Leg Defects Research Articles

The Imageology Study and Clinical Application of Perforating Branch of Posterior Tibial Artery.

It is necessary to precisely locate the branches for better result of flap transplantation for the high variability of perforating branches of posterior tibial artery (PTA). In the research, digital subtraction angiography (DSA) and high-frequency ultrasound are jointly used to study the distribution and exact location of PTA perforating branches to guide clinical practice. From January 2020 to December 2022, 16 patients underwent DSA examination and 5 of them accepted further high-frequency ultrasound examination. The authors analyzed the distribution, number, location, direction, and lengths of PTA branches and used PTA perforator flaps to repair middle and inferior lower leg defects according to the above imaging findings. The donor site was repaired with skin grafts or a sequential PTA perforator flap. A total of 81 branches of PTA were identified in 16 patients. Most of the perforating branches were in the middle and distal thirds of tibia. There was a significant correlation between the length of perforating branches and their perforating sites. Cluster analysis showed that larger branches appeared most frequently in the range of 15 to 20cm from the tip of the inner ankle. 5 cases of PTA perforator flaps survived well. DSA can clearly show the distribution of PTA and its branches, especially the dominant ones. The imaging findings can effectively guide PTA perforator flap design and harvesting, and thus improve the result of flap transplantation.

Distally based sural flaps for soft tissue defects following traumatic osteomyelitis of lower leg and foot.

This retrospective study aimed to determine the incidence and risk factors for osteomyelitis recurrence and present our experiences in treating traumatic osteomyelitis in the lower leg and foot. We retrospectively reviewed data from 174 patients with distally based sural flaps for treating traumatic osteomyelitis with soft tissue defects in the lower leg and foot from November 2003 to February 2021. Possible risk factors for osteomyelitis recurrence were compared between the osteomyelitis control and recurrence groups. A total of 162 (93.1%) flaps survived uneventfully, while 12 (6.9%) flaps developed partial necrosis. Five patients had a bone defect with an average length of 5cm. The free vascularized bone grafts were performed in two patients, and bone transportations were performed in three patients. All patients were followed up with an average period of 72.8 months. There were 152 patients (87.4%) in control group and 22 patients (12.6%) in recurrence group. The recurrence rates of osteomyelitis were significantly higher when the patient's age was 40 years or more and the duration was 10 weeks or more (P < 0.05). Cierny-Mader (C-M) classification type IV osteomyelitis was also significantly associated with osteomyelitis recurrence (p = 0.049). This flap combined with appropriate osteomyelitis treatment was an effective method to treat traumatic osteomyelitis of lower leg and foot with a soft tissue defect. Both patient age ≥ 40 years old and C-M type IV osteomyelitis were nonnegligible risk factors for osteomyelitis recurrence.

Cross-Leg Microvascular Free Anterolateral Thigh Flap as a Safe, Viable, and Reserve Option for Reconstruction in a Vessel-Depleted Limb

AbstractWe present the case of a 36-year-old male patient with a posttraumatic composite defect of the lower two-thirds of the anterior aspect of the left leg with exposed necrotic tibia in an old, neglected type 3b fracture of the tibia of 9-month duration. The options for definitive soft-tissue cover include microvascular free tissue transfer and cross-leg flaps. In trauma cases, the surrounding tissue is usually damaged, and the recipient vessels are frequently implicated, ruling out the use of a microvascular free flap. Cross-leg flaps are unachievable due to large defect sizes and lack of appropriate donor tissue. In this case report, we highlight the use of cross-leg microvascular free anterolateral thigh (ALT) flap cover for the composite leg defect. By presenting our case, we aim to advocate the clinical application of cross-leg free flap surgery in vessel-depleted limbs as a safe and viable option.

