title: Constitutional telomeric association (Y;7) in a patient with a female phenotype.
abstract: Telomeric associations (TAs) are fusions between two telomeres of two different chromosomes without visible loss of chromosomal material. Constitutional telomeric associations are rare chromosomal anomalies. We report on the cytogenetic and molecular analyses of a TA involving chromosomes Y and 7 in a child with a female phenotype. Prenatal cytogenetic analysis showed a 45,X chromosome complement in all cells. No fetal abnormality was identified at ultrasound examinations and the pregnancy went to term. During childhood, the proband had gonadal dysgenesis but no other phenotypic manifestations of Turner syndrome. Molecular genetic analyses showed the presence of genomic DNA of the SRY gene without any mutation. Karyotyping and fluorescent in situ hybridization (FISH) analyses on blood showed two cell lines: one cell line with a TA involving chromosomes Y and 7 [46,X,tas(Y;7)(p11.32;q36.3)] and a second cell line with a 45,X pattern. A human pantelomeric repeat TTAGGG probe hybridized to the junction of the TA within the derivative chromosome. FISH and array comparative genomic hybridization (aCGH) analyses demonstrated that tas(Y;7) occurred without detectable loss of any sequence at the derivative chromosome. SNP array analysis excluded an uniparental isodisomy of chromosome 7. Knowing more about TAs will help geneticists to deliver accurate genetic counseling.
authors.affiliation: CHU Nantes, Service de Génétique Médicale, Nantes, France. claire.beneteau@chu-nantes.fr
authors.forename: Claire
authors.initials: C
authors.lastname: Beneteau
authors.forename: Sabine
authors.initials: S
authors.lastname: Baron
authors.forename: Albert
authors.initials: A
authors.lastname: David
authors.forename: Frédérique
authors.initials: F
authors.lastname: Jossic
authors.forename: Damien
authors.initials: D
authors.lastname: Poulain
authors.forename: Sébastien
authors.initials: S
authors.lastname: Schmitt
authors.forename: Marc-David
authors.initials: MD
authors.lastname: Leclair
authors.forename: Philippe
authors.initials: P
authors.lastname: Piloquet
authors.forename: Cédric
authors.initials: C
authors.lastname: Le Caignec
mesh_terms: D002460:Cell Line; D002648:Child; D002871:Chromosome Banding; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics*; D041322:Chromosomes, Human, Y / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D005260:Female; D006059:Gonadal Dysgenesis / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D008214:Lymphocytes / Q000166:cytology; D009030:Mosaicism; D010641:Phenotype; D011247:Pregnancy; D012729:Sex Chromosome Aberrations; D016615:Telomere / Q000235:genetics*