In these 2 patients, an NGS panel for genes associated with MCDs and intellectual disability revealed the c.2737C>T (p.Arg913Cys) missense substitution (R913C) in the RR2 of the RELN gene (Figure 1B and Table 1), which they both inherited from their apparently healthy, but unexamined, mother. The gene discussed is RELN; the disease is Schmid metaphyseal chondrodysplasia.