title: [Absent or hypoplastic thymus: A marker for 22q11.2 microdeletion syndrome in case of polyhydramnios].
abstract: OBJECTIVE
  In prenatal diagnosis of 22q11.2 microdeletion syndrome, without cardiac malformation or multiple associated congenital anomalies, we study the presence of polyhydramnios and its association with thymic dysgenesis.
  
  
  METHODS
  This was a multicenter retrospective observational study. It was performed in two multidisciplinary centers for prenatal diagnosis in the south of France between January 1, 2010 and June 30, 2013. Inclusion criteria were prenatal diagnosis of 22q11.2 deletion syndrome. We excluded from the study any fetus with cardiac malformation or multiple associated congenital anomalies.
  
  
  RESULTS
  During the inclusion period, eleven antenatal diagnoses of 22q11.2 microdeletion syndrome have been made. Six cases were excluded: 5 fetuses with cardiac malformation and one with multiple associated congenital anomalies. Therefore, five cases of isolated polyhydramnios were included. All 5 fetuses had a thymic dysgenesis: 3 had a thymic agenesis and 1 thymic hypoplasia diagnosed by sonography and 1 had a thymic agenesis diagnosed by retrospective reading of fetal MRI.
  
  
  CONCLUSIONS
  When faced with a polyhydramnios, the presence of a thymic dysgenesis should be search for by ultrasound screening and would alert to the possibility of a 22q11.2 microdeletion syndrome. The confirmation of this is diagnosis by amniocentesis would enable improved antenatal support for parents and would enable early implementation of the multidisciplinary neonatal care that is required to avoid serious complications of this syndrome.
authors.affiliation: Service gynécologie obstétrique, CRHU Carémeau-Nîmes, place du Pr-Robert-Debré, 30029 Nîmes cedex 9, France. Electronic address: audrey_lamouroux@hotmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Lamouroux
authors.affiliation: Service gynécologie obstétrique, CRHU Carémeau-Nîmes, place du Pr-Robert-Debré, 30029 Nîmes cedex 9, France. Electronic address: eve.mousty@chu-nimes.fr.
authors.forename: E
authors.initials: E
authors.lastname: Mousty
authors.affiliation: Service d'imagerie pédiatrique, CRHU Arnaud-de-Villeneuve-Montpellier, 371, avenue du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France. Electronic address: o-prodhomme@chu-montpellier.fr.
authors.forename: O
authors.initials: O
authors.lastname: Prodhomme
authors.affiliation: Service de génétique clinique, CRHU Arnaud-de-Villeneuve-Montpellier, 371, avenue du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France. Electronic address: n-bigi@chu-montpellier.fr.
authors.forename: N
authors.initials: N
authors.lastname: Bigi
authors.affiliation: Service gynécologie obstétrique, CRHU Carémeau-Nîmes, place du Pr-Robert-Debré, 30029 Nîmes cedex 9, France.
authors.forename: M-P
authors.initials: MP
authors.lastname: Le Gac
authors.affiliation: Service gynécologie obstétrique, CRHU Carémeau-Nîmes, place du Pr-Robert-Debré, 30029 Nîmes cedex 9, France. Electronic address: vincent.letouzey@chu-nimes.fr.
authors.forename: V
authors.initials: V
authors.lastname: Letouzey
authors.affiliation: Service gynécologie obstétrique, CRHU Carémeau-Nîmes, place du Pr-Robert-Debré, 30029 Nîmes cedex 9, France. Electronic address: renaud.detayrac@chu-nimes.fr.
authors.forename: R
authors.initials: R
authors.lastname: De Tayrac
authors.affiliation: Service gynécologie obstétrique, CRHU Carémeau-Nîmes, place du Pr-Robert-Debré, 30029 Nîmes cedex 9, France. Electronic address: pierre.mares@chu-nimes.fr.
authors.forename: P
authors.initials: P
authors.lastname: Mares
mesh_terms: D000328:Adult; D004062:DiGeorge Syndrome / Q000175:diagnosis*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005602:France; D006801:Humans; D006831:Polyhydramnios / Q000175:diagnosis*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D013950:Thymus Gland / Q000002:abnormalities* / Q000000981:diagnostic imaging
keywords: 22q11 deletion syndrome; Antenatal ultrasound; Di George syndrome; Fetal thymus; Hydramnios; IRM fœtale; Microdélétion 22q11.2; Polyhydramnios; Syndrome de Di George; Thymus fœtal; prenatal MRI; Échographie anténatale