Understanding fetal factors that contribute to preterm birth: Sjögren-Larsson syndrome as a model.

Preterm birth is a hallmark of Sjögren-Larsson syndrome, presumably caused by the abnormal lipid metabolism of the fetus. At least five additional rare genetic disorders (namely Ehlers-Danlos syndrome, ichthyosis prematurity syndrome, congenital analbuminemia, osteogenesis imperfecta type II and restrictive dermopathy) were found in literature that lead to preterm birth of the affected fetus. These disorders are in fact "experiments of nature" and as such they shed new lights on the mechanisms causing preterm birth.