title: A de novo translocation 46,X,t(X;15) causing haemophilia B in a girl: a case report.
abstract: Haemophilia B is an X-linked recessive bleeding disorder caused by mutations in the factor IX gene with an incidence of 1:25000-30000. Usually female carriers are clinically normal, and severe phenotypic expression of the disease in females is extremely rare. In this report we describe a girl with a clinically severe course of haemophilia B who had no signs of Turner syndrome or any other dysmorphic features. Cytogenetic and molecular studies in the patient and her parents showed a de novo translocation 46,X,t(X;15)(q27.1;p11.2) in the patient, indicating a possible break near the factor IX gene. The structurally normal X chromosome was late replicating and inactivated in all metaphases as shown by high-resolution R-banding. By fluorescence in situ hybridization (FISH) with YAC and cosmid probes we could further characterize the breakpoint region on the X chromosome and the involvement of the factor IX gene.
authors.affiliation: Ernst-Moritz-Arndt University, Institute for Human Genetics, Greifswald, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Schröder
authors.forename: M
authors.initials: M
authors.lastname: Poetsch
authors.forename: H
authors.initials: H
authors.lastname: Gazda
authors.forename: W
authors.initials: W
authors.lastname: Werner
authors.forename: T
authors.initials: T
authors.lastname: Reichelt
authors.forename: W
authors.initials: W
authors.lastname: Knoll
authors.forename: R
authors.initials: R
authors.lastname: Rokicka-Milewska
authors.forename: B
authors.initials: B
authors.lastname: Zieleniewska
authors.forename: F H
authors.initials: FH
authors.lastname: Herrmann
mesh_terms: D000328:Adult; D001777:Blood Coagulation; D015139:Blotting, Southern; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D004303:Dosage Compensation, Genetic; D005091:Exons; D005164:Factor IX / Q000235:genetics; D005260:Female; D002836:Hemophilia B / Q000097:blood / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D010375:Pedigree; D014178:Translocation, Genetic; D014960:X Chromosome / Q000235:genetics*
chemical_list: D005164:Factor IX