Artificial deformity creation in treatment of soft tissue wounds and lower leg bones defect: a case report

Background. The problem of treating wounded patients with defects of soft tissues and bones of the extremities continues to be relevant. One of the ways to close soft tissue defects, especially in case of bone tissue loss, after open fractures of the extremities is acute shortening and creation of artificial angular deformity of the segment. The aim of the study — to demonstrate the possibilities of acute shortening and angulation of the segment as a technique to replace soft tissue and bone defects in treatment of a patient with a gunshot wound to the lower leg. Case description. A 30-year-old wounded man was admitted to the clinic with an extensive defect in soft tissues and bones of the lower leg in the middle third. To reduce the wound size, acute shortening and angulation of the lower leg was performed. The intentional angular deformation was 24º, shortening — up to 8 cm. The residual soft tissue wound defect was closed with local tissues and split skin autograft. The tibia was fixed by the Ilizarov hinge-distraction apparatus with following gradual correction of the angular deformity. After that, one performed osteotomy of the tibia in order to eliminate shortening with the Ilizarov method (the distraction rate of 1 mm per day). After restoring the length of the lower leg, in order to replace the defect along the anterior surface of the tibia, a marginal “flake” was formed from a displaced fragment. At a follow-up examination, in 18 months after the injury the patient walks with full weight bearing on the injured limb without any additional means of support, continues to perform military service duties in accordance with his position. Conclusions. The presented clinical case demonstrates that acute shortening of a limb segment with creation of artificial angular deformity is an effective method for temporary closure of a gunshot defect of soft tissues. The technique allowed closing critical soft tissue defect of the lower leg and restoring the anatomy (length) of the segment. Consequently, one was able to achieve satisfactory treatment results and restore the functions of an injured limb. Besides, acute temporary shortening technique eliminated the need to perform technically sophisticated and lengthy microsurgical reconstructions, which are associated with a flap replacement for closure of soft tissue defects in a shotgun fracture area.

Use of reverse sural artery flap for reconstruction of defects of distal leg, ankle and foot

Use of reverse sural artery flap for reconstruction of defects of distal leg, ankle and foot

Posterior Tibial Artery Perforator Based Propeller Flap for Reconstruction of 143 Skin and Soft Tissue Defect Around Ankle Joint

Background: Soft tissue coverage of distal leg and ankle region represents a challenge and such defect usually requires a free flap. However, this needs facility of microsurgery, may lead to donor site morbidity and is time consuming. With the introduction of perforator flap, management of small and medium size defects of distal leg and ankle region is easier, less time consuming, and with minimal donor site morbidity. When local perforator flap is designed as propeller and rotated to 180-degree, donor site can be closed primarily and increases the distance crossed by flap, thus increasing versatility. Objectives: To observe the outcome of soft tissue coverage of defects around ankle joint by posterior tibial artery perforator based propeller flaps. Methods: This was a prospective type of observational study carried out on 20 patients with skin and soft tissue defects in and around ankle joint for a period of 14 months in the Department of Burn and Plastic Surgery, Dhaka Medical College and Hospital. Results: Among 20 cases 17 were male and 3 females; age ranged from 11 to 60 years. Post operative outcome of flap were excellent in 11 cases, good in 6 cases, poor in 3 cases as per defined criteria. Uneventful outcome was observed in 14 cases and minor complications were observed in 5 cases; and total flap loss occurred in 1 case which required revision surgery. Conclusions: Perforator flap provides adequate soft tissue coverage for small &amp; medium size wound around ankle. It is an easy, reliable &amp; effective procedure with reasonable outcome. J Dhaka Med Coll. 2022; 31(2) : 243-250

Versatility of Proximal Sural Island Sensate Fasciocutaneous Flap in Reconstruction of Soft Tissue Defects of Knee and Proximal Leg

