Related Experiment Video
Updated: Jun 16, 2025
Skeletal Phenotype Analysis of a Conditional Stat3 Deletion Mouse Model
Published on: July 3, 2020
Skeletal and Non-skeletal Phenotypes in Children with Osteogenesis Imperfecta
Juliana Marulanda1, Jean-Marc Retrouvey2, Frank Rauch3
1Shriners Hospital for Children - Canada, 1003 Decarie, Montreal, QC, H4A 0A9, Canada.
Insights
Osteogenesis imperfecta (OI) causes fractures and affects growth, muscle function, and craniofacial development. Understanding these OI phenotypes is crucial for future treatments.
Area of Science:
- Genetics
- Pediatrics
- Orthopedics
Background:
- Osteogenesis imperfecta (OI) is characterized by bone fragility and fractures.
- The OI phenotype extends beyond skeletal issues, impacting multiple tissues.
- Understanding the multifaceted nature of OI is essential for comprehensive patient care.
Purpose of the Study:
- To discuss key non-fracture phenotypes in osteogenesis imperfecta.
- To highlight skeletal growth and development, muscle weakness, and craniofacial characteristics in OI.
- To provide an overview of current knowledge on OI manifestations.
Main Methods:
- Literature review and synthesis of existing research on OI phenotypes.
- Discussion of direct and indirect effects contributing to OI manifestations.
- Analysis of OI type-specific growth curves and their clinical utility.
Main Results:
- Short stature is common in severe OI, influenced by genetic defects and skeletal deformities.
- Muscle weakness in OI can result from direct collagen abnormalities or indirect factors like immobility.
- Dental (dentinogenesis imperfecta) and craniofacial abnormalities are prevalent in severe OI.
Conclusions:
- OI presents with diverse phenotypes including growth impairment, muscle weakness, and craniofacial abnormalities.
- OI type-specific growth curves aid in assessing growth expectations.
- Future therapeutic strategies aim to address the broad spectrum of OI-related phenotypes.
Abstract:
Although fractures are the defining characteristic of osteogenesis imperfecta (OI), the disorder affects many tissues. Here we discuss three facets of the OI phenotype, skeletal growth and development, skeletal muscle weakness and the dental and craniofacial characteristics. Short stature is almost universal in the more severe forms of OI and is probably caused by a combination of direct effects of the underlying genetic defect on growth plates and indirect effects of fractures, bone deformities and scoliosis. Recent studies have developed OI type-specific growth curves, which allow determining whether a given child with OI grows as expected for OI type. Impaired muscle function is an important OI-related phenotype in severe OI. Muscles may be directly affected in OI by collagen type I abnormalities in muscle connective tissue and in the muscle-tendon unit. Indirect effects like bone deformities and lack of physical activity may also contribute to low muscle mass and function. Dental and craniofacial abnormalities are also very common in severe OI and include abnormal tooth structure (dentinogenesis imperfecta), malocclusion, and deformities in the bones of the face and the skull. It is hoped that future treatment approaches will address these OI-related phenotypes.
Related Concept Videos
01:20Introduction to the Skeletal System
Components of the Skeletal System
Bone, or osseous tissue, is a hard connective tissue that forms an internal support structure for the human body. Bones shield vulnerable organs and soft tissue from external forces. For example, the vertebral bones protect and support the spinal cord.
Cartilage, a semi-rigid connective tissue found in regions such as...
01:29Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
01:18Classification of Bones
Long and Short Bones
The appendicular skeleton, particularly the upper and lower limbs, is primarily made of long and short bones. The...
01:33Pleiotropy
01:29Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into ...
01:09Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...