Special clinical manifestations and genetic characteristics of schaaf–Yang syndrome in Russian patients

A description of the clinical and genetic characteristics of four Russian patients with Schaaf–Yang syndrome, caused by previously described and newly identified nucleotide variants in MAGEL2 gene, is presented. It was shown that the most severe clinical manifestations were found in a patient with the new identified variant c.1828C>T (p.Gln610Ter), while in a patient with a new nucleotide variant c.1609C>T (p.Gln537Ter) the manifestations of the disease were moderate. Considering the significant similarity of the clinical manifestations of Schaaf–Yang syndrome with Prader–Willi syndrome, the criteria for their differential diagnosis are outlined, the use of which will help optimize the process of molecular genetic analysis aimed at finding the etiologic factor.