Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium. The phenotype is Macrocephaly (HP_0000256). Also known as: Increased size of cranium, Increased size of skull, Large head, Large head circumference, Macrocephalus, Macrocrania, Megacephaly.