Congenital disorders of glycosylation (CDG) are a group of rare metabolic disorders caused by the defects in the glycosylation pathways of biomacromolecules leading to altered glycoprofiles in affected individuals. In this case study, we present a 3-year-old Slovak male patient with developmental delay, hearing impairment, epilepsy, microcephaly, facial dysmorphism, corpus callosum dysgenesis, and cardiac abnormalities.