Background: The proximal sural island sensate (PSIS) fasciocutaneous flap presents an ideal alternative in reconstruction of defects of the knee and proximal leg. It provides a thin sensate flap with good aesthetic outcomes and reduced donor site morbidity. However, only limited reports exist in the literature about this flap.Methods: This is a retrospective study done between December 2018 and December 2021 including 30 patients, among which seven cases had defects located on the knee and 23 cases in the proximal part of the leg. Mean age of the study population was 41 years. The maximum flap size was 8×12 cm, while the maximum pedicle length was 15 cm.Results: All 30 flaps survived well with only minimal complications occurring in a few patients such as epidermal loss and distal tip necrosis. No arterial or venous crisis occurred postoperatively in any case. Donor sites were managed with one-stage primary closure or split-thickness skin grafts. Functional deficits were not detected in any of the cases.Conclusion: We found the PSIS fasciocutaneous flap to be a simple and reliable technique to perform. The flap offers extensive coverage, reaching from the knee to the proximal leg, and provides thin, pliable, and sensate skin, resulting in excellent aesthetic and functional outcomes.

Outcome of Delayed Distally Based Sural Flap for Distal Tibial and Foot Defects

Abstract: Background: Lower limb defects can be tricky to repair. We have limited options for reconstruction in the leg and foot region. Sural flap is considered as the workhorse for reconstruction of these defects. We present our case series of delayed reverse sural flap. Objective: To determine the outcome of Delayed Distally based sural flaps for distal tibial and foot defects. Materials and Methods: Study was carried out at plastic and reconstructive unit HMC and MMC. Over a period of 10 years from January, 2009 to December, 2018. This is a cross sectional study, presenting with soft tissue defects of foot. Patients presented in the emergency, as an outpatient or as referrals from another center. All patients were admitted and operated as elective cases. Result: In 24 patients, there were no complications. Two patients (6%) had partial flap loss and required revision surgeries. Two patients had marginal flap necrosis and were treated conservatively. Conclusion: This study presents our experience with use of reverse sural flap. It provides a reliable option for foot and distal leg defects. It is relatively easy to do and easy to learn. It can be attempted in centers where expertise or facilities for microvascular surgery are not available and in patients who are not ideal candidates for a free flap. Keywords: Sural flap, Foot and leg defects, Delayed reverse sural flap, Peroneal perforators, Fasciocutaneous flap, Sural angiosome.

Genetic background of walking ability and its relationship with leg defects, mortality, and performance traits in turkeys (Meleagris gallopavo)

This study aimed to explore the genetic basis of walking ability and potentially related performance traits in turkey purebred populations. Phenotypic, pedigree, and genomic datasets from 2 turkey lines hatched between 2010 and 2023 were included in the study. Walking ability data, defined based on a scoring system ranging from 1 (worst) to 6 (best), were collected on 192,019 animals of a female line and 235,461 animals of a male line. Genomic information was obtained for 46,427 turkeys (22,302 from a female line and 24,125 from a male line) using a 65K single nucleotide polymorphism (SNP) panel. Variance components and heritability for walking ability were estimated. Furthermore, genetic and phenotypic correlations among walking ability, mortality and disorders, and performance traits were calculated. A genome-wide association study (GWAS) was also conducted to identify SNPs associated with walking ability. Walking ability is moderately heritable (0.23 ± 0.01) in both turkey lines. The genetic correlations between walking ability and the other evaluated traits ranged from -0.02 to -0.78, with leg defects exhibiting the strongest negative correlation with walking ability. In the female line, 31 SNPs were associated with walking ability and overlapped with 116 genes. These positional genes are linked to 6 gene ontology (GO) terms. Notably, genes such as CSRP2, DDX1, RHBDL1, SEZ6L, and CTSK are involved in growth, development, locomotion, and bone disorders. GO terms, including fibronectin binding (GO:0001968), peptide cross-linking (GO:0018149), and catabolic process (GO:0009057), are directly linked with mobility. In the male line, 66 markers associated with walking ability were identified and overlapped with 281 genes. These genes are linked to 12 GO terms. Genes such as RB1CC1, TNNI1, MSTN, FN1, SIK3, PADI2, ERBB4, B3GNT2, and BACE1 are associated with cell growth, myostatin development, and disorders. GO terms in the male line are predominantly related to lipid metabolism. In conclusion, walking ability is moderately heritable in both populations. Furthermore, walking ability can be enhanced through targeted genetic selection, emphasizing its relevance to both animal welfare and productivity.

