C-Type Natriuretic Peptide and Achondroplasia

Achondroplasia and hypochondroplasia are the most common forms of dwarfism. Recent studies have shown that a small hormone called C-type natriuretic peptide (CNP) is an important regulator of linear growth. The investigators believe that genetic abnormality that causes achondroplasia and hypochondroplasia also disrupts CNP signaling, which may contribute to the growth problem. The investigators propose to look at levels of this and other closely related hormones in children and adults with achondroplasia or hypochondroplasia to see if they are different from levels in healthy people. The investigators hypothesis is that CNP levels are elevated in children with achondroplasia or hypochondroplasia, compared the healthy population. Another hypothesis is that CNP levels are not elevated in adults with achondroplasia or hypochondroplasia, since adults have no growth-plate cartilage. By studying the potential role of the CNP system in achondroplasia and hypochondroplasia, not only will the investigators provide further insight into the pathophysiology of these common syndromes, the investigators will also provide greater insight into the regulation of normal linear growth.