title: Clinical and neuroradiological features of the 9p deletion syndrome.
abstract: BACKGROUND
  The 9p deletion syndrome is a rare condition, which associates trigonocephaly, facial dysmorphism and developmental delay. The neuroradiological aspects of this syndrome have not yet been described. The purpose of this article is to identify the clinical and neuroradiological features, that should be recognized by all specialists treating these children, for a proper and early diagnosis.
  
  
  METHODS
  Among patients with trigonocephaly treated at our institution, we retrospectively analyzed the clinical and neuroradiological aspects of children with genetically confirmed 9p deletion syndrome.
  
  
  RESULTS
  6 patients were identified. Beside trigonocephaly, the most frequent clinical findings were small ears, long philtrum, upslanting palpebral fissures, flat nasal bridge and variable psycho-motor delay. Hypertelorism was present in 4 of 6 patient, which is opposite to the hypotelorism typical of non-syndromic trigonocephaly. Among neuroradiological findings, large, anteriorly rotated sylvian cisterns and altered shape of the septum pellucidum were found in all patients, as well as the compression of the frontal cortex due to the metopic synostosis (MS). A thin or dysmorphic corpus callosum and a diffuse white matter hypoplasia were present in more than half of the cases. Futhermore we compared these MRI findings with those of a control group of 30 non-syndromic trigonocephalies.
  
  
  CONCLUSIONS
  Some recurrent neuroradiological alterations can be found in 9p deletion syndrome. The presence of these signs on MRI of a trigonocephalic patient should raise the suspicion of an underlying chromosomal alteration, such as the 9p deletion syndrome and prompt genetic investigations.
authors.affiliation: Department of Pediatric Neurosurgery, Craniofacial Unit, Necker Enfants Malades Hospital, 156 rue de Vaugirard, 75015, Paris, France.
authors.forename: Peter
authors.initials: P
authors.lastname: Spazzapan
authors.affiliation: Department of Pediatric Neurosurgery, Craniofacial Unit, Necker Enfants Malades Hospital, 156 rue de Vaugirard, 75015, Paris, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Arnaud
authors.affiliation: Department of Medical Genetics, Necker Enfants Malades Hospital, Paris, France.
authors.forename: Genevieve
authors.initials: G
authors.lastname: Baujat
authors.affiliation: Department of Genetics, Necker Enfants Malades Hospital, Paris, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Nizon
authors.affiliation: Department of Genetics, Necker Enfants Malades Hospital, Paris, France.
authors.forename: Valerie
authors.initials: V
authors.lastname: Malan
authors.affiliation: Department of Radiology, Necker Enfants Malades Hospital, Paris, France.
authors.forename: Francis
authors.initials: F
authors.lastname: Brunelle
authors.affiliation: Department of Pediatric Neurosurgery, Craniofacial Unit, Necker Enfants Malades Hospital, 156 rue de Vaugirard, 75015, Paris, France. federicodirocco@gmail.com.
authors.forename: Federico
authors.initials: F
authors.lastname: Di Rocco
mesh_terms: D061085:Agenesis of Corpus Callosum / Q000473:pathology*; D001921:Brain / Q000002:abnormalities* / Q000473:pathology; D016022:Case-Control Studies; D002872:Chromosome Deletion; D002899:Chromosomes, Human, Pair 9; D003337:Corpus Callosum / Q000473:pathology; D019465:Craniofacial Abnormalities / Q000473:pathology*; D003398:Craniosynostoses / Q000473:pathology*; D002658:Developmental Disabilities / Q000473:pathology*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D012189:Retrospective Studies; D012688:Septum Pellucidum / Q000002:abnormalities / Q000473:pathology; D066127:White Matter / Q000002:abnormalities / Q000473:pathology
keywords: Craniosynostosis; Magnetic resonance; Trigonocephaly