Lower Third Leg Trauma Management Algorithm; Kasr Alainy Protocol.

Soft tissue defects in the lower third of the leg present significant challenges for surgeons. Despite various options available for soft tissue coverage, selecting the most suitable option is limited by potential complications. In response to this challenge, some surgeons have sought to develop algorithms to guide decision-making in the management of lower leg trauma. This prospective observational cross-sectional study included 53 patients with traumatic injuries to the lower third leg and ankle regions. Each patient underwent a management plan based on our proposed algorithm, which incorporated the utilization of negative pressure wound therapy and dermal substitutes. Outcomes were assessed in terms of the ability to achieve complete coverage, complication rates, duration of hospital stay, and return to normal daily activity. The proposed algorithm proved to be comprehensive and easily applicable, achieving complete coverage in 98.1% of cases. The mean duration for definitive coverage was 21.89 ± 12.84 days, and the majority of cases (81.1%) returned to normal daily activity within a mean duration of 60.69 ± 56.7 days. The use of dermal substitutes resulted in achieving coverage in wounds with exposed structures, with favorable outcomes in cases with a mean size of 11.39 ± 10.05 cm². Our algorithm provides a safe and effective approach to manage traumatic defects of the lower third leg and ankle, considering the patient's general condition and the complexity of the wound. Proper utilization of dermal substitutes and negative pressure wound therapy is emphasized in the algorithm.

Free Flaps in Patients with Advanced Arteriosclerosis of the Tibial Vessels: Mini Vein Graft to the Peroneal Artery.

Lower extremity reconstruction with free flaps in patients with only peroneal artery runoff remains a challenge. Here, we present a novel technique for reconstruction of medial defects in the distal leg using a medial approach to the peroneal artery and a short interposition vein graft anastomosed end to side to the peroneal artery. A retrospective, single-center study was performed including all patients who underwent lower extremity reconstruction with free flaps anastomosed to the peroneal artery using a mini vein graft from November 2020 to March 2022. The primary outcome measure was limb salvage. Secondary endpoints were flap survival and postoperative complications. Seven patients received lower extremity free flap reconstruction with a mini vein graft to the peroneal artery. Flap loss rate was 0%. Limb salvage was achieved in five patients (71%). At 6-month follow-up, all patients were ambulatory. One patient died 1 month after surgery due to heart failure. Mini vein graft to the peroneal artery allows reliable and safe free flap reconstruction of distal leg defects in patients with only peroneal artery runoff.

Exploring the success of fasciocutaneous flap techniques in treating distal leg injuries, a Sub-Saharan African experience from Sudan

BackgroundSoft tissue and bone injuries in the lower extremities associated with high-energy trauma remain a formidable challenge to treat. The timing of the operation, the most suitable type of tissue, and the decision between local or free flap coverage remain under discussion. MethodThis prospective, cohort, multi-center study was conducted in Khartoum, Sudan, from April 2021–September 2021. The study included 70 patients. Data was collected using a questionnaire filled with patients after getting informed consent. ResultsMales were 53(75.7 %) and females were 17(24.3 %). Male to female ratio was 3.1: 1. The mean age of the patients was 27.2 ± 3.4 years. The indications for the use of fascia-cutaneous flap in the management of traumatic soft tissue injuries of distal legs were distal substance loss areas of the leg 55(78.6 %), bone exposure 60(85.7 %), open fracture 29(41.4 %), and tendon exposure 31(44.3 %). The type of fasciocutaneous flap used for the patients in this study was perineal artery flap in 20(28.6 %), sural flap in 19(27.1 %), anterior tibial artery perforator flap in 18(25.7 %), and posterior tibial perforator flap in 13(18.6 %) of the patients in 42(60 %) of the patients, no complications were reported. The reported complications were infection 16(5.7 %), distal flap necrosis 8(11.4 %) and total loss 4(5.7 %). ConclusionDespite advances in microsurgery and free flap use, a fascia-cutaneous flap is still a valid option for distal leg soft tissue reconstruction in settings where this service is unavailable. fasciocutaneous flaps are an excellent option for distal leg defects to cover soft-tissue defects, exposed bones, and tendons.

