All individuals have global developmental delay and/or intellectual disability (ID). The majority (83%) have autism and almost all cases have behavioral difficulties. Examples included hand flapping, inappropriate laughter, easy excitability, hypersensitivity to sensory stimuli, anxiety, and emotional dysregulation.
Dysmorphisms were not consistently reported. One individual had microcephaly but all others were normocephalic. MRI findings were only available from 2 cases, one with hypopituitarism and one with asymmetric volume loss. The individuals with hypopituitarism also had cleft lip and palate. Seizures occurred in 2 (one third of cases). An equal number of males and females have been identified thus far with no sex-based differences in phenotype severity.
RFX4