PhenoApt leverages clinical expertise to prioritize candidate genes via machine learning.

In recent years, exome sequencing (ES) has shown great utility in the diagnoses of Mendelian disorders. However, after rigorous filtering, a typical ES analysis still involves the interpretation of hundreds of variants, which greatly hinders the rapid identification of causative genes. Since the interpretations of ES data require comprehensive clinical analyses, taking clinical expertise into consideration can speed the molecular diagnoses of Mendelian disorders. To leverage clinical expertise to prioritize candidate genes, we developed PhenoApt, a phenotype-driven gene prioritization tool that allows users to assign a customized weight to each phenotype, via a machine-learning algorithm. Using the ability to rank causative genes in top-10 lists as an evaluation metric, baseline analysis demonstrated that PhenoApt outperformed previous phenotype-driven gene prioritization tools by a relative increase of 22.7%-140.0% in three independent, real-world, multi-center cohorts (cohort 1, n = 185; cohort 2, n = 784; and cohort 3, n = 208). Additional trials showed that, by adding weights to clinical indications, which should be explained by the causative gene, PhenoApt performance was improved by a relative increase of 37.3% in cohort 2 (n = 471) and 21.4% in cohort 3 (n = 208). Moreover, PhenoApt could assign an intrinsic weight to each phenotype based on the likelihood of its being a Mendelian trait using term frequency-inverse document frequency techniques. When clinical indications were assigned with intrinsic weights, PhenoApt performance was improved by a relative increase of 23.7% in cohort 2 and 15.5% in cohort 3. For the integration of PhenoApt into clinical practice, we developed a user-friendly website and a command-line tool.

Perturbations of genes essential for Müllerian duct and Wölffian duct development in Mayer-Rokitansky-Küster-Hauser syndrome.

Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) is associated with congenital absence of the uterus, cervix, and the upper part of the vagina; it is a sex-limited trait. Disrupted development of the Müllerian ducts (MD)/Wölffian ducts (WD) through multifactorial mechanisms has been proposed to underlie MRKHS. In this study, exome sequencing (ES) was performed on a Chinese discovery cohort (442 affected subjects and 941 female control subjects) and a replication MRKHS cohort (150 affected subjects of mixed ethnicity from North America, South America, and Europe). Phenotypic follow-up of the female reproductive system was performed on an additional cohort of PAX8-associated congenital hypothyroidism (CH) (n = 5, Chinese). By analyzing 19 candidate genes essential for MD/WD development, we identified 12 likely gene-disrupting (LGD) variants in 7 genes: PAX8 (n = 4), BMP4 (n = 2), BMP7 (n = 2), TBX6 (n = 1), HOXA10 (n = 1), EMX2 (n = 1), and WNT9B (n = 1), while LGD variants in these genes were not detected in control samples (p = 1.27E-06). Interestingly, a sex-limited penetrance with paternal inheritance was observed in multiple families. One additional PAX8 LGD variant from the replication cohort and two missense variants from both cohorts were revealed to cause loss-of-function of the protein. From the PAX8-associated CH cohort, we identified one individual presenting a syndromic condition characterized by CH and MRKHS (CH-MRKHS). Our study demonstrates the comprehensive utilization of knowledge from developmental biology toward elucidating genetic perturbations, i.e., rare pathogenic alleles involving the same loci, contributing to human birth defects.

Novel Modic grading scoring system and its clinical validation: a preliminary investigation.

PURPOSE: To propose a novel Modic grading scoring system and explore the relationship between the Modic grading score and disc degeneration, disc herniation, disc height, and clinical symptom scores. METHOD: In total, 194 patients were included in the study. The new Modic grading scoring system included four indicators: invaded vertebral height, invaded endplate length, endplate morphology, and grade of endplate defects. The severity of Modic changes was visually quantified by numerical scores, and the kappa value was used to verify the interobserver and intraobserver reliability. Spearman correlation analysis was used to explore the relationship between the Modic grading score and intervertebral disc degeneration, disc herniation, disc height, and clinical symptom scores. RESULTS: The interobserver and intraobserver reliability showed substantial to almost perfect agreement in the new Modic grading scoring system. The Modic grading score was positively correlated with intervertebral disc degeneration (r = 0.757, p < 0.001) and negatively correlated with the intervertebral disc height index (r = - 0.231, p < 0.001). There was no significant correlation between the Modic grading scoring system and disc herniation (r = 0.369, p = 0.249). Additionally, there was no significant correlation between the Modic grading score and the Japanese Orthopaedic Association score (r = - 0.349, p = 0.25), Oswestry Disability Index score (r = 0.246, p = 0.11), or visual analogue scale score (r = 0.315, p = 0.35). CONCLUSION: The new Modic grading scoring system had good interobserver and intraobserver reliability. The Modic grading score was positively correlated with intervertebral disc degeneration and negatively correlated with the intervertebral disc height.