Resurfacing complex knee and upper third leg defect with reverse vastus lateralis muscle flap in a flap exhausted leg - A case report

Coverage of upper third leg and knee defects are complex and the main supply of pedicled flaps come from the uninjured leg. Hence planning of flaps from leg must be meticulous, because if these fail then reveres flow flaps from thigh or micro vascular surgery will become the only option. Both have their own set of complications and patients who cannot tolerate micro vascular surgery due to their prolonged duration, co morbidities, and severe atherosclerosis of vessels, end up as thigh flaps being the only resort. Thigh flaps come with a set of complications of their own and even these fail, with above knee amputation being the ultimate option, which patient hardly expects as end result with many stages of reconstruction already being done. It’s a nightmare for both surgeon and patient.

Quality of Life After Lower Leg Reconstruction With the Latissimus Dorsi Free Flap in Pediatric Patients.

The latissimus dorsi free flap is a widely used reconstructive technique for complex lower leg defects in the pediatric population due to its reliability and anatomical features. However, the impact of this technique on the postoperative quality of life in children and adolescents, who require appropriate lower extremity function during their developmental period, remains to be analyzed. Patients who underwent microsurgical lower leg reconstruction using the latissimus dorsi flap were analyzed retrospectively. The quality of life of these patients was assessed prospectively using the Lower Extremity Functional Scale (LEFS) at a minimum of 18 months after surgical reconstruction. Sixteen pediatric patients who had severe lower extremity injuries and underwent latissimus dorsi free flap reconstruction met the inclusion criteria. The mean follow-up period was 33.9 months (22-64 months). Two patients experienced postoperative complications: one had partial flap necrosis and surgical site infection, while the other developed a surgical site infection. The LEFS scores ranged from 26 to 80, with a mean score of 64.6. Remarkably, 14 of 16 patients achieved LEFS scores consistent with at least the 10th percentile when compared with normative data. Patients with severe associated fractures presented with the lowest scores. Based on our findings, the latissimus dorsi flap is reaffirmed to be an excellent choice for lower leg reconstruction in the pediatric population. It effectively restores the quality of life in patients who have experienced moderate to severe lower extremity injuries.

Long-Term Treatment Outcome of a Patient with Extensive Circular Soft Tissue Defect of the Distal Third of the Lower Extremity: A Case Report

Background. Open fractures of the lower leg bones associated with extensive soft tissue defects are among the most challenging in trauma surgery.&#x0D; Aim of the study is to demonstrate the possibilities of modern reconstructive surgery in the treatment of severe polystructural trauma of the lower limb using a unique clinical example.&#x0D; Case description. An 18-year-old patient sustained a polytrauma which included head and extremities injuries as a result of a fall under a moving train. Due to the signs of uncompensated ischemia of the left lower limb at the first stage of treatment the patient underwent emergency left tibial artery thrombectomy, repeated debridement of the left lower leg wound, remounting of the external fixator, and lumbar sympathectomy. The second stage of surgical treatment included free transplantation of a vascularized anterolateral flap of the right thigh. The third stage included staged necrectomies; replacement of the soft tissue defect of the posteromedial surface of the distal lower leg with a sural fasciocutaneous vascularized flap on the distal vascular pedicle from the contralateral tibia; the fourth stage included cutting off the fasciocutaneous cross flap. At the follow-up, 2 years after the end of the treatment the patient complained of persisting swelling of the foot, which occurred during prolonged standing in the upright position and required elastic compression of the ankle joint. The cause of the swelling was impaired lymphatic outflow due to the damage to all venous collaterals in the injury area. She walks with full load on the injured limb without additional support. There is no pain syndrome, foot sensitivity is fully preserved.&#x0D; Conclusion. Presented clinical case demonstrates the possibility of successful replacement of an extensive circular defect of the distal lower leg using sequentially free and non-free vascularized tissue complexes.

