Unbalanced Y;7 Translocation between Two Low-Similarity Sequences Leading to SRY-Positive 45,X Testicular Disorders of Sex Development

Cytogenet Genome Res. 2019;158(3):115-120. doi: 10.1159/000501378. Epub 2019 Jul 5.

Abstract

Unbalanced translocations of Y-chromosomal fragments harboring the sex-determining region Y gene (SRY) to the X chromosome or an autosome result in 46,XX and 45,X testicular disorders of sex development (DSD), respectively. Of these, Y;autosome translocation is an extremely rare condition. Here, we identified a 20-year-old man with a 45,X,t(Y;7)(q11.21;q35) karyotype, who exhibited unilateral cryptorchidism, small testis, intellectual disability, and various congenital anomalies. The fusion junction of the translocation was blunt, and the breakpoint-flanking regions shared only 50% similarity. These results indicate that Y;autosome translocations can occur between 2 low-similarity sequences, probably via nonhomologous end joining. Furthermore, translocations of a Ypterq11.21 fragment to 7q35 likely result in normal or only mildly impaired male-type sexual development, along with various clinical features of 7q deletion syndrome, although their effects on adult testicular function remain to be studied.

Keywords: 7q Deletion; DSD; Nonhomologous end joining; Sex chromosome; Translocation.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Chromosome Breakpoints
  • Chromosomes, Human, Pair 7 / genetics*
  • Chromosomes, Human, Y / genetics*
  • Disorders of Sex Development / genetics*
  • Female
  • Genes, sry / genetics*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Infant, Newborn
  • Karyotype
  • Male
  • Testicular Diseases / genetics*
  • Translocation, Genetic / genetics*
  • Young Adult