Long-term follow-up and analysis of monozygotic twins concordant for 45,X/46,XY peripheral blood karyotype but discordant for phenotypic sex

Sandra P. Tho, Robert Jackson, Anita S. Kulharya, Richard H. Reindollar, Lawrence C Layman, Paul G McDonough

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

We report on the follow-up of a set of monozygotic (MZ) twins who were concordant for peripheral blood karyotype 45,X/46,XY but discordant for phenotypic sex. One twin is a phenotypically normal male and the other twin has asymetrical gonadal dysgenesis. The female twin has the mos45,X/46,XY karyotype in all four tissues: left testis, right streak, vas deferens, and clitoral skin. The normal male twin has the normal 46,XY karyotype in all three tissues tested: foreskin, scrotal skin, and testis. Follow-up of the twins at age 21, revealed persistence of mos45,X/46,XY karyotype in peripheral blood into adult life. However, the male grew up with normal male stature, reaching an adult height of 182 cm. The female twin received low dose estrogen replacement with complete breast development at age 14 years. She reached an adult height of 156 cm. At 21 years of age the male twin had normal testicular endocrine function, but severe oligospermia. The long-term follow-up of this set of MZ twins indicate that the male twin has the mosaicism confined to peripheral blood and has the normal 46,XY male constitution. This was further confirmed by his normal male stature and normal testicular endocrine function. The 45X cell line is likely due to his receiving these cells passively from his twin sister via placental anastomoses in utero. The exposure to these 45,X cells during development may have had an impact on his spermatogenesis.

Original languageEnglish (US)
Pages (from-to)2616-2622
Number of pages7
JournalAmerican Journal of Medical Genetics, Part A
Volume143
Issue number21
DOIs
StatePublished - Nov 1 2007

Keywords

  • 45,X/46,XY karyotype
  • Mixed/asymmetrical gonadal dysgenesis
  • Monozygotic twins
  • Mosaicism
  • Short tandem repeat (STR) analysis

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

Fingerprint Dive into the research topics of 'Long-term follow-up and analysis of monozygotic twins concordant for 45,X/46,XY peripheral blood karyotype but discordant for phenotypic sex'. Together they form a unique fingerprint.

  • Cite this