Clinical, radiographic, and morphologic studies of non-Majewski short rib-polydactyly cases show a spectrum of abnormalities. While the findings of Yang et al reported in this journal suggest that a unique change in chondrocytes, namely PAS-positive inclusions, might distinguish one group of patients from another, experience with 4 other cases with radiographic findings similar to the case reported by Yang and colleagues does not confirm the finding. Therefore, the full significance of their observation must await further morphologic studies of these patients. The clinical findings are extremely variable, and no feature is pathognomonic of either of the groups of patients. Similarly, the radiographic findings show a spectrum of severity. The original cases of Saldino and Noonan have a more severe ossification defect in the long bones and pelvis than any of these other cases. While genetic heterogeneity might be invoked to explain this wide spectrum of findings in these patients, at present, variability in expression in just as likely a hypothesis.