Propeller Flap: A Feasible Flap for Distal Third of Leg Defects – Two Cases Done at the Plastic Surgery Unit of the Greater Accra Regional Hospital

Introduction: The traditional way of reconstructing soft tissue defects of the lower limb utilized muscle flaps as the ‘gold standard’ for Gustillo Anderson Grade III B fractures of the upper and middle thirds of the leg. Defects of the lower third of the leg are usually reconstructed with free flaps because of paucity and decreased reach of muscles. In resource constrained environments where free flaps are not routine with high failure rates, fasciocuataneous flaps are the only option left. We present our experience with the novel pedicled propeller perforator flaps for reconstruction of soft tissue defects in the lower limb. Case Presentation: Between June and October 2020, 2 consecutive patients - a 34-year-old male and a 51-year-old female, were referred for cover for their distal leg defects from the Orthopedics and trauma Unit. All patients were operated on under spinal anaesthesia. Perforators from posterior tibial and peroneal arteries respectively, were identified pre-operatively with hand-held doppler and the propeller-pattern skin paddle was designed around the perforator closest to defect. After elevation of flaps and skeletonization of perforators, they were then rotated (180 degrees) and inset into defects. Case 1 had whole flap (104 cm2) surviving with only minor marginal epidemiolysis at tip whilst the second flap (58.5cm2) had necrosis of only the business end of the flap but subsequently healed by secondary intention after serial dressings. Both had secondary defects proximally after the rotation, which were skin grafted with 100% take. Conclusion: Propeller flap in our experience, is a feasible versatile option for reconstruction of soft tissue defects in the distal third of the leg.

Study of Various Modalities of Management of Lower One-third Leg Defects in a Tertiary Care Hospital

Background: Lower extremity reconstruction is essential to plastic surgery and focuses on treating wounds and defects secondary to trauma, cancer, or chronic disease processes. Anatomical features of the lower third of the leg like subcutaneous bone surrounded by tendons with no muscles and vessels in isolated compartments with little intercommunication between them make the coverage of the wounds in the region a challenging problem. Aim: to study the various modalities of surgical management of lower 1/3rd leg defects. The study also aims to study the defect size and region in planning various flaps possible in the reconstruction ladder. Methods: The study was conducted from September 2014 to June 2017 on patients admitted to the Department of Burns, Plastic &amp; Reconstructive Surgery and referred patients from the Department of General Surgery &amp; Orthopaedic Surgery, S C B Medical College &amp; Hospital, Cuttack. The Study includes all lower 3rd Leg defect varieties for different surgical treatment modalities. Results: Various reconstructive methods were used to cover the lower 1/3rdleg defects; the maximum was the free muscle transfer in 9 cases. The following typical flap used was the reverse sural flap. Conclusion: The goal in lower limb reconstruction involves needing a stable skeleton, allowing weight-bearing status, with adequate soft tissue coverage to nourish and protect the underlying bone. What one would use for reconstruction depends upon the surgeon’s familiarity and comfort levels with the technique as much as the various circumstances.

CRISPR/Cas9-Mediated Mutagenesis of Antennapedia in Spodoptera frugiperda.

