Pathological Fracture of Femoral Neck Leading to a Diagnosis of Wilson's Disease: A Case Report and Review of Literature

MRSL: a causal network pruning algorithm based on GWAS summary data

Causal discovery is a powerful tool to disclose underlying structures by analyzing purely observational data. Genetic variants can provide useful complementary information for structure learning. Recently, Mendelian randomization (MR) studies have provided abundant marginal causal relationships of traits. Here, we propose a causal network pruning algorithm MRSL (MR-based structure learning algorithm) based on these marginal causal relationships. MRSL combines the graph theory with multivariable MR to learn the conditional causal structure using only genome-wide association analyses (GWAS) summary statistics. Specifically, MRSL utilizes topological sorting to improve the precision of structure learning. It proposes MR-separation instead of d-separation and three candidates of sufficient separating set for MR-separation. The results of simulations revealed that MRSL had up to 2-fold higher F1 score and 100 times faster computing time than other eight competitive methods. Furthermore, we applied MRSL to 26 biomarkers and 44 International Classification of Diseases 10 (ICD10)-defined diseases using GWAS summary data from UK Biobank. The results cover most of the expected causal links that have biological interpretations and several new links supported by clinical case reports or previous observational literatures.

Orthopaedic Manifestations of Inborn Errors of Metabolism

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Inborn errors of metabolism are disorders of carbohydrate, amino acid, organic acid, or purine and pyrimidine metabolism; disorders of fatty acid oxidation; disorders of metal metabolism; and lysosomal storage defects that can cause metabolic derangements that have secondary musculoskeletal effects.

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Orthopaedic surgeons should be aware that patients with inborn errors of metabolism may be at high risk for spasticity, which may cause joint subluxations, scoliosis, and contractures, as well as poor bone quality, which is caused by malnutrition or disordered bone growth.

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Multidisciplinary care and follow-up are important to identify musculoskeletal problems in a timely manner in order to provide effective treatment.

Long-Term Accumulation of Metals in the Skeleton as Related to Osteoporotic Derangements

The concentrations of metals in the environment are still not within the recommended limits as set by the regulatory authorities in various countries because of human activities. They can enter the food chain and bioaccumulate in soft and hard tissues/organs, often with a long half-life of the metal in the body. Metal exposure has a negative impact on bone health and may result in osteoporosis and increased fracture risk depending on concentration and duration of metal exposure and metal species. Bones are a long-term repository for lead and some other metals, and may approximately contain 90% of the total body burden in birds and mammals. The present review focuses on the most common metals found in contaminated areas (mercury, cadmium, lead, nickel, chromium, iron, and aluminum) and their effects on bone tissue, considering the possibility of the long-term bone accumulation, and also some differences that might exist between different age groups in the whole population.

Case Report: The Association of Wilson Disease in a Patient With Ataxia and GLUT-1 Deficiency

Background: Wilson disease (WD) and glucose transporter type 1 (GLUT1) deficiency syndrome are two syndromes with different modes of inheritance but share certain similarities on neurological presentation. To date we have not found previous reports of an association between these two disorders. Case Presentation: Here we describe a 9-year-old male with global developmental delay that presented with intermittent and sudden onset weakness that first occurred at age 3. He was diagnosed with a mutation in the SLC2A1 (Solute Carrier Family 2 Member 1) gene, which results in GLUT1 deficiency. A ketogenic diet could not be started because of unexplained elevated liver enzymes. Due to his liver enzymes' persistent elevation, further investigations demonstrated mildly decreased ceruloplasmin levels, high basal 24-h urinary copper excretion, and an elevated hepatic parenchymal copper concentration on liver biopsy, consistent with WD. Genetic testing revealed two separate mutations in the ATP7B (ATPase Copper Transporting Beta) gene, consistent with WD. The patient was treated with a low copper diet, zinc acetate, and trientine hydrochloride. When liver enzymes normalized, he was subsequently started on a ketogenic diet with improvement in neurological symptoms. His neurological symptoms were most likely secondary to GLUT1 deficiency syndrome, as WD's neurological symptoms are primarily observed in the second decade of life. Conclusion: Recent studies have demonstrated the importance of genetic testing upon unexplained persistent elevation of liver enzymes. This case highlights the importance of carefully evaluating a patient with an unexplained liver disorder, even in the presence of primary neurological disease, as it can have significant therapeutic implications.

A rare case of multiple and huge simple bone cysts in Wilson's disease

A simple bone cyst is a tumor-like lesion that is not a true neoplasm. It usually presents as a solitary lesion within the proximal humerus and proximal femur. The etiology of simple bone cysts is still to be elucidated. We describe our experience in the successful surgical management of a rare case of two, large-sized, simple bone cysts involving the entire left humerus and right femoral head, respectively, in a 34-year-old male patient with Wilson's disease and concomitant hepatic cirrhosis. We theorized that Wilson's disease could be the cause of the delay or blockage of the natural healing process of the simple long-bone cysts, leading to their abnormal growth and development. To our knowledge, such a combined occurrence of multiple, simple long-bone cysts and Wilson's disease has not been reported in the literature to date.