Although microcephaly was not reported in any of the three brothers carrying the OGTC921Y variant (Omelková et al., 2023), it has been observed in individuals carrying other OGT-CDG variants including the OGT L254F, A259T and R284P variants (Gundogdu et al., 2018; Selvan et al., 2018; Willems et al., 2017). The gene discussed is OGT; the disease is microcephaly.