E were local injection site redness, headache, malaise, myalgia, fatigue, pain, swelling, fever, etc. Six eligible RCTs were selected for the meta-analysis on MVA85A candidate vaccines. The analysis revealed that the subunit vaccine MVA85A had a higher abundance of overall pooled proportion polyfunctional MVA85A-specific CD4+ T cells SMD = 2.41 in the vaccine group vs. the control group, with the highest seropositivity rate [estimation rate (ER) = 0.55]. The MVA85A vaccinated group were found to be at high risk of local injection site redness (ER = 0.55), headache (ER = 0.40), malaise (ER = 0.29), pain (ER = 0.54), myalgia (ER = 0.31), and fever (ER = 0.20). The incidences of common adverse events of MVA85A were local injection site redness, headache, malaise, pain, myalgia, fever, etc. Conclusion: The M72/AS01E and MVA85A vaccines against TB are safe and had immunogenicity in diverse clinical trials. The M72/AS01E and MVA85A vaccines are associated with a mild adverse reaction. The meta-analysis on immunogenicity and safety of M72/AS01E and MVA85A vaccines provides useful information for the evaluation of available subunit vaccines in the clinic.

Enteric Fever Complicated by Intestinal Perforation in Children: A Persistent Health Problem Requiring Surgical Management.

OBJECTIVE: To evaluate clinical presentation and surgical outcome in children with enteric perforation. METHODS: A descriptive retrospective study was conducted in Department of Paediatric Surgery at National Institute of Child Health, Karachi from August 2016 and September 2019, in children 12 years of age and under with diagnosis of enteric perforation. Data about age, gender, duration of illness, hemodynamic status and baseline investigation on admission was reviewed. Details about patients operated early and those who required prolong resuscitation and were operated after 24 hours of admission, need for tube laparostomy, operative findings, type of surgical procedure performed and post-operative outcome were reviewed. Data was analyzed using SPSS version 22. RESULTS: Ninety-seven patients, 60(61.85%) males and 37(38.14%) females were managed during the study period with age ranged from 3-12 years (mean 7.82, ± 2.94 years).and duration of symptoms ranged from 7-30 days (mean 15.56, ± 9.39days). High grade fever and abdominal pain were seen in all patients (100%). Pneumoperitoneum was noted in 71(73.19%) cases on X-ray abdomen. Fifty-one (52.57%) children were anemic and required blood transfusion before surgery. Seventy-one (73.19) patients were optimized and operated within 24 hours while 28(28.86%) cases required more resuscitation so tube laparostomy was done initially and operated after 24 hours. Seventy nine (81.44%) cases had single perforation, 14(14.43%) cases had multiple and four had sealed perforation. Primary repair of perforation was done in 37(38.14%) cases, while ileostomy in 65(76.01%) cases. Postoperatively wound infection was seen in 71(73.19%) cases, intra-abdominal collections in 31(31.95%) and burst abdomen in nine (9.27%) cases. Overall mortality was 12.37%. Till date in 47 patients (72.30%) reversal of stoma has been done. CONCLUSIONS: Enteric perforation in children presents usually with hemodynamic instability and sepsis due to prolong period of illness. Therefore, regardless of surgical procedure performed it is associated with high morbidity and mortality.

Impact of Urbanization and Economic Growth on CO2 Emission: A Case of Far East Asian Countries.

Rising CO2 emission constitute a great threat to the world environment and public health. This study examines the major determinants of CO2 emissions in Far East countries in the period of 1980 to 2017. We adopt a panel data-fixed effect model that accounts for time-invariant country-specific characteristics that may create omitted-variable bias. We also additionally take care of the time trend by applying an annual fixed effect into our model. The study finds that urbanization, economic growth and trade openness significantly determine CO2 emission in the selected countries. Thus, the main policy suggestions are (a) to encourage green and sustainable urbanization, as it helps in economic progress but not at the expense of environmental deterioration; (b) to strategically regulate and improve industrial structure; and (c) enhance sharing of renewable energy in total energy consumption.

Assessing the fate of recombinant plant DNA in rabbit's tissues fed genetically modified cotton.

