The identification of a likely pathogenic variant in CACNA1C confirmed our suspicion of a “double diagnosis.” Table 1 compares the key clinical features of the patient (e.g., developmental delay [DD], IQ, behavioral issues, and facial features) with the typical features of KS alone and CACNA1C-related neurodevelopmental disorder based on Rodan et al. [7]. Here, CACNA1C is linked to dentin dysplasia.