In 2018, Jansen et al. described 23 patients with different heterozygous mutations in PHIP and associated them with a syndrome mainly characterized by DD, learning difficulties/ID, behavioral abnormalities, facial dysmorphism and obesity (Jansen et al., 2018), later termed Chung-Jansen syndrome (CHUJANS, OMIM #617991) or DIDOD (Developmental delay, Intellectual Disability, Obesity, and Dysmorphism). The gene discussed is PHIP; the disease is dentin dysplasia.