In conclusion, we provide a detailed phenotypic characterization of a biallelic ATP2B1 disorder, in a proband manifesting a distinctive neurodevelopmental, craniofacial, and skeletal phenotype, and persistent hypocalcemia secondary to primary hypoparathyroidism, discernible from other well-described syndromes (Supplementary Table S2). This evidence concerns the gene ATP2B1 and Hypocalcemia.