“…The etiology of OLHS is likely heterogeneous. Teratogenic drugs [Spivack and Bennett, 1968; Hall, 1971; Herrmann et al, 1976; Tuncbilek et al, 1977; Nevin et al, 1980; Bokesoy et al, 1983], intrauterine membranous strands [Torpin, 1968], vascular disruption [Lipson and Webster, 1993], chorionic villus sampling [Gruber and Burton, 1994], high maternal fever during gestation [Martínez‐Frías et al, 2001], and autosomal dominant [Temtamy and McKusick, 1969] as well as autosomal recessive [Dellagrammaticas et al, 1982] gene defects have been considered as causes of OLHS.…”