title: Turner syndrome mosaicism: an unusual case with a de novo large dicentric marker chromosome: mos 45,X/46,X, ter rea(X;X)(p22.3;p22.3).
abstract: X/X translocations are quite rare in humans. The effect of this anomaly on the phenotype is variable and depends on the amount of deleted material and whether the chromosomes are joined by their long or short arms. We report an unusual case of Turner syndrome mosaicism in a 16-year-old girl, who was referred to our Institute for primary amenorrhoea associated with short stature. Endocrine evaluation revealed hypergonadotropic hypogonadism, which required a study of the karyotype. Cytogenetic analysis, performed on peripheral blood leucocytes, showed a mos 45,X/46,X,ter rea (X;X)(p22.3;p22.3) de novo karyotype. The prevalent cell line was 45,X (90% cells). A second cell line (10% cells) showed a very large marker chromosome, similar to a large metacentric chromosome. FISH (fluorescent in situ hybridisation) and molecular analysis revealed that the marker chromosome was dicentric and totally derived from the paternal X chromosome.
authors.affiliation: Istituto di Neurogenetica e Neurofarmacologia, National Research Council, Cagliari, Italy. a.nuc@tiscali.it
authors.forename: Anna Lisa
authors.initials: AL
authors.lastname: Nucaro
authors.forename: Paola
authors.initials: P
authors.lastname: Melis
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Casini
authors.forename: Rossano
authors.initials: R
authors.lastname: Rossino
authors.forename: Milena
authors.initials: M
authors.lastname: Cau
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Melis
authors.forename: Sandro
authors.initials: S
authors.lastname: Loche
mesh_terms: D000293:Adolescent; D000568:Amenorrhea / Q000235:genetics*; D002869:Chromosome Aberrations; D041321:Chromosomes, Human, X / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009030:Mosaicism; D049590:Postpartum Period / Q000235:genetics*; D000091402:Prohibitins; D011944:Receptors, Androgen; D014424:Turner Syndrome / Q000235:genetics*
chemical_list: C410798:AR protein, human; C000717331:PHB2 protein, human; D000091402:Prohibitins; D011944:Receptors, Androgen