The homeotic gene Antennapedia (Antp) has been identified as playing a pivotal role in the morphogenesis of the thorax and wings across various insect species. Leveraging insights from previous studies, the functional characterization of Antp in S. frugiperda was undertaken using RT-qPCR and the CRISPR/Cas9 genome-editing system. Phylogenetic analyses indicate that Antp shares a high degree of sequence homology among Lepidoptera species. The expression profile of SfAntp was detected by RT-qPCR. The results showed that SfAntp was expressed in the whole growth cycle of S. frugiperda, the expression level was the highest in the egg stage, and the expression level was higher from 12 h to 48 h. Tissue-specific expression profiling demonstrated that SfAntp was most abundantly expressed in the thoracic segments and legs. To functionally disrupt SfAntp, two sgRNA sites were designed at the first exon of SfAntp and the gene was knocked out by CRISPR/Cas9 via microinjection. The results showed that the deletion of SfAntp produced a mutant phenotype of thoracic fusion, thoracic leg defect, leg-like protrusions between the head and thoracic segments and pupation deformity. In addition, deletion of SfAntp resulted in high embryo mortality. Through DNA sequencing, it was found that the target site of the SfAntp mutant had different degrees of frameshift mutations, indicating that the mutant phenotype was indeed caused by the knockout of SfAntp.

Revascularization Prior to Defect Reconstruction of the Lower Limb - Essential Cooperation between Plastic and Vascular Surgery

Treatment of complex ischemic lower leg defects with exposure of deep anatomic structures represents a considerable challenge to involved specialties. In selected patients, limb salvage can be achieved as an alternative to major amputation by means of a combined approach including arterial reconstruction and subsequent free flap transfer. Arterial reconstruction can be performed either by endovascular or open surgical treatment (bypass reconstruction or implantation of an arteriovenous loop) preliminary to defect reconstruction using microsurgical free flap transplantation. Whereas the aim of the arterial reconstruction comprises the establishment of sufficient perfusion and creation of adequate target vessels for the free flap transfer, the selection of the appropriate flap entity depends on the extent of the wound as wells as on the presence of osteomyelitis. Arterial reconstruction and defect reconstruction can be performed as one-stage or two-stage procedure and has become an established and feasible treatment approach in centers. Evaluation of microperfusion by means of indocyanine green can further increase safety and feasibility of this method. Against this background, combined arterial reconstruction and subsequent free flap transfer provides excellent results in terms of amputation free survival and postoperative mobility. Essential is however an individualized decision making in consideration of patient selection and possible contraindications. This approach may be evaluated in mobile patients with complex wounds prior to major amputation.

Finding Predictors of Leg Defects in Pigs Using CNV-GWAS.

One of the most important areas of modern genome research is the search for meaningful relationships between genetic variants and phenotypes. In the livestock field, there has been research demonstrating the influence of copy number variants (CNVs) on phenotypic variation. Despite the wide range in the number and size of detected CNVs, a significant proportion differ between breeds and their functional effects are underestimated in the pig industry. In this work, we focused on the problem of leg defects in pigs (lumps/growths in the area of the hock joint on the hind legs) and focused on searching for molecular genetic predictors associated with this trait for the selection of breeding stock. The study was conducted on Large White pigs using three CNV calling tools (PennCNV, QuantiSNP and R-GADA) and the CNVRanger association analysis tool (CNV-GWAS). As a result, the analysis identified three candidate CNVRs associated with the formation of limb defects. Subsequent functional analysis suggested that all identified CNVs may act as potential predictors of the hock joint phenotype of pigs. It should be noted that the results obtained indicate that all significant regions are localized in genes (CTH, SRSF11, MAN1A1 and LPIN1) responsible for the metabolism of amino acids, fatty acids, glycerolipids and glycerophospholipids, thereby related to the immune response, liver functions, content intramuscular fat and animal fatness. These results are consistent with previously published studies, according to which a predisposition to the formation of leg defects can be realized through genetic variants associated with the functions of the liver, kidneys and hematological characteristics.