The inv dup sSMC found in the present case resulted in a shared tetrasomy of the NDN, SNRPN, and UBE3A genes, and trisomy of CHRFAM7A and CHRNA7 genes associated with DD, and poor speech; both are clinical manifestations reported in this patient (Chen et al., 2016; Chilakamarri and Mellin-, 2022). The gene discussed is SNRPN; the disease is dentin dysplasia.