title: First trimester diagnosis of holoprosencephaly secondary to a ring chromosome 7.
abstract: Holoprosencephaly (HPE) is a developmental defect in humans in which the forebrain fails to completely separate into two hemispheres. We describe a 12 3/7-week-old fetus found on ultrasound evaluation to have features consistent with HPE, including a single anterior ventricle, fused thalami, and a flattened profile. Cytogenetic analysis of chorionic villi revealed a ring chromosome 7 [r(7)]. This uncommon finding has been associated with growth delay, microcephaly, and dermatologic abnormalities. However, both the clinical features and the extent of cytogenetic imbalance of chromosome 7 are variable, and few reported cases of r(7) have been molecularly studied. To our knowledge, this is the first report of a prenatally identified r(7), molecularly characterized using array comparative genomic hybridization.
authors.affiliation: Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
authors.forename: Lindsay B
authors.initials: LB
authors.lastname: Henderson
authors.forename: Virginia L
authors.initials: VL
authors.lastname: Corson
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Saul
authors.forename: Cynthia
authors.initials: C
authors.lastname: Anderson
authors.forename: Sarah
authors.initials: S
authors.lastname: Millard
authors.forename: Denise A S
authors.initials: DA
authors.lastname: Batista
authors.forename: Karin J
authors.initials: KJ
authors.lastname: Blakemore
authors.forename: Cheryl
authors.initials: C
authors.lastname: Descipio