Denouement and Discussion
Amniotic Constriction Bands (Streeter Dysplasia, Ring Constrictions)
The major manifestation consists of ringlike constrictions that encircle a digit or limb. The constrictions may be deep and extend to the bone, resulting in swelling, vascular insufficiency, and gangrene. At birth, located at the site of the lesion, are small pieces of fibrous tissue or areas of black eschar. On close observation, adherent to the ring, thin shreds of tissue, which most likely represent amnion, can be seen. Amputations of varying severity take place in utero. Other limb abnormalities include syndactyly, brachydactyly, clubfeet, and nail dysplasia.Craniofacial abnormalities are usually present in the more severe cases and consist of cleft lip and palate, midline facial defects, microphthalmia, microcephaly, encephalocele, and skull defects. Mental retardation is present if the brain is affected.
Amniotic constriction bands do not seem to be inherited. The present theory concerning the cause is