Various feeding studies have been conducted with the different species of animals to evaluate the possible transfer of transgenic DNA (tDNA) from genetically modified (GM) feed into the animal tissues. However, the conclusions drawn from most of such studies are sometimes controversial. Thus, in the present study, an attempt has been made to evaluate the fate of tDNA in rabbits raised on GM cotton-based diet through PCR analysis of the DNA extracted specifically from blood, liver, kidney, heart and intestine (jejunum). A total of 48 rabbits were fed a mixed diet consisting variable proportions of transgenic cottonseeds meal (i.e. 0% w/w, 20% w/w, 30% w/w and 40% w/w) for 180 days. The presence of transgenic DNA fragments (Cry1Ac, Cry2A and CP4 EPSPS) or plant endogenous gene (Sad1) was traced in those specific tissues and organs. The presence of ß-actin (ACTB) was also monitored as an internal control. Neither the transgenic fragments (459 bp of Cry1Ac gene, 167 bp of Cry2A gene and111 bp of CP4 EPSPS gene) nor cotton endogenous reference gene (155 bp of Sad1) could be detected in any of the DNA samples extracted from the rabbit's tissues in both control and transgenic groups. However, 155 bp fragment of the rabbit's reference gene (ACTB) was recovered in all the DNA samples extracted from rabbit tissues. The results obtained from this study revealed that both plant endogenous and transgenic DNA fragments have same fate in rabbit's tissues and were efficiently degraded in the gastrointestinal tract (GIT).

Synthesis, structural characterization and catalytic application of citrate-stabilized monometallic and bimetallic palladium@copper nanoparticles in microbial anti-activities.

In this research work, copper (Cu), palladium (Pd) and their bimetallic palladium@ copper (Pd@Cu) nanoparticles were synthesized using trisodium citrate as a stabilizing agent using the known chemical reduction method. The synthesized Cu, Pd and Pd@Cu nanoparticles were characterized by the ultraviolet-visible spectroscopy, scanning electron microscopy and X-ray diffraction spectroscopy, respectively. The different volumes of trisodium citrate were used for the stability of synthesized monometallic Cu, Pd and bimetallic Pd@Cu nanoparticles. The synthesized Cu, Pd and their bimetallic Pd@Cu nanoparticles were used as catalysts for the reduction of 4-nitrophenol in the presence of NaBH4. The bimetallic Pd@Cu nanoparticles had efficient catalytic activities with a high rate constant (1.812 min-1) as compared to monometallic Cu (0.3322 min-1) and Pd (0.2689 min-1) nanoparticles, respectively. The correlation coefficient (R2) was found to be 0.99 for these three nanoparticles. Meanwhile, the effect of Cu, Pd and bimetallic Pd@Cu nanoparticles was checked on the physiology of specific different micro-organism strains. The bimetallic Pd@Cu nanoparticles reported the maximum resistance at maximum level the growth of bacterial strain and had observed a smooth antibacterial graph than the monometallic analogs.

Bacterial endophytes enhance phytostabilization in soils contaminated with uranium and lead.

The combined use of plants and bacteria is a promising approach for the remediation of polluted soil. In the current study, the potential of bacterial endophytes in partnership with Leptochloa fusca (L.) Kunth was evaluated for the remediation of uranium (U)- and lead (Pb)-contaminated soil. L. fusca was vegetated in contaminated soil and inoculated with three different endophytic bacterial strains, Pantoea stewartii ASI11, Enterobacter sp. HU38, and Microbacterium arborescens HU33, individually as well as in combination. The results showed that the L. fusca can grow in the contaminated soil. Bacterial inoculation improved plant growth and phytoremediation capacity: this manifested in the form of a 22-51% increase in root length, 25-62% increase in shoot height, 10-21% increase in chlorophyll content, and 17-59% more plant biomass in U- and Pb-contaminated soils as compared to plants without bacterial inoculation. Although L. fusca plants showed potential to accumulate U and Pb in their root and shoot on their own, bacterial consortia further enhanced metal uptake capacity by 53-88% for U and 58-97% for Pb. Our results indicate that the combination of L. fusca and endophytic bacterial consortia can effectively be used for the phytostabilization of both U- and Pb-contaminated soils.

