title: Duplication 8q12: confirmation of a novel recognizable phenotype with duane retraction syndrome and developmental delay.
abstract: Duane retraction syndrome (DRS) is a rare congenital strabismus condition with genetic heterogeneity. DRS associated with intellectual disability or developmental delay is observed in several genetic diseases: syndromes such as Goldenhar or Wildervanck syndrome and chromosomal anomalies such as 12q12 deletion. We report on the case of a patient with DRS, developmental delay and particular facial features (horizontal and flared eyebrows, long and smooth philtrum, thin upper lip, full lower lip and full cheeks). We identified a duplication of the long arm of chromosome 8 (8q12) with SNP-array. This is the third case of a patient with common clinical features and 8q12 duplication described in the literature. The minimal critical region is 1.2 Mb and encompasses four genes: CA8, RAB2, RLBP1L1 and CHD7. To our knowledge, no information is available in the literature regarding pathological effects caused by to overexpression of these genes. However, loss of function of the CHD7 gene leads to CHARGE syndrome, suggesting a possible role of the overexpression of this gene in the phenotype observed in 8q12 duplication patients. We have observed that patients with 8q12 duplication share a common recognizable phenotype characterized by DRS, developmental delay and facial features. Such data combined to the literature strongly suggest that this entity may define a novel syndrome. We hypothesize that CHD7 duplication is responsible for a part of the features observed in 8q12.2 duplication.
authors.affiliation: Département de Pédiatrie spécialisée, Unité de Néphrologie et Endocrinologie pédiatrique, CHRU Montpellier, Faculté de Médecine de Montpellier-Nîmes, Université Montpellier 1, Montpellier, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Amouroux
authors.forename: Marie
authors.initials: M
authors.lastname: Vincent
authors.forename: Patricia
authors.initials: P
authors.lastname: Blanchet
authors.forename: Jacques
authors.initials: J
authors.lastname: Puechberty
authors.forename: Anouck
authors.initials: A
authors.lastname: Schneider
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Chaze
authors.forename: Manon
authors.initials: M
authors.lastname: Girard
authors.forename: Magali
authors.initials: M
authors.lastname: Tournaire
authors.forename: Christian
authors.initials: C
authors.lastname: Jorgensen
authors.forename: Denis
authors.initials: D
authors.lastname: Morin
authors.forename: Pierre
authors.initials: P
authors.lastname: Sarda
authors.forename: Geneviève
authors.initials: G
authors.lastname: Lefort
authors.forename: David
authors.initials: D
authors.lastname: Geneviève
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics; D002675:Child, Preschool; D058674:Chromosome Duplication; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D002658:Developmental Disabilities / Q000235:genetics*; D004370:Duane Retraction Syndrome / Q000235:genetics*; D006801:Humans; D008297:Male; D010641:Phenotype