title: Tightly linked polymorphic markers for fragile X syndrome and prenatal cytogenetic diagnostic experience.
abstract: Linkage analysis using the polymorphic loci DXS369, DXS296, DXS297 and DXS306 was carried out on a cohort of 17 families segregating for fragile X syndrome. The observed recombination fractions at: DXS369 (Zmax = 3.02; theta = 0.06), DXS297 (Zmax = 2.92; theta = 0.0), DXS296 (Zmax = 3.82; theta = 0.0), DXA306 (Zmax = 4.55; theta = 0.05) confirm that these loci are tightly linked to FRAXA. Our experience in the cytogenetic analysis of 58 at risk pregnancies by chorionic villus or fetal blood sample examination documents a false negative rate in obligate carrier male pregnancies for CVS of 11% and for FBS of 3%.
authors.affiliation: Dept of Clinical Genetics, University of Birmingham.
authors.forename: I A
authors.initials: IA
authors.lastname: Glass
authors.forename: R G
authors.initials: RG
authors.lastname: Del Mastro
authors.forename: W G
authors.initials: WG
authors.lastname: Lanyon
authors.forename: J A
authors.initials: JA
authors.lastname: Raeburn
authors.forename: M W
authors.initials: MW
authors.lastname: Kilpatrick
authors.forename: T P
authors.initials: TP
authors.lastname: Webb
authors.forename: J M
authors.initials: JM
authors.lastname: Connor
mesh_terms: D003582:Cytogenetics; D004247:DNA / Q000235:genetics; D005260:Female; D005600:Fragile X Syndrome / Q000175:diagnosis / Q000235:genetics*; D006580:Genetic Carrier Screening; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011247:Pregnancy; D011296:Prenatal Diagnosis
chemical_list: D005819:Genetic Markers; D004247:DNA