Clinical and radiological distinction between spondylothoracic dysostosis (Lavy-Moseley syndrome) and spondylocostal dysostosis (Jarcho-Levin syndrome).

In 1938, Saul Jarcho and Paul Levin from Johns Hopkins Hospital reported cases of thoracic insufficiency due to vertebral and rib anomalies. Nearly 30 years later, in 1966, Norman Lavy and associates from Indiana University reported a similar syndrome in a family from Puerto Rico. Lavy's description was followed by a report by John E. Moseley from New York City, where the name spondylothoracic dysplasia (dysostosis) was first used. For more than half a century, there has been confusion regarding the distinction between these two phenotypically similar syndromes that cause thoracic insufficiency. Spondylocostal dysostosis (SCD), or Jarcho-Levin syndrome, causes mild to moderate respiratory insufficiency, is panethnic and has been linked to genes such as DLL3, which is known to be associated with the Notch pathway. In contrast, spondylothoracic dysostosis (STD), or Lavy-Moseley syndrome, results in more severe respiratory compromise, is largely linked to Puerto Rican cohorts and is thought to be associated to the MESP2 gene, also a Notch pathway gene. Long-term studies of Puerto Rican cohorts with STD contradicts the previously held belief that individuals affected with STD have markedly diminished life expectancy with as many as 25% surviving into later childhood and adult life.