Mutations in phosphodiesterase 6 identified in familial cases of retinitis pigmentosa.

To delineate the genetic determinants associated with retinitis pigmentosa (RP), a hereditary retinal disorder, we recruited four large families manifesting cardinal symptoms of RP. We localized these families to regions on the human genome harboring the α and ß subunits of phosphodiesterase 6 and identified mutations that were absent in control chromosomes. Our data suggest that mutations in PDE6A and PDE6B are responsible for the retinal phenotype in these families.

Pathogenic mutations in TULP1 responsible for retinitis pigmentosa identified in consanguineous familial cases.

PURPOSE: To identify pathogenic mutations responsible for autosomal recessive retinitis pigmentosa (arRP) in consanguineous familial cases. METHODS: Seven large familial cases with multiple individuals diagnosed with retinitis pigmentosa were included in the study. Affected individuals in these families underwent ophthalmic examinations to document the symptoms and confirm the initial diagnosis. Blood samples were collected from all participating members, and genomic DNA was extracted. An exclusion analysis with microsatellite markers spanning the TULP1 locus on chromosome 6p was performed, and two-point logarithm of odds (LOD) scores were calculated. All coding exons along with the exon-intron boundaries of TULP1 were sequenced bidirectionally. We constructed a single nucleotide polymorphism (SNP) haplotype for the four familial cases harboring the K489R allele and estimated the likelihood of a founder effect. RESULTS: The ophthalmic examinations of the affected individuals in these familial cases were suggestive of RP. Exclusion analyses confirmed linkage to chromosome 6p harboring TULP1 with positive two-point LOD scores. Subsequent Sanger sequencing identified the single base pair substitution in exon14, c.1466A>G (p.K489R), in four families. Additionally, we identified a two-base deletion in exon 4, c.286_287delGA (p.E96Gfs77*); a homozygous splice site variant in intron 14, c.1495+4A>C; and a novel missense variation in exon 15, c.1561C>T (p.P521S). All mutations segregated with the disease phenotype in the respective families and were absent in ethnically matched control chromosomes. Haplotype analysis suggested (p<10(-6)) that affected individuals inherited the causal mutation from a common ancestor. CONCLUSIONS: Pathogenic mutations in TULP1 are responsible for the RP phenotype in seven familial cases with a common ancestral mutation responsible for the disease phenotype in four of the seven families.

Loss of function mutations in RP1 are responsible for retinitis pigmentosa in consanguineous familial cases.

PURPOSE: This study was undertaken to identify causal mutations responsible for autosomal recessive retinitis pigmentosa (arRP) in consanguineous families. METHODS: Large consanguineous families were ascertained from the Punjab province of Pakistan. An ophthalmic examination consisting of a fundus evaluation and electroretinography (ERG) was completed, and small aliquots of blood were collected from all participating individuals. Genomic DNA was extracted from white blood cells, and a genome-wide linkage or a locus-specific exclusion analysis was completed with polymorphic short tandem repeats (STRs). Two-point logarithm of odds (LOD) scores were calculated, and all coding exons and exon-intron boundaries of RP1 were sequenced to identify the causal mutation. RESULTS: The ophthalmic examination showed that affected individuals in all families manifest cardinal symptoms of RP. Genome-wide scans localized the disease phenotype to chromosome 8q, a region harboring RP1, a gene previously implicated in the pathogenesis of RP. Sanger sequencing identified a homozygous single base deletion in exon 4: c.3697delT (p.S1233Pfs22*), a single base substitution in intron 3: c.787+1G>A (p.I263Nfs8*), a 2 bp duplication in exon 2: c.551_552dupTA (p.Q185Yfs4*) and an 11,117 bp deletion that removes all three coding exons of RP1. These variations segregated with the disease phenotype within the respective families and were not present in ethnically matched control samples. CONCLUSIONS: These results strongly suggest that these mutations in RP1 are responsible for the retinal phenotype in affected individuals of all four consanguineous families.