Skeletal dysplasias: Approach to evaluation
- Carlos A Bacino, MD, FACMG
Carlos A Bacino, MD, FACMG
- Professor of Molecular and Human Genetics
- Baylor College of Medicine
The skeletal dysplasias are an extremely heterogeneous group of conditions that affect bone development. They encompass over 400 disorders . Most are the result of genetic defects. Skeletal dysplasias can present any time from the prenatal period to adult life. Forms with an early presentation may result in perinatal/neonatal death due to lung hypoplasia and respiratory complications. The estimated incidence of skeletal dysplasias is approximately 15.7 in 100,000 births.
The classification of these disorders and the understanding of their pathophysiology have improved over time due to the advent of molecular studies and gene discoveries. This knowledge has contributed to the development of treatment options for specific skeletal dysplasias, such as achondroplasia, hypophosphatasia, and osteogenesis imperfecta.
The evaluation of nonlethal skeletal dysplasias is discussed in this topic review. An overview of specific nonlethal skeletal dysplasias is reviewed separately. Prenatal diagnosis of the lethal skeletal dysplasias is covered in detail separately. (See "Approach to prenatal diagnosis of the lethal skeletal dysplasias".)
OVERVIEW OF SKELETAL DEVELOPMENT
Embryologically, bone development arises from two different processes :
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