title: Bridging markers defining the map position of X linked hypophosphataemic rickets.
abstract: Hypophosphataemic rickets is commonly an X linked dominant hereditary disorder associated with a renal tubular defect in phosphate transport and bone deformities. The gene causing this disorder has been mapped to Xp22.31----p21.3 by using cloned human X chromosome sequences identifying restriction fragment length polymorphisms (RFLPs) in linkage studies of affected families. The hypophosphataemic rickets gene locus (HPDR) was previously mapped distal to the X linked polymorphic locus DXS41 (99.6) but its position in relation to the distal loci DXS43 (D2) and DXS85 (782) was not established. In order to obtain a precise mapping of the disease locus in relation to these genetic loci, additional affected families informative for these X linked markers have been investigated. The combined results from the two studies have established linkage with the loci DXS41 (99.6) and DXS43 (D2); peak lod score for DXS41 (99.6) = 7.35, theta = 0.09, and peak lod score for DXS43 (D2) = 4.77, theta = 0.16. Multilocus linkage analysis mapped the hypophosphataemic rickets gene distal to the DXS41 (99.6) locus and proximal to the DXS43 (D2) locus, thereby revealing two bridging genetic markers for the disease.
authors.affiliation: Department of Medicine, Middlesex Hospital, London.
authors.forename: R V
authors.initials: RV
authors.lastname: Thakker
authors.forename: A P
authors.initials: AP
authors.lastname: Read
authors.forename: K E
authors.initials: KE
authors.lastname: Davies
authors.forename: M P
authors.initials: MP
authors.lastname: Whyte
authors.forename: R
authors.initials: R
authors.lastname: Weksberg
authors.forename: F
authors.initials: F
authors.lastname: Glorieux
authors.forename: M
authors.initials: M
authors.lastname: Davies
authors.forename: R C
authors.initials: RC
authors.lastname: Mountford
authors.forename: R
authors.initials: R
authors.lastname: Harris
authors.forename: A
authors.initials: A
authors.lastname: King
mesh_terms: D002874:Chromosome Mapping; D005260:Female; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D007015:Hypophosphatemia, Familial / Q000235:genetics*; D008297:Male; D009693:Nucleic Acid Hybridization; D010375:Pedigree; D014960:X Chromosome
chemical_list: D005819:Genetic Markers