Transthyretin Ala36Pro mutation in a Chinese pedigree of familial transthyretin amyloidosis with elevated vitreous and serum vascular endothelial growth factor

Exp Eye Res. 2013 May:110:44-9. doi: 10.1016/j.exer.2013.02.005. Epub 2013 Feb 21.

Abstract

The familial transthyretin (TTR) amyloidosis (FTA) demonstrates variable penetrance of clinical features associated with mutations in the plasma thyroid hormone-binding protein TTR gene. The purpose of this study was to assess the ocular features, to analyze vitreous and serum vascular endothelial growth factor (VEGF) levels, and to identify the genetic defect in a Chinese family with TTR FTA. The pedigree of interest was a three-generation family with eleven members. The primary ocular signs were vitreous opacities, beginning from the third or fourth decade, accompanied by retinal vasculitis, hemorrhages, and widespread pinpoint deposