title: Should PMM2-deficiency (CDG Ia) be searched in every case of unexplained hydrops fetalis?
abstract: Hydrops fetalis (HF) is characterized by an accumulation of fluid in the extracellular compartments and in body cavities. Non-immune HF (NIHF) is caused by a wide variety of disorders and overall, 20-25% of NIHF remain unexplained. Inborn errors of metabolism, mostly lysosomal storage diseases have been estimated to account for 1-2% of cases, leading to HF by anemia or liver failure. Very few cases of NIHF and Congenital Disorder of Glycosylation (CDG) have been reported. We present here a case of recurrence of HF in a non-related couple in which the diagnosis of CDG type I was suspected at fetal pathological examination then confirmed at the enzymatic and molecular levels, as well as on a characteristic CDG I serum transferrin profile at 30weeks of gestation. We also provide a systematic review of reported cases with CDG type I and NIHF reported thus far. When NIHF remains unexplained despite exhaustive obstetrical screening, analysis of PMM activity in the parents' leucocytes is possible and might be performed easily during pregnancy. The accurate diagnosis is important in terms of counseling during pregnancy or later, in order to allow an early molecular prenatal diagnosis for the following pregnancies.
authors.affiliation: AP-HP, Hôpital Necker-Enfants Malades, Centre de médecine fœtale et Maternité de Necker-Brune, Paris, France.
authors.forename: Nadia
authors.initials: N
authors.lastname: Léticée
authors.forename: Bettina
authors.initials: B
authors.lastname: Bessières-Grattagliano
authors.forename: Thierry
authors.initials: T
authors.lastname: Dupré
authors.forename: Sandrine
authors.initials: S
authors.lastname: Vuillaumier-Barrot
authors.forename: Pascale
authors.initials: P
authors.lastname: de Lonlay
authors.forename: Ferechté
authors.initials: F
authors.lastname: Razavi
authors.forename: Nadia
authors.initials: N
authors.lastname: El Khartoufi
authors.forename: Yves
authors.initials: Y
authors.lastname: Ville
authors.forename: Michel
authors.initials: M
authors.lastname: Vekemans
authors.forename: Raymonde
authors.initials: R
authors.lastname: Bouvier
authors.forename: Nathalie
authors.initials: N
authors.lastname: Seta
authors.forename: Tania
authors.initials: T
authors.lastname: Attié-Bitach
mesh_terms: D018981:Congenital Disorders of Glycosylation / Q000175:diagnosis; D005260:Female; D006801:Humans; D015160:Hydrops Fetalis / Q000175:diagnosis* / Q000209:etiology; D016464:Lysosomal Storage Diseases / Q000150:complications; D017875:Phosphotransferases (Phosphomutases) / Q000172:deficiency*; D011247:Pregnancy
chemical_list: D017875:Phosphotransferases (Phosphomutases); C519582:phosphomannomutase 2, human