A rare partial autosomal trisomy/tetrasomy characterised by facial dysmorphism (long thin face, prominent forehead, down-slanting palpebral fissures, prominent nose with broad nasal bridge, prominent chin), pre and postnatal overgrowth, renal anomalies (for example horseshoe kidney, renal agenesis, hydronephrosis), mild to severe learning difficulties and behavioural abnormalities. Additional features may include craniosynostosis and macrocephaly. [from SNOMEDCT_US]