title: Origin of the supernumerary X chromosome in a patient with fragile X and Klinefelter syndrome.
abstract: We report on a 10-year-old patient with the fragile X [fra(X)] syndrome and a 47,XXY karyotype. He had Martin-Bell syndrome, including typical craniofacial findings and mental retardation. The fra(X) was detected on both X chromosomes of the patient in 8% of the metaphases examined. DNA analysis using X-chromosome sequences from the pericentromeric region and from distal Xq suggests that the patient is homozygous at the fra(X) locus due to maternal nondisjunction during meiosis II.
authors.affiliation: Division of Genetics, Children's Hospital, Boston, MA 02115.
authors.forename: K G
authors.initials: KG
authors.lastname: Kupke
authors.forename: A L
authors.initials: AL
authors.lastname: Soreng
authors.forename: U
authors.initials: U
authors.lastname: Müller
mesh_terms: D004247:DNA / Q000032:analysis; D015342:DNA Probes; D005260:Female; D005600:Fragile X Syndrome / Q000150:complications / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D007713:Klinefelter Syndrome / Q000150:complications / Q000235:genetics*; D008297:Male; D009630:Nondisjunction, Genetic; D010375:Pedigree; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D015342:DNA Probes; D005819:Genetic Markers; D004247:DNA