title: Refining the locus of branchio-otic syndrome 2 (BOS2) to a 5.25 Mb locus on chromosome 1q31.3q32.1.
abstract: In 1991, a large family was described with an autosomal dominant inheritance of otological and branchial manifestations which was termed branchio-otic syndrome type 2 (BOS2). This trait was mapped by linkage analysis in this family to a region of 23-31 Mb on chromosome 1q25.1q32.1. In the present report we describe the clinical features of two patients with a deletion in this region: one patient has a deletion but no otological or branchial manifestations, the other patient manifests mild conductive hearing loss resulting from bilaterally malformed middle ear ossicles, as well as a preauricular pit. Mapping of the deletion breakpoints allowed to delineate the region involved in BOS2 to a 5.25 Mb region containing 27 protein-coding genes. A detailed medical history of both patients is provided and they are compared with the literature on other detected interstitial deletions of 1q25q32. These findings will aid in the identification of the genetic cause underlying BOS2.
authors.affiliation: Center for Human Genetics, University of Leuven, Leuven, Belgium.
authors.forename: Bernard
authors.initials: B
authors.lastname: Thienpont
authors.forename: Eftychia
authors.initials: E
authors.lastname: Dimitriadou
authors.forename: Katerina
authors.initials: K
authors.lastname: Theodoropoulos
authors.forename: Jeroen
authors.initials: J
authors.lastname: Breckpot
authors.forename: Helen
authors.initials: H
authors.lastname: Fryssira
authors.forename: Sophia
authors.initials: S
authors.lastname: Kitsiou-Tzeli
authors.forename: Meropi
authors.initials: M
authors.lastname: Tzoufi
authors.forename: Joris R
authors.initials: JR
authors.lastname: Vermeesch
authors.forename: Maria
authors.initials: M
authors.lastname: Syrrou
authors.forename: Koen
authors.initials: K
authors.lastname: Devriendt
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D000293:Adolescent; D001934:Branchial Region / Q000002:abnormalities*; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D004423:Ear / Q000002:abnormalities*; D006801:Humans; D007223:Infant; D008297:Male; D013577:Syndrome