Mosaic trisomy 9 and lobar holoprosencephaly.
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.
Gérard-Blanluet
Marion
M
Clinical Genetics, Neonatalogy, Centre Hospitalier Intercommunal, Créteil, France. marion.gerard@chicreteil.fr
Danan
Claude
C
Sinico
Martine
M
Lelong
Françoise
F
Borghi
Elsa
E
Dassieu
Gilles
G
Janaud
Jean-Claude
JC
Odent
Sylvie
S
Encha-Razavi
Férechté
F
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
D053823:Hedgehog Proteins; D008565:Membrane Proteins; D000072079:Patched Receptors; D011956:Receptors, Cell Surface; D015534:Trans-Activators