title: Brains and faces in holoprosencephaly: pre- and postnatal description of 30 cases.
abstract: OBJECTIVE
  To investigate the prenatal appearance of the holoprosencephaly spectrum.
  
  
  METHODS
  A database of 1750 fetuses with congenital anomalies identified by ultrasound was prospectively collected from 1987 to 2000. Among them, 30 cases (1.7%) with holoprosencephaly were prenatally identified and described.
  
  
  RESULTS
  The prevalence of holoprosencephaly in the Health Region of the National Center for Fetal Medicine in Norway was 1.26 : 10 000; the sex distribution (male : female) was 1.4 : 1. Holoprosencephaly was found in one dichorionic twin pregnancy and one pair of conjoined twins. Among the 30 cases of holoprosencephaly, 18 were alobar, five were semilobar, two were lobar, two were lobar variants, and three were anencephalic. The facial features varied considerably. Sixty-seven per cent (20/30) had associated structural anomalies that were not related to the cerebral and facial holoprosencephaly condition. Thirty-seven per cent (11/30) had detectable chromosome aberrations and 23% (7/30) had nonchromosomal syndromal origin. The size or shape of the head was abnormal in 83% (25/30) of holoprosencephaly cases.
  
  
  CONCLUSIONS
  This study indicates that holoprosencephaly represents a heterogeneous entity with different etiologies and clinical appearances. The fact that holoprosencephaly features are found associated with particular conditions such as fronto-nasal dysplasia (2/30; 6.7%), agnathia-otocephaly (3/30; 10%), and anencephaly (3/30; 10%), suggests that these may be underreported conditions in other large holoprosencephaly series.
authors.affiliation: National Center for Fetal Medicine, Department of Obstetrics and Gynecology, Trondheim University Hospital, Norway. harm-gerd.blaas@medisin.ntnu.no
authors.forename: H G K
authors.initials: HG
authors.lastname: Blaas
authors.forename: A G
authors.initials: AG
authors.lastname: Eriksson
authors.forename: K A
authors.initials: KA
authors.lastname: Salvesen
authors.forename: C V
authors.initials: CV
authors.lastname: Isaksen
authors.forename: B
authors.initials: B
authors.lastname: Christensen
authors.forename: G
authors.initials: G
authors.lastname: Møllerløkken
authors.forename: S H
authors.initials: SH
authors.lastname: Eik-Nes
mesh_terms: D000015:Abnormalities, Multiple; D000293:Adolescent; D000328:Adult; D005260:Female; D016142:Holoprosencephaly / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D006972:Hypertelorism / Q000000981:diagnostic imaging; D007621:Karyotyping; D008297:Male; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D016216:Ultrasonography, Prenatal