Pentraxin 3 deficiency ameliorates the severity of osteoarthritis and alleviates inflammation.

BACKGROUND: Osteoarthritis is one of the most common degenerative joint disorders, characterized by articular cartilage breakdown, synovitis, osteophytes generation and subchondral bone sclerosis. Pentraxin 3 (PTX3) is a long pentraxin protein, secreted by immune cells, and PTX3 is identified to play a critical role in inflammation and macrophage polarization. However, the underlying mechanism of PTX3 in osteoarthritis under the circumstance of Ptx3-knockout (KO) mice model is still unknown. METHODS: Murine destabilization of the medial meniscus (DMM) OA model was created in Ptx3-knockout (KO) and wildtype mice, respectively. The degenerative status of cartilage was detected by Safranin O, H&E staining, immunohistochemistry (IHC) and micro-CT. OARSI scoring was employed to assess the proteoglycan of cartilage. Serum inflammatory cytokines were examined by ELISA and systematic macrophage polarization in spleen was analyzed by flow cytometry. RESULTS: Safranin O and H&E staining confirmed that the joint cartilage was mostly with reduced degeneration in both the senior KO mice and the DMM model generated from the KO mice, compared to the WT group. This is also supported by micro-CT examination and OARSI scoring. Immunohistochemistry illustrated an up-regulation of Aggrecan and Collagen 2 and down-regulation of ADAMTS-5 and MMP13 in KO mice in comparison with the WT mice. ELISA indicated a dramatical decrease in the serum levels of TNF-α and IL-6 in KO mice. Polarization of M2-like macrophages was observed in the KO group. CONCLUSION: Pentraxin 3 deficiency significantly ameliorated the severity of osteoarthritis by preventing cartilage degeneration and alleviated systematic inflammation by inducing M2 polarization.

Sacroiliac joint degeneration in degenerative lumbar spondylolisthesis and related risk factors: a retrospective study.

OBJECTIVE: This study was performed to evaluate the degree of radiological sacroiliac joint (SIJ) degeneration in patients with degenerative lumbar spondylolisthesis (DLS). The related risk factors for SIJ degeneration were also investigated. METHODS: We retrospectively analyzed the lumbar and pelvic computed tomography (CT) scans of 303 patients with DLS admitted from January 2018 to December 2021. One hundred and fifty-six age-, gender-, and body mass index-matched patients without lumbar anomality who underwent lower abdominal or pelvic computed tomography scans were included in the control group. Sagittal parameters were measured on full-length lateral radiographs. Two protocols (Backlund's grade and Eno's classification) were used to assess SIJ degeneration. Univariate analysis and bivariate and multivariate regression analysis were performed to identify the factors affecting SIJ degeneration in patients with DLS. RESULTS: According to Backlund's grade and Eno's classification, SIJ degeneration was more severe in the DLS group than in the control group (P < 0.001). Multi-segment degenerative changes (P = 0.032), two-level DLS (P = 0.033), a history of hysterectomy (P < 0.001), lower extremity pain (P = 0.016), and pelvic pain (P = 0.013) were associated with more significant SIJ degeneration as assessed by Backlund's grade. The results of Pearson's correlation analysis showed positive correlation between the sagittal vertical axis and SIJ degeneration (r = 0.232, P = 0.009). The multivariate linear regression analysis showed that a history of hysterectomy was significantly correlated with SIJ degeneration in patients with DLS (r = 1.951, P = 0.008). CONCLUSIONS: SIJ degeneration was more severe in patients with than without DLS. We should take SIJ degeneration into consideration when diagnosing and treating DLS especially those who had undergone previous hysterectomy or showed sagittal malalignment.

Safety and accuracy of cannulated pedicle screw placement in scoliosis surgery: a comparison of robotic-navigation, O-arm-based navigation, and freehand techniques.

PURPOSE: To compare the safety and accuracy of cannulated pedicle screw placement using a robotic-navigation technique, O-arm-based navigation technique, or freehand technique. METHODS: This study analyzed 106 consecutive patients who underwent scoliosis surgery. Thirty-two patients underwent robotic-navigation-assisted pedicle screw insertion (Group 1), 34 patients underwent O-arm-based navigation-guided pedicle screw insertion (Group 2), and 40 patients underwent freehand pedicle screw insertion (Group 3). The primary outcome measure was the accuracy of screw placement. Secondary outcome parameters included operation time, blood loss, radiation exposure, and postoperative stay. RESULTS: A total of 2035 cannulated pedicle screws were implanted in 106 patients. The accuracy rate of the first pedicle screw placement during operation was significantly greater in Group 1 (94.7%) than in Group 2 (89.2%; P < 0.001). The accuracy rate of pedicle screw placement postoperatively decreased in the order of Group 1 (96.7%) > Group 2 (93.0%) > Group 3 (80.4%; P < 0.01). There were no significant differences in blood loss or postoperative stay among the three groups (P > 0.05). The operation times of Group 1 and Group 2 were significantly longer than that of Group 3 (P < 0.05). CONCLUSION: The robotic-navigation and O-arm-based navigation techniques effectively increased the accuracy and safety of pedicle screw insertion alternative to the freehand technique in scoliosis surgery. Compared with the O-arm-based navigation technique, the robotic-navigation technique increases the mean operation time, but also increases the accuracy of pedicle screw placement. A three-dimensional scan after insertion of the K-wire may increase the accuracy of pedicle screw placement in the O-arm-based navigation technique.

Anterior cervical tunnectomy and fusion (ACTF): a novel technique for cervical canal decompression.

OBJECTIVE: To describe a novel surgical technique note coined as anterior cervical tunnectomy and fusion (ACTF) which applying on removal of posterior vertebral bony protrusions or soft extrusions. METHODS: Total twenty-three patients from January 2016 to January 2021 who experienced with spinal cord compression and performed by ACTF were retrospectively reviewed. Herein, relevant information including patient's gender, age, BMI, intraoperative time, intraoperative blood loss, postoperative complications and postoperative hospitalized stay were collected. Furthermore, JOA and VAS score were both collected. Moreover, imaging parameters were measured and calculated on radiographs. Correlated data were analyzed by t test. Significance was considered when P < 0.05. RESULTS: All patients in this study were validated with favorable outcomes and none of postoperative complications. The Nurick grade of patients dramatically deceased postoperation (P < 0.001). And postoperative VAS score of patients (P < 0.001), as well as JOA score (P < 0.001), was given dramatical significance comparing to preoperation. Furthermore, occupying rate (OR) (P < 0.001) was obviously reduced while space available cord (SAC) (P < 0.001) and diameter of spinal cord (P < 0.001) was significantly increased postoperation. Meanwhile, disc height of involved segment, C2-7 SVA, and C2-C7 Cobb angle were measured on sagittal plane of lateral radiograph. Postoperative disc height of involved segment (P < 0.001) significantly elevated comparing to preoperation. However, there were no significance on C2-7 SVA (P = 0.460) and C2-C7 Cobb angle (P = 0.097). CONCLUSIONS: The novel surgical technique coined by ACTF is a practicable approach during taking charge of bony and soft narrowing behind vertebral space.

Co-exposure to nanoplastics and acetaminophen causes skeletal dysplasia and behavioral abnormalities in zebrafish.

Nanoplastics (NPs) and acetaminophen (APAP) are thought to be common contaminants and are invariably detected in the environment. Despite the increasing awareness of their toxicity to humans and animals, the embryonic toxicity, skeletal development toxicity, and mechanism of action of their combined exposure have not been clarified. This study was performed to investigate whether combined exposure to NPs and APAP induces abnormal embryonic and skeletal development in zebrafish and to explore the potential toxicological mechanisms. All zebrafish juveniles in the high-concentration compound exposure group showed some abnormal phenomena such as pericardial edema, spinal curvature, cartilage developmental abnormality and melanin inhibition together with a significant downward trend in body length. Behavioral data also implicated that the exposure of APAP alone, as well as the co-exposure of NPs and APAP, caused a depression in the total distance, swimming speed and the maximum acceleration. Furthermore, real-time polymerase chain reaction analysis showed that compared with exposure alone, the expression level of genes related to osteogenesis, runx2a, runx2b, Sp7, bmp2b and shh was significantly reduced with compound exposure. These results suggest that the compound exposure of NPs and APAP has adverse impacts on zebrafish embryonic development and skeletal growth.

The utility of hierarchical genetic testing in paediatric liver disease.

BACKGROUND & AIMS: Genetic factors underlie a substantial proportion of paediatric liver diseases. Hereditary liver diseases have considerable genetic heterogeneity and variable clinical manifestations, which bring great challenges to clinical and molecular diagnoses. In this study, we investigated a group of paediatric patients with varying degrees of liver dysfunction using a hierarchical genetic testing strategy. METHODS: We first applied a panel encompassing 166 known causal genes of liver disease. We then used exome sequencing (ES) in those patients whose cases remained undiagnosed to identify the genetic aetiology of their symptoms. RESULTS: In total, we enrolled 131 unrelated paediatric patients with liver disease of Chinese Han ethnicity. We first applied targeted gene sequencing of 166 genes to all patients and yielded a diagnostic rate of 35.9% (47 of 131). Eighty-four patients who remained undiagnosed after target gene sequencing were subjected to ES. As a result, eight (8/84, 9.5%) of them obtained molecular diagnoses, including four patients suspected of abnormal bilirubin metabolism and four idiopathic cases. Non-typical genetic findings, including digenic inheritance and dual molecular diagnosis, were also identified. Through a comprehensive assessment of novel candidate variants of uncertain disease association, 11 patients of the remaining undiagnosed patients were able to obtain likely molecular diagnoses. CONCLUSIONS: Our study presents evidence for the diagnostic utility of sequential genetic testing in a cohort of patients with paediatric liver disease. Our findings expand the understanding of the phenotypic and mutational spectrum underlying this heterogeneous group of diseases.

Diagnostic yield and clinical impact of exome sequencing in early-onset scoliosis (EOS).

BACKGROUND: Early-onset scoliosis (EOS), defined by an onset age of scoliosis less than 10 years, conveys significant health risk to affected children. Identification of the molecular aetiology underlying patients with EOS could provide valuable information for both clinical management and prenatal screening. METHODS: In this study, we consecutively recruited a cohort of 447 Chinese patients with operative EOS. We performed exome sequencing (ES) screening on these individuals and their available family members (totaling 670 subjects). Another cohort of 13 patients with idiopathic early-onset scoliosis (IEOS) from the USA who underwent ES was also recruited. RESULTS: After ES data processing and variant interpretation, we detected molecular diagnostic variants in 92 out of 447 (20.6%) Chinese patients with EOS, including 8 patients with molecular confirmation of their clinical diagnosis and 84 patients with molecular diagnoses of previously unrecognised diseases underlying scoliosis. One out of 13 patients with IEOS from the US cohort was molecularly diagnosed. The age at presentation, the number of organ systems involved and the Cobb angle were the three top features predictive of a molecular diagnosis. CONCLUSION: ES enabled the molecular diagnosis/classification of patients with EOS. Specific clinical features/feature pairs are able to indicate the likelihood of gaining a molecular diagnosis through ES.

Increased TBX6 gene dosages induce congenital cervical vertebral malformations in humans and mice.

BACKGROUND: Congenital vertebral malformations (CVMs) manifest with abnormal vertebral morphology. Genetic factors have been implicated in CVM pathogenesis, but the underlying pathogenic mechanisms remain unclear in most subjects. We previously reported that the human 16p11.2 BP4-BP5 deletion and its associated TBX6 dosage reduction caused CVMs. We aim to investigate the reciprocal 16p11.2 BP4-BP5 duplication and its potential genetic contributions to CVMs. METHODS AND RESULTS: Patients who were found to carry the 16p11.2 BP4-BP5 duplication by chromosomal microarray analysis were retrospectively analysed for their vertebral phenotypes. The spinal assessments in seven duplication carriers showed that four (57%) presented characteristics of CVMs, supporting the contention that increased TBX6 dosage could induce CVMs. For further in vivo functional investigation in a model organism, we conducted genome editing of the upstream regulatory region of mouse Tbx6 using CRISPR-Cas9 and obtained three mouse mutant alleles (Tbx6up1 to Tbx6up3 ) with elevated expression levels of Tbx6. Luciferase reporter assays showed that the Tbx6up3 allele presented with the 160% expression level of that observed in the reference (+) allele. Therefore, the homozygous Tbx6up3/up3 mice could functionally mimic the TBX6 dosage of heterozygous carriers of 16p11.2 BP4-BP5 duplication (approximately 150%, ie, 3/2 gene dosage of the normal level). Remarkably, 60% of the Tbx6up3/up3 mice manifested with CVMs. Consistent with our observations in humans, the CVMs induced by increased Tbx6 dosage in mice mainly affected the cervical vertebrae. CONCLUSION: Our findings in humans and mice consistently support that an increased TBX6 dosage contributes to the risk of developing cervical CVMs.

Factors and predictive model associated with perioperative complications after long fusion in the treatment of adult non-degenerative scoliosis.

INTRODUCTION: Adult non-degenerative scoliosis accounts for 90% of spinal deformities in young adults. However, perioperative complications and related risk factors of long posterior instrumentation and fusion for the treatment of adult non-degenerative scoliosis have not been adequately studied. METHODS: We evaluated clinical and radiographical results from 146 patients with adult non-degenerative scoliosis who underwent long posterior instrumentation and fusion. Preoperative clinical data, intraoperative variables, and perioperative radiographic parameters were collected to analyze the risk factors for perioperative complications. Potential and independent risk factors for perioperative complications were evaluated by univariate analysis and logistic regression analysis. RESULTS: One hundred forty-six adult non-degenerative scoliosis patients were included in our study. There were 23 perioperative complications for 21 (14.4%) patients, eight of which were cardiopulmonary complications, two of which were infection, six of which were neurological complications, three of which were gastrointestinal complications, and four of which were incision-related complication. The independent risk factors for development of total perioperative complications included change in Cobb angle (odds ratio [OR] = 1.085, 95% CI = 1.035 ~ 1.137, P = 0.001) and spinal osteotomy (OR = 3.565, 95% CI = 1.039 ~ 12.236, P = 0.043). The independent risk factor for minor perioperative complications is change in Cobb angle (OR = 1.092, 95% CI = 1.023 ~ 1.165, P = 0.008). The independent risk factors for major perioperative complications are spinal osteotomy (OR = 4.475, 95% CI = 1.960 ~ 20.861, P = 0.036) and change in Cobb angle (OR = 1.106, 95% CI = 1.035 ~ 1.182, P = 0.003). CONCLUSIONS: Our study indicate that change in Cobb angle and spinal osteotomy are independent risk factors for total perioperative complications after long-segment posterior instrumentation and fusion in adult non-degenerative scoliosis patients. Change in Cobb angle is an independent risk factor for minor perioperative complications. Change in Cobb angle and spinal osteotomy are independent risk factors for major perioperative complications.

TBX6 missense variants expand the mutational spectrum in a non-Mendelian inheritance disease.

Congenital scoliosis (CS) is a birth defect with variable clinical and anatomical manifestations due to spinal malformation. The genetic etiology underlying about 10% of CS cases in the Chinese population is compound inheritance by which the gene dosage is reduced below that of haploinsufficiency. In this genetic model, the trait manifests as a result of the combined effect of a rare variant and common pathogenic variant allele at a locus. From exome sequencing (ES) data of 523 patients in Asia and two patients in Texas, we identified six TBX6 gene-disruptive variants from 11 unrelated CS patients via ES and in vitro functional testing. The in trans mild hypomorphic allele was identified in 10 of the 11 subjects; as anticipated these 10 shared a similar spinal deformity of hemivertebrae. The remaining case has a homozygous variant in TBX6 (c.418C>T) and presents a more severe spinal deformity phenotype. We found decreased transcriptional activity and abnormal cellular localization as the molecular mechanisms for TBX6 missense loss-of-function alleles. Expanding the mutational spectrum of TBX6 pathogenic alleles enabled an increased molecular diagnostic detection rate, provided further evidence for the gene dosage-dependent genetic model underlying CS, and refined clinical classification.

A novel COMP mutation in a Chinese family with multiple epiphyseal dysplasia.

BACKGROUND: Multiple epiphyseal dysplasia (MED) is a skeletal disorder characterized by delayed and irregular ossification of the epiphyses and early-onset osteoarthritis. At least 66% of the reported autosomal dominant MED (AD-MED) cases are caused by COMP mutations. METHODS: We recruited a four-generation Chinese family with early-onset hip osteoarthritis, flatfoot, brachydactyly, and mild short stature. An assessment of the family history, detailed physical examinations, and radiographic evaluations were performed on the proband and other family members, followed by the performance of whole-exome sequencing (WES). The pathogenicity of the candidate mutation was also analyzed. RESULTS: An AD-MED family with 10 affected members and 17 unaffected members was recruited. The main radiographic findings were symmetrical changes in the dysplastic acetabulum and femoral heads, irregular contours of the epiphyses, a shortened femoral neck, and flatfoot. Lower bone density was also observed in the ankle joints, wrist joints, and knees, as well as irregular vertebral end plates. In the proband, we identified the missense mutation c.1153G > T (p. Asp385Tyr), located in exon 11 of the COMP gene. This mutation was assessed as 'pathogenic' because of its low allele frequency and its high likelihood of co-segregation with disease in the reported family. Sanger sequencing validated the novel heterozygous mutation c.1153G > T (p. Asp385Tyr) in exon 11 of COMP in all affected individuals in the family. CONCLUSIONS: Our results underlined a key role of the Asp385 amino acid in the protein function of COMP and confirmed the pathogenicity of the COMP (c.1153G > T; p. Asp385Tyr) mutation in AD-MED disease. We have therefore expanded the known mutational spectrum of COMP and revealed new phenotypic information for AD-MED.

Identification of novel FBN1 variations implicated in congenital scoliosis.

Congenital scoliosis (CS) is a form of scoliosis caused by congenital vertebral malformations. Genetic predisposition has been demonstrated in CS. We previously reported that TBX6 loss-of-function causes CS in a compound heterozygous model; however, this model can explain only 10% of CS. Many monogenic and polygenic CS genes remain to be elucidated. In this study, we analyzed exome sequencing (ES) data of 615 Chinese CS from the Deciphering Disorders Involving Scoliosis and COmorbidities (DISCO) project. Cosegregation studies for 103 familial CS identified a novel heterozygous nonsense variant, c.2649G>A (p.Trp883Ter) in FBN1. The association between FBN1 and CS was then analyzed by extracting FBN1 variants from ES data of 574 sporadic CS and 828 controls; 30 novel variants were identified and prioritized for further analyses. A mutational burden test showed that the deleterious FBN1 variants were significantly enriched in CS subjects (OR = 3.9, P = 0.03 by Fisher's exact test). One missense variant, c.2613A>C (p.Leu871Phe) was recurrent in two unrelated CS subjects, and in vitro functional experiments for the variant suggest that FBN1 may contribute to CS by upregulating the transforming growth factor beta (TGF-ß) signaling. Our study expanded the phenotypic spectrum of FBN1, and provided nove insights into the genetic etiology of CS.

Estrogen Receptors (ESRs) Mutations in Adolescent Idiopathic Scoliosis: A Cross-Sectional Study.

BACKGROUND Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity, but its etiology is unclear. Multiple genetic mutations have been reported to be associated with AIS. MATERIAL AND METHODS We enrolled a cohort of 113 surgically treated AIS patients with available parental subjects from the Peking Union Medical College Hospital. We performed whole-exome sequencing in 10 trio families and whole-genome sequencing in 103 singleton patients. Luciferase assay was used to detect the functional alterations of candidate ESR1 and ESR2 variants. RESULTS Using a de novo strategy, a missense variant in ESR1 (c.868A>G) was selected as a candidate gene for AIS. The main Cobb angle of this patient was 41° (T6-T10). Another potential pathogenic variant in ESR2 (c.236T>C) was identified. The main curve of the patient was 45° at T10-L3. The transactivation capacities of the mutated ESR1 and ESR2 protein were both significantly decreased (p=0.026 and 0.014, respectively). CONCLUSIONS Potential pathogenic variants in ESR1 and ESR2 were identified in 113 AIS patients, suggesting that genetic mutations in ESR1/2 were associated with the risk of AIS.

The mutational burden and oligogenic inheritance in Klippel-Feil syndrome.

