Similarly, a heterozygous c.416C>T, p.(Pro139Leu) variant of CAMK2B found in four Caucasian patients presented with severe ID, global developmental delay, hypotonia and microcephaly (Küry et al., 2017), was also reported in a 22-year-old South Asian woman (Rizzi et al., 2020) as well as in a MECP-2 (methyl-CpG binding protein 2) negative proband of Japanese origin (Iwama et al., 2019). The gene discussed is MECP2; the disease is Global developmental delay.