Molecular results confirmed that both had a double diagnosis involving the OCA2 gene, patient 13 with two additional variants in the CACNA1B gene responsible for an NDD with seizures and nonepileptic hyperkinetic movements, and patient 14 with Angelman syndrome due to a paternal isodisomy of chromosome 15 carrying a heterozygous 142.2 kb duplication comprising exons 3 to 19 of the OCA2 gene. Here, OCA2 is linked to Angelman syndrome.