Macrocephaly: as an isolated anomaly, is often familial, with autosomal dominant inheritance; may be a manifestation of other anomalies, including hydrocephalus and skeletal disorders such as achondroplasia

Microcephaly: can be familial, with autosomal dominant or recessive inheritance; may be associated with infections (viruses such as cytomegalovirus) and syndromes such as trisomy 13 and 18, Cornelia de Lange's, Rubinstein-Taybi, Prader-Willi, and fetal alcohol

Large fontanelles: may be associated with hypothyroidism, trisomy 13, 18, and 21 syndromes, and bone disorders such as cleidocranial dysostosis or hypophosphatasia