Abnormal ribs have been associated with congenital scoliosis in humans with skeletal dysplasias in skeletal pathology assessments as early as 1836 (Rokitansky, 1836; Nader and Sedivy, 2004); in the initial pudgy mouse description (Grüneberg, 1961); and in studies recognizing that mutations of the Dll3 gene of the Notch pathway cause the pudgy mouse malformations (Kusumi et al., 1998). This evidence concerns the gene DLL3 and skeletal dysplasia.