PMID- 28630649
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20201001
IS  - 1755-8166 (Print)
IS  - 1755-8166 (Electronic)
IS  - 1755-8166 (Linking)
VI  - 10
DP  - 2017
TI  - A complete duplication of X chromosome resulting in a tricentric isochromosome 
      originated by centromere repositioning.
PG  - 22
LID - 10.1186/s13039-017-0323-7 [doi]
LID - 22
AB  - BACKGROUND: Neocentromeres are rare and considered chromosomal aberrations, 
      because a non-centromeric region evolves in an active centromere by mutation. The 
      literature reported several structural anomalies of X chromosome and they 
      influence the female reproductive capacity or are associated to Turner syndrome 
      in the presence of monosomy X cell line. CASE PRESENTATION: We report a case of 
      chromosome X complex rearrangement found in a prenatal diagnosis. The fetal 
      karyotype showed a mosaicism with a 45,X cell line and a 46 chromosomes second 
      line with a big marker, instead of a sex chromosome. The marker morphology and 
      fluorescence in situ hybridization (FISH) characterization allowed us to identify 
      a tricentric X chromosome constituted by two complete X chromosome fused at the p 
      arms telomere and an active neocentromere in the middle, at the union of the two 
      Xp arms, where usually are the telomeric regions. FISH also showed the presence 
      of a paracentric inversion of both Xp arms. Furthermore, fragility figures were 
      found in 56% of metaphases from peripheral blood lymphocytes culture at birth: a 
      shorter marker chromosome and an apparently acentric fragment frequently lost. 
      CONCLUSIONS: At our knowledge, this is the first isochromosome of an entire 
      non-acrocentric chromosome. The neocentromere is constituted by canonical 
      sequences but localized in an unusual position and the original centromeres are 
      inactivated. We speculated that marker chromosome was the result of a double 
      rearrangement: firstly, a paracentric inversion which involved the Xp arm, 
      shifting a part of the centromere at the p end and subsequently a duplication of 
      the entire X chromosome, which gave rise to an isochromosome. It is possible to 
      suppose that the first event could be a result of a non-allelic homologous 
      recombination mediated by inverted low-copy repeats. As expected, our case shows 
      a Turner phenotype with mild facial features and no major skeletal deformity, 
      normal psychomotor development and a spontaneous development of puberty and 
      menarche, although with irregular menses since the last follow-up.
FAU - Villa, N
AU  - Villa N
AD  - Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 
      Monza, Italy. ISNI: 0000 0004 1756 8604. GRID: grid.415025.7
FAU - Conconi, D
AU  - Conconi D
AD  - School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy. ISNI: 
      0000 0001 2174 1754. GRID: grid.7563.7
FAU - Benussi, D Gambel
AU  - Benussi DG
AD  - Medical Genetics, Institute for Maternal and Child Health I.R.C.C.S. "Burlo 
      Garofolo", Trieste, Italy.
FAU - Tornese, G
AU  - Tornese G
AD  - Department of Pediatrics, Institute for Maternal and Child Health I.R.C.C.S. 
      "Burlo Garofolo", Trieste, Italy.
FAU - Crosti, F
AU  - Crosti F
AD  - Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 
      Monza, Italy. ISNI: 0000 0004 1756 8604. GRID: grid.415025.7
FAU - Sala, E
AU  - Sala E
AD  - Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 
      Monza, Italy. ISNI: 0000 0004 1756 8604. GRID: grid.415025.7
FAU - Dalpra, L
AU  - Dalpra L
AD  - Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 
      Monza, Italy. ISNI: 0000 0004 1756 8604. GRID: grid.415025.7
AD  - School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy. ISNI: 
      0000 0001 2174 1754. GRID: grid.7563.7
FAU - Pecile, V
AU  - Pecile V
AD  - Medical Genetics, Institute for Maternal and Child Health I.R.C.C.S. "Burlo 
      Garofolo", Trieste, Italy.
LA  - eng
PT  - Case Reports
DEP - 20170613
PL  - England
TA  - Mol Cytogenet
JT  - Molecular cytogenetics
JID - 101317942
PMC - PMC5470200
OTO - NOTNLM
OT  - Chromosome complex rearrangement
OT  - Telomeric-centromeric X rearrangement
EDAT- 2017/06/21 06:00
MHDA- 2017/06/21 06:01
PMCR- 2017/06/13
CRDT- 2017/06/21 06:00
PHST- 2017/03/27 00:00 [received]
PHST- 2017/05/24 00:00 [accepted]
PHST- 2017/06/21 06:00 [entrez]
PHST- 2017/06/21 06:00 [pubmed]
PHST- 2017/06/21 06:01 [medline]
PHST- 2017/06/13 00:00 [pmc-release]
AID - 323 [pii]
AID - 10.1186/s13039-017-0323-7 [doi]
PST - epublish
SO  - Mol Cytogenet. 2017 Jun 13;10:22. doi: 10.1186/s13039-017-0323-7. eCollection 
      2017.