Monarch Disease Ontology entry MONDO_0010010 (Schinzel-Giedion syndrome) (SGS) is an ectodermal dysplasia syndrome chiefly characterized by a distinctive facial dysmorphism, hydronephrosis, severe developmental delay, typical skeletal malformations, and genital and cardiac anomalies. Also known as: SGS, Schinzel Giedion Syndrome, Schinzel-Giedion midface-retraction syndrome.