May Be Caused by

 Common

Achondroplasia

Immobilized infant

Postural flattening

Trisomy 21

 Uncommon

Acrocephalosyndactyly Pfeiffer type

Acrocephalosyndactyly Saethre-Chotzen type

Acrodysostosis

Apert syndrome

Brachmann-de Lange syndrome

Carpenter syndrome

Crouzon syndrome

Sanfilippo syndrome

Weaver syndrome

Weill-Marchesani syndrome

XXXXY syndrome