Two girls with a de novo Xq rearrangement of paternal origin: t(X;9)(q24;q12) or rea(X)dup q

Taiwan J Obstet Gynecol. 2016 Apr;55(2):275-80. doi: 10.1016/j.tjog.2015.09.004.

Abstract

Objective: We report on two rare Xq rearrangements, namely a t(X;9)(q24;q12) found in a mildly-affected girl (Patient 1) and a rea(X)dup q concomitant with a rob(14;21)mat in a Down syndrome girl (Patient 2).

Case report: Both rearrangements were characterized by banding techniques [Giemsa (G), constitutive heterochromatin (C), and bromodeoxyuridine (BrdU) pulse], fluorescence in situ hybridization (FISH) assays, human androgen receptor (HUMAR) assays, and microarray analyses. Patient 1 had a t(X;9)(q24;q12)dn. Patient 2 had a de novo rea(X)(qter→q23 or q24::p11.2→qter) concomitant with an unbalanced rob(14;21)mat. X-Inactivation studies in metaphases and DNA revealed a fully skewed inactivation: the normal homolog was silenced in Patient 1 and the rea(X) in Patient 2. Both rearranged X chromosomes were of paternal descent. Microarray analyses revealed no imbalances in Patient 1 whereas loss of Xp (∼52 Mb) and duplication of Xq (∼44 Mb) and 21q were confirmed in Patient 2.

Conclusion: Our observations further document the cytogenetic heterogeneity and predominant paternal origin of certain de novo X-chromosome rearrangements.

Keywords: X-autosome translocation; Xq duplication; de novo; paternal descent; recombinant chromosome.

Publication types

  • Case Reports

MeSH terms

  • Abnormalities, Multiple / genetics
  • Child
  • Chromosome Duplication*
  • Chromosomes, Human, X / genetics*
  • Craniofacial Abnormalities / genetics
  • Down Syndrome / genetics
  • Female
  • Humans
  • Infant
  • Paternal Inheritance
  • Prohibitins
  • Sex Chromosome Aberrations*
  • Translocation, Genetic*