Is Plasma C-Type Natriuretic Peptide Level Suitable for Diagnosing and Typing Skeletal Dysplasia?

Objective: Skeletal dysplasia is a heterogeneous group of diseases that lead to abnormal enchondral ossification and typing of the disease is quite complex. C-type natriuretic peptide (CNP), one of the members of the natriuretic peptide family, has been implicated in bone development, and CNP levels are high in some types of skeletal dysplasia. The aim of this study was to evaluate the use of CNP as a marker for skeletal dysplasia types and to investigate its role in typing.
Methods: Thirty-seven patients aged six months to 18 years [26 (70.3%) girls] were included in this cross-sectional study from among 75 skeletal dysplasia patients. All subjects were physically examined; anthropometric measurements were obtained, and bone surveys were evaluated. ELISA was used to assess CNP plasma levels. Forty-nine healthy children aged six months to 18 years [24 girls (49%)] comprised the control group.
Results: The CNP concentration of the patient group (n=37) was 1.31±1.40 ng/mL which was similar to the control group (n=49) at 1.04±1.40 ng/mL (p=0.207). However, the CNP concentration of patients with achondroplasia (n=17) was significantly higher (1.79±1.64 ng/mL) than the control group (p=0.032).
Conclusion: Our study contributes evidence concerning CNP values of both healthy children and children with skeletal dysplasia. Compared with healthy children, those with achondroplasia have elevated plasma levels of CNP. Further larger studies are necessary to assess the use CNP as a marker for the diagnosis and typing of skeletal dysplasia.