MONDO_0100558 (RNU4ATAC spectrum disorder) is a syndromic disease characterized by growth restriction, microcephaly, skeletal dysplasia, and cognitive impairment. Less common but variable findings include brain anomalies, seizures, strokes, immunodeficiency, and cardiac anomalies, as well as ophthalmologic, skin, renal, gastrointestinal, hearing, and endocrine involvement. The term includes Microcephalic osteodysplastic primordial dwarfism type I/III (MOPDI), Taybi-Linder syndrome, Lowry-Wood syndrome, and Roifman syndrome. Also known as: RNU4ATAC-related disorder, RNU4atac-opathy.