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).
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.
Nucaro
Anna Lisa
AL
Istituto di Neurogenetica e Neurofarmacologia, National Research Council, Cagliari, Italy. a.nuc@tiscali.it
Melis
Paola
P
Casini
Maria Rosaria
MR
Rossino
Rossano
R
Cau
Milena
M
Melis
Maria Antonietta
MA
Loche
Sandro
S
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*
C410798:AR protein, human; C000717331:PHB2 protein, human; D000091402:Prohibitins; D011944:Receptors, Androgen