title: Molecular characterization of a de novo ring chromosome 6 in a growth retarded but otherwise healthy woman.
abstract: The phenotype of patients with a ring chromosome 6 can be highly variable ranging from almost normal to severe malformations and mental retardation. Size and structure of the ring chromosome as well as the level of mosaicism are important factors for the clinical phenotype. Here, we report on a 25-year-old woman with short stature, minor scoliosis, normal fertility, appropriate psychomotor development, minor dysmorphisms, and a de novo ring chromosome 6. Conventional karyotyping as well as molecular cytogenetic and molecular investigations of DUSP22 on 6p and RP1-191N21.4 on 6q by a new technical approach indicated breakpoints less than 240 kb and less than 190 kb proximal to the telomeres of 6p and 6q, respectively. In addition, formation of the ring chromosome from the paternal chromosome was demonstrated. Thus this case clearly shows that in patients with ring chromosomes without loss of euchromatic material mitotic instability of the ring chromosome is the most important reason for growth retardation and minor congenital anomalies.
authors.affiliation: Division of Clinical Genetics, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Höckner
authors.forename: Barbara
authors.initials: B
authors.lastname: Utermann
authors.forename: Martin
authors.initials: M
authors.lastname: Erdel
authors.forename: Christine
authors.initials: C
authors.lastname: Fauth
authors.forename: Gerd
authors.initials: G
authors.lastname: Utermann
authors.forename: Dieter
authors.initials: D
authors.lastname: Kotzot
mesh_terms: D000328:Adult; D001483:Base Sequence; D002896:Chromosomes, Human, Pair 6; D017931:DNA Primers; D018392:Genomic Imprinting; D006130:Growth Disorders / Q000235:genetics*; D006801:Humans; D008297:Male; D012303:Ring Chromosomes
chemical_list: D017931:DNA Primers