Acrofacial dysostosis Nager Syndrome is probably not a single disorder but rather a group of disorders which all affect the development of the jaws, external ears and limbs. The milder type affects the face and ears in a similar to Treacher Collins Syndrome with an under developed lower jaw and small external ears. In some children this can lead to feeding and breathing difficulties.
Intelligence is usually normal.
The severe types are likely to be due to different gene abnormalities. Most babies do not survive. The facial abnormalities are very severe and there is a shortening of all four limbs with digits missing. Most cases are sporadic but there are well documented cases of parent to child transmission indicating autosomal dominant inheritance. There may be autosomal recessive types as well.