BackgroundAmnion Band Sequence (ABS) presents as congenital anomalies often presumed to be associated with amnion rupture, and includes malformations, deformations and disruptions. Anomalies range from simple constriction rings to lethal developmental defects. The most frequent defects include distal constriction rings, intrauterine amputations and acrosyndactyly.
Objective The intention of this project was to review the known or suggested aetiopathological and genetical mechanisms underlying ABS and to review the inheritance pattern. The main etiological theories of ABS are discussed in light of a case.
Material and methodsA literature search in PubMed and Embase, using the keywords amnion, band, syndrome, etiology, pathology and genetics. Articles were selected for including based on text and abstract. Additional articles were located via reference lists.
Results The aetiopathogenetical mechanisms which underly ABS have been debated for centuries. Currently there are three main theories: The exogenous theory of amnion bands and the endogenous theories of vascular disruption and embryonal dysplasia.
Discussion/ conclusionBased on literature available today, it is not possible to find a theory that fully explains the aetiopathogenesis of ABS. One of the theories may be correct, but it is also possible that there are multiple causes behind ABS. The theories don’t have to be mutually exclusive either. It is possible that the multiple anomalies seen with ABS in reality represent different conditions with different aetiologies.