A heterozygous mutation in RPGR associated with X-linked retinitis pigmentosa in a patient with Turner syndrome mosaicism (45,X/46,XX)

Am J Med Genet A. 2018 Jan;176(1):214-218. doi: 10.1002/ajmg.a.38501. Epub 2017 Nov 14.

Abstract

Turner syndrome with retinitis pigmentosa (RP) is rare, with only three cases reported based on clinical examination alone. We summarized the 4-year follow-up and molecular findings in a 28-year-old patient with Turner syndrome and the typical features of short stature and neck webbing, who also had X-linked RP. Her main complaints were night blindness and progressive loss of vision since the age of 9 years. Ophthalmologic examination, optical coherent tomographic imaging, and visual electrophysiology tests showed classic manifestations of RP. The karyotype of peripheral blood showed mosaicism (45,X [72%]/46,XX[28%]). A novel heterozygous frameshift mutation (c.2403_2406delAGAG, p.T801fsX812) in the RP GTPase regulator (RPGR) gene was detected using next generation sequencing and validated by Sanger sequencing. We believe that this is the first report of X-linked RP in a patient with Turner syndrome associated with mosaicism, and an RPGR heterozygous mutation. We hypothesize that X-linked RP in this woman is not related to Turner syndrome, but may be a manifestation of the lack of a normal paternal X chromosome with intact but mutated RPGR.

Keywords: Turner syndrome; X-linked retinitis pigmentosa; heterozygous mutation.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Eye Proteins / genetics*
  • Female
  • Frameshift Mutation
  • Genes, X-Linked*
  • Genomics / methods
  • Heterozygote*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Male
  • Mutation*
  • Pedigree
  • Phenotype
  • Retinitis Pigmentosa / diagnosis*
  • Retinitis Pigmentosa / genetics*
  • Sequence Analysis, DNA
  • Turner Syndrome / diagnosis*
  • Turner Syndrome / genetics*

Substances

  • Eye Proteins
  • RPGR protein, human