title: Etiological heterogeneity and clinical characteristics of metopic synostosis: Evidence from a tertiary craniofacial unit.
abstract: Metopic synostosis (MS) accounts for approximately 10-15% of all craniosynostosis and is etiologically heterogeneous. This study aimed to examine the causes of MS, as observed in a tertiary craniofacial unit. We reviewed the case notes of 110 children with a diagnosis of MS, attending the craniofacial unit in Oxford between 1991 and 2008. Our results showed 38 children (38/110 or 34.6%) who had at least one additional structural abnormality or had a known syndromic diagnosis were classed as having syndromic MS. Chromosomal abnormalities were noted in 8/38 (21.4%) children: mosaic marker chromosome 2, 9p deletion (2/8), 11q deletion, 12pter deletion and duplication of 15q25 with other additional chromosomal abnormalities (3/8). Other syndromic diagnoses included Silver-Russell syndrome and Greig cephalopolysyndactyly. Prenatal exposure to sodium valproate (VPA) was noted in 8/110 children (7.8%), with the dose of the VPA being >or=1,000 mg/day in all cases. Other prenatal exposures reported in this study were: maternal diabetes (6/110), enoxaparin for hypercoagulable state (1/110), and thyroxine (1/110). The majority of patients (72/110 or 65.4%) had nonsyndromic MS. Speech delay was present in 11 children with nonsyndromic MS (11/72 or 15.3%) and 10 children with syndromic MS (10/38 or 26.3%). We conclude that approximately two-thirds of all MS is nonsyndromic. Prenatal exposure to VPA is a common cause of MS. Maternal diabetes, not previously linked to MS, was noted in 5.5% of cases. Chromosomal abnormalities account for about 6% of MS. An increased risk of speech delay is seen with both the syndromic and nonsyndromic forms.
authors.affiliation: Department of Clinical Genetics, The Churchill Hospital, Oxford, UK. usha.kini@orh.nhs.uk
authors.forename: Usha
authors.initials: U
authors.lastname: Kini
authors.forename: Jane A
authors.initials: JA
authors.lastname: Hurst
authors.forename: Jo C
authors.initials: JC
authors.lastname: Byren
authors.forename: Steven A
authors.initials: SA
authors.lastname: Wall
authors.forename: David
authors.initials: D
authors.lastname: Johnson
authors.forename: Andrew O M
authors.initials: AO
authors.lastname: Wilkie
mesh_terms: D000293:Adolescent; D000925:Anticoagulants / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D003398:Craniosynostoses / Q000139:chemically induced / Q000209:etiology* / Q000235:genetics; D017984:Enoxaparin / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011254:Pregnancy in Diabetics; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000175:diagnosis / Q000235:genetics; D013974:Thyroxine / Q000009:adverse effects; D014635:Valproic Acid / Q000009:adverse effects; D055815:Young Adult
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin; D014635:Valproic Acid; D013974:Thyroxine