Delayed membranous cranial ossification in a mother and child.

We report on a girl and her mother with delayed intramembranous ossification of the cranial vault. The 11-month-old girl had a large ossification defect involving parietal bones, squamous portion of temporal bones, and interparietal region of occipital bone, while the mother showed a complete ossified cranial vault with flat posterior parietal region and prominent occiput. Both had a similar face characterized by frontal bossing, hypertelorism, downward slant of palpebral fissures, flat nasal bridge, and short midface. On reviewing the literature, we concluded that these cases may be a dominant transmitted ossification defect with characteristic face, different from the cranium bifidum-parietal foramina entity.