We investigated 30 different mutations in 30 Egyptian children molecularly diagnosed with WES that mainly comprised 6 novel mutations and highlighted 3 rare neurodevelopmental diseases (Kaya-Barakat-Masson syndrome, classical infantile neuroaxonal dystrophy [INAD], and CLCN2-related leukoencephalopathy). The gene discussed is CLCN2; the disease is Kaya-Barakat-Masson syndrome.