BACKGROUND: Klippel-Feil syndrome (KFS) represents a rare anomaly characterized by congenital fusion of the cervical vertebrae. The underlying molecular etiology remains largely unknown because of the genetic and phenotypic heterogeneity. METHODS: We consecutively recruited a Chinese cohort of 37 patients with KFS. The clinical manifestations and radiological assessments were analyzed and whole-exome sequencing (WES) was performed. Additionally, rare variants in KFS cases and controls were compared using genetic burden analysis. RESULTS: We primarily examined rare variants in five reported genes (GDF6, MEOX1, GDF3, MYO18B and RIPPLY2) associated with KFS and detected three variants of uncertain significance in MYO18B. Based on rare variant burden analysis of 96 candidate genes related to vertebral segmentation defects, we identified BAZ1B as having the highest probability of association with KFS, followed by FREM2, SUFU, VANGL1 and KMT2D. In addition, seven patients were proposed to show potential oligogenic inheritance involving more than one variants in candidate genes, the frequency of which was significantly higher than that in the in-house controls. CONCLUSIONS: Our study presents an exome-sequenced cohort and identifies five novel genes potentially associated with KFS, extending the spectrum of known mutations contributing to this syndrome. Furthermore, the genetic burden analysis provides further evidence for potential oligogenic inheritance of KFS.

Cervical sagittal alignment in adolescent idiopathic scoliosis patients (Lenke type 1-6).

OBJECTIVE: We collected the radiographic and clinical data of 129 AIS patients (Lenke type 1-6) to analyze the characteristics of cervical sagittal alignment in adolescent idiopathic scoliosis patients and the correlations between cervical sagittal alignment and global sagittal alignment, and clinical symptoms. METHODS: 129 patients with AIS and 48 adolescent volunteers were included in this study. The angles of the main thoracic curve, proximal thoracic curve, thoracolumbar curve, lumbar curve, C2-7 Cobb angle, T5-12 Cobb angle, L1-5 Cobb angle, pelvic incidence, pelvic tilt, sacrum slop, C2-7 sagittal vertical axis, C7-S1 sagittal vertical axis, and T1 pelvic angle were included in radiographic measurements. In addition, a 10-cm Visual Analogue Score was used to assess neck pain. Pearson correlation coefficients and t-test were used for statistical analysis. RESULTS: In the AIS group, C2-7 Cobb angle increased significantly compared with the control group, and it was significantly correlated with T5-12 Cobb angle and L1-5 Cobb angle. There was no significant correlation between C2-7 Cobb angle and coronal curvature in each Lenke type of patients. In the C2-7 SVA ≥ 3 cm group, C2-7 Cobb angle was related to T5-12 Cobb angle, L1-5 Cobb angle, pelvic incidence, and sacrum slop. In the cervical kyphosis group, T5-12 Cobb angle was significantly lower than that of the C2-7 Cobb angle ≥0 group. The C2-7 Cobb angle in the group with T5-12 Cobb angle >30° increased significantly compared with that in the group with T5-12 Cobb angle ≤30°. The Visual Analogue Score of neck pain of the cervical imbalance group was significantly higher than that of the cervical balance group. CONCLUSIONS: The cervical sagittal alignment in AIS patients was related with thoracic kyphosis and lumbar lordosis, especially with thoracic kyphosis, but not with the coronal angle of thoracic and lumbar spine, and pelvic parameters.

Impact of bilateral facet joint violation on radiographic degeneration of superior adjacent segments and clinical outcomes.

