Τίτλος:
Detection of a novel unbalanced X;21 translocation in a girl with Turner syndrome phenotype
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Objective: To describe a novel unbalanced X;21 translocation resulting in a derivative pseudodicentric chromosome X;21 lacking the critical region for ovarian development and function, in a 16-year-old girl referred for cytogenetic analysis due to primary amenorrhea and Turner-like features. Methods: Cytogenetic analysis of the proband and her parents was performed on peripheral blood lymphocytes by GTG banding. Molecular cytogenetic FISH analysis was performed on metaphase preparations, using X chromosome centromeric probe and telomeric and pancentromeric peptide nucleic acid (PNA) analog probes. The HUMARA assay as well as methylation studies for PCSK1N and FMR-1 loci were performed. Results: Cytogenetic analysis revealed a de novo unbalanced X;21 translocation, described as 45,X,der(X)t(X;21)(q22.2;p11.2),-21. FISH analysis showed that the derivative X chromosome carried both the X and 21 centromeres, as well as, the Xp and 21q telomeres. The karyotype was thus reevaluated as 45,X,psu dic(21;X)(21qter→21p13::Xq22.2→Xpter),-21. X inactivation studies revealed that the derivative chromosome was of paternal origin and confirmed the selective inactivation of the derivative X segment of the pseudodicentric chromosome. Conclusions: Primary amenorrhea and other Turner-like characteristics of the proband are apparently due to the loss of the Xq22.2→Xqter critical region which contains critical genes for the ovarian development and function. The chromosome X segment of the derivative pseudodicentric chromosome is selectively inactivated, but inactivation does not seem to spread onto the translocated chromosome 21, accounting probably for the lack of severe clinical consequences which would result from monosomy 21. © 2020 Informa UK Limited, trading as Taylor & Francis Group.
Συγγραφείς:
Kouvidi, E.
Zachaki, S.
Selenti, N.
Veltra, D.
Evmorfopoulou, T.
Tsoutsou, E.
Tzifa, G.
Sofocleous, C.
Gagos, S.
Mavrou, A.
Περιοδικό:
Gynecological Endocrinology
Εκδότης:
Taylor and Francis Ltd.
Λέξεις-κλειδιά:
androstenedione; estradiol; genomic DNA; peptide nucleic acid; prolactin; testosterone; thyroid hormone, abdominal radiography; adolescent; Article; case report; centromere; chromosome 21; chromosome analysis; chromosome translocation; clinical article; echography; female; fluorescence in situ hybridization; high arched palate; human; hypergonadotropic hypogonadism; intellectual impairment; karyotype; learning disorder; metaphase; micrognathia; monosomy; monosomy 21; ovary development; peripheral lymphocyte; phenotype; physical examination; primary amenorrhea; priority journal; secondary sexual characteristics; short stature; speech delay; speech therapy; telomere; Turner syndrome; unbalanced X;21 translocation; X chromosome; X chromosome inactivation; gene translocation; genetics; pathophysiology; Turner syndrome, Adolescent; Chromosomes, Human, Pair 21; Chromosomes, Human, X; Female; Humans; In Situ Hybridization, Fluorescence; Translocation, Genetic; Turner Syndrome
DOI:
10.1080/09513590.2020.1865907
