Mitral Regurgitation and Heart Failure as the First Presentation in a Patient with Features of Two Connective Tissue Disorders: A Rare Combination of Mucopolysaccharidosis and Osteogenesis Imperfecta?

Osteogenesis Imperfecta: Skeletal and Non-skeletal Challenges in Adulthood

Osteogenesis imperfecta (OI) is a Mendelian connective tissue disorder associated with increased bone fragility and other clinical manifestations most commonly due to abnormalities in production, structure, or post-translational modification of type I collagen. Until recently, most research in OI has focused on the pediatric population and much less attention has been directed at the effects of OI in the adult population. This is a narrative review of the literature focusing on the skeletal as well as non-skeletal manifestations in adults with OI that may affect the aging individual. We found evidence to suggest that OI is a systemic disease which involves not only the skeleton, but also the cardiopulmonary and gastrointestinal system, soft tissues, tendons, muscle, and joints, hearing, eyesight, dental health, and women's health in OI and potentially adds negative affect to health-related quality of life. We aim to guide clinicians as well as draw attention to obvious knowledge gaps and the need for further research in adult OI.

Impaired ion homeostasis as a possible associate factor in mucopolysaccharidosis pathogenesis: transcriptomic, cellular and animal studies

Mucopolysaccharidoses (MPS) are a group of diseases caused by mutations resulting in deficiencies of lysosomal enzymes which lead to the accumulation of partially undegraded glycosaminoglycans (GAG). This phenomenon causes severe and chronic disturbances in the functioning of the organism, and leads to premature death. The metabolic defects affect also functions of the brain in most MPS types (except types IV, VI, and IX). The variety of symptoms, as well as the ineffectiveness of GAG-lowering therapies, question the early theory that GAG storage is the only cause of these diseases. As disorders of ion homeostasis increasingly turn out to be co-causes of the pathogenesis of various human diseases, the aim of this work was to determine the perturbations related to the maintenance of the ion balance at both the transcriptome and cellular levels in MPS. Transcriptomic studies, performed with fibroblasts derived from patients with all types/subtypes of MPS, showed extensive changes in the expression of genes involved in processes related to ion binding, transport and homeostasis. Detailed analysis of these data indicated specific changes in the expression of genes coding for proteins participating in the metabolism of Ca2+, Fe2+ and Zn2+. The results of tests carried out with the mouse MPS I model (Idua-/-) showed reductions in concentrations of these 3 ions in the liver and spleen. The results of these studies indicate for the first time ionic concentration disorders as possible factors influencing the course of MPS and show them as hypothetical, additional therapeutic targets for this rare disease.

Lumbar Scheuermann's disease found in a patient with osteogenesis imperfecta (OI) caused by a heterozygous mutation in COL1A2 (c.4048G > A): a case report

Background

Osteogenesis imperfecta (OI) is a heterogeneous connective tissue disorder characterized by increased bone fragility and a series of extraskeletal manifestations. Approximately 90 % of OI cases are caused by type I collagen variants encoded by the collagen type I alpha 1 (COL1A1) or type I alpha 2 (COL1A2) gene. Lumbar Scheuermann’s disease is an atypical type of Scheuermann’s disease accompanied by Schmorl’s nodes and irregular endplates but without pronounced kyphosis. Although the etiology of Scheuermann’s disease is unclear, genetic and environmental factors are likely.

Case presentation

Here, we report a 32-year-old male patient who experienced multiple brittle fractures. Gene sequencing revealed a heterozygous mutation, c.4048G > A (p.G1350S), in the COL1A2 gene, and the patient was diagnosed with OI. Magnetic resonance imaging of his thoracolumbar spine revealed multiple Schmorl’s nodes.

Conclusions

This is the first reported case of OI coexisting with the spinal presentation of Scheuermann’s disease. It is speculated that the COL1A2 gene mutation might be an underlying novel genetic cause of Scheuermann’s disease. In conclusion, this case demonstrates the relationship between Scheuermann’s disease and OI for the first time and enriches the genotype-phenotype spectrum of OI.