OBJECTIVE: Facet joint violation (FJV) is associated with postoperative low-back pain and is a confirmed risk factor for adjacent-segment degeneration, a long-term complication of lumbar fusion surgery. The authors' knowledge of its mechanisms comes from in vitro biomechanical research only; there is a lack of radiographic evidence of the effects of violation on the superior adjacent-segment facet joint, intervertebral disc, and other local radiographic parameters. Furthermore, any differences between unilateral and bilateral violation remain relatively unclear. The authors therefore aimed to explore the effects of nonviolation and unilateral and bilateral violation on radiographic degeneration of the facet joint and intervertebral disc at the fusion and superior adjacent segment. Patient-reported clinical outcomes were compared at the 2-year follow-up. METHODS: The authors retrospectively analyzed data from 148 patients with lumbar degenerative diseases who underwent single-segment minimally invasive transforaminal lumbar interbody fusion between 2016 and 2020. FJV and facet joint degeneration were evaluated and graded using Shah's method and Pathria's standard, respectively. Radiographic parameters, including disc height and intervertebral Cobb angle at the fusion and superior adjacent segment, were measured. Clinical outcomes were evaluated using visual analog scale (VAS) and Japanese Orthopaedic Association scores. RESULTS: Preoperative data were comparable among the 3 groups (nonviolation, unilateral violation, and bilateral violation) (p > 0.05). Patient-reported clinical outcomes were followed up for at least 2 years (average duration 28.17 ± 6.17 months). At the last follow-up, facet joint degeneration grades were sequentially increased in the nonviolation, unilateral violation, and bilateral violation groups (p = 0.006). The unilateral (2.45 ± 2.17 mm) and bilateral (2.70 ± 1.94 mm) violation groups had more severe losses of disc height in the superior adjacent segment than did the nonviolation group (1.31 ± 2.01 mm). The VAS low-back pain and Japanese Orthopaedic Association scores in the bilateral (2.57 ± 1.44 and 19.83 ± 2.84, respectively) and unilateral (2.26 ± 0.79 and 20.43 ± 3.85, respectively) violation groups were significantly worse than in the nonviolation group (1.69 ± 1.12 and 21.80 ± 3.36, respectively) (p < 0.05). By contrast, there were no significant between-group differences in disc height, intervertebral Cobb angle in the fusion segment, or VAS leg pain scores (p > 0.05). CONCLUSIONS: FJV was associated with postoperative low-back pain and worse functional outcomes. It also aggravated facet joint and intervertebral disc changes in the superior adjacent segment, especially when bilateral violation occurred; this may be part of the mechanisms of adjacent-segment degeneration.

Hysterectomy - a possible risk factor for operative intervention in female patients for degenerative lumbar spine conditions: a case control and cohort study.

BACKGROUND CONTEXT: Researchers have recently linked hysterectomy, which alters sex hormone levels, to diseases like osteoporosis, lumbar spondylolisthesis, hypertension and diabetes etc. However, the association between hysterectomy and lumbar disc herniation (LDH)/lumbar spinal stenosis (LSS) remains unclarified. PURPOSE: To determine whether there is a correlation between hysterectomy and surgical intervention for LDH/LSS in women, further substantiated through imaging and clinical research. STUDY DESIGN: A case control and cohort study. PATIENT SAMPLE: The study group comprised 1202 female patients aged 45 and older who had undergone operative treatment due to LDH/LSS (825 for LDH and 377 for LSS), and the comparison group comprised 1168 females without lumbar diseases who visited health examination clinic during the same period. One hundred and 2 hysterectomized patients were further selected (Hysterectomy cohort) and matched approximately with the control cohort at a 1:2 ratio from the study group with a minimum follow-up of 2 years. OUTCOME MEASURES: Odds Ratios (ORs) and 95% Confidence Intervals (CIs) were calculated to assess the association between hysterectomy and surgical intervention for LDH/LSS in women after adjusted by confounding factors. Patients from both the hysterectomy and control cohorts underwent a comprehensive assessment. This assessment included the evaluation of several parameters: the functional cross-sectional area, fat infiltration rate, relative functional cross-sectional area of the lumbar paravertebral muscles, facet joint degeneration grade, cartilage endplate damage, Modic changes for the L3/4-L5/S1 segments, Pfirrmann grade of lumbar disc degeneration, and disc height index for the L1/2-L5/S1 segments. Additionally, the Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) scores were recorded preoperatively and at the last follow-up. METHODS: Associations between hysterectomy and patients treated surgically for LDH or LSS were analyzed using multivariate binomial logistic regression analysis. Lumbar X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) were used to evaluate the imaging variables. Imaging and clinical variables were compared. RESULTS: Hysterectomized women were associated with requiring surgery due to LDH/LSS, with ORs of 2.613 (p<.001) and 2.084 (p=.006), respectively. The imaging evaluation further revealed that the hysterectomy cohort had more severe degeneration of the paraspinal muscles, facet joints, endplates, and intervertebral discs, Modic changes at L3/4-L5/S1 segments, and intervertebral height reduction at L1/2-L5/S1 segments when compared to the control cohort (p<.01). Compared to the control cohort, the hysterectomy cohort exhibited higher preoperative and last follow-up VAS scores for low back pain, and last follow-up JOA scores (p<.01). CONCLUSIONS: Based on the findings of this study, it seems that women who have had a hysterectomy are correlated with requiring surgical intervention due to LDH/LSS. Imaging and clinical studies also indicate that hysterectomized patients exhibited more severe lumbar degeneration and back pain.