<unk>  is detectable from the fetal stage of development largely due to the distinctive consequences of holoprosencephaly, a spectrum of defects or malformations of the brain and face. Facial defects which may manifest in the eyes, nose, and upper lip, featuring cyclopia, anosmia, or in the growth of only a single central incisor, and severe overlapping of the bones of the skull. Cardiac and in some cases pulmonary deformities are present. Another signature deformity is bilateral polydactyly, and many patients also suffer from hypoplasia and genital deformities.
Young–Madders syndrome
Potocki–Lupski syndrome
Young's syndrome
Wilson–Turner syndrome
Fowler's syndrome
Lujan–Fryns syndrome
Wolcott–Rallison syndrome
Irvine–Gass syndrome