title: Mosaic trisomy 9 and lobar holoprosencephaly.
abstract: The main features of trisomy 9 syndrome in mosaic and non-mosaic forms have been thoroughly described. Characteristic traits are low-set malformed ears, micrognathia, broad nose with bulbous tip, abnormal brain, congenital heart defects, abnormal hands and feet, genital abnormalities, and early death. We report a case of mosaic trisomy 9 with holoprosencephaly (HPE). The propositi was born at 37 weeks, with intra-uterine growth retardation, hypotelorism and single nostril, ventricular septal defect, anterior placement of anus, clenched hands with thumb adduction and ulnar deviation. Facial anomalies characteristic of trisomy 9 included deeply set eyes and short palpebral fissures, flat face with maxillary hypoplasia, small mouth, and low-set posteriorly angulated ears. Cytogenetic analysis showed mosaic trisomy 9 with 17% trisomic cells. Pathology confirmed lobar HPE. In literature, isolated arrhinia, related to the HPE spectrum, was reported in one case of mosaic trisomy 9. Our case raises the question of the causative role of trisomy 9 in full blown HPE.
authors.affiliation: Clinical Genetics, Neonatalogy, Centre Hospitalier Intercommunal, Créteil, France. marion.gerard@chicreteil.fr
authors.forename: Marion
authors.initials: M
authors.lastname: Gérard-Blanluet
authors.forename: Claude
authors.initials: C
authors.lastname: Danan
authors.forename: Martine
authors.initials: M
authors.lastname: Sinico
authors.forename: Françoise
authors.initials: F
authors.lastname: Lelong
authors.forename: Elsa
authors.initials: E
authors.lastname: Borghi
authors.forename: Gilles
authors.initials: G
authors.lastname: Dassieu
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Janaud
authors.forename: Sylvie
authors.initials: S
authors.lastname: Odent
authors.forename: Férechté
authors.initials: F
authors.lastname: Encha-Razavi
mesh_terms: D001921:Brain / Q000002:abnormalities; D002899:Chromosomes, Human, Pair 9; D005260:Female; D053823:Hedgehog Proteins; D016142:Holoprosencephaly / Q000209:etiology / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009030:Mosaicism; D000072079:Patched Receptors; D011956:Receptors, Cell Surface; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014314:Trisomy
chemical_list: D053823:Hedgehog Proteins; D008565:Membrane Proteins; D000072079:Patched Receptors; D011956:Receptors, Cell Surface; D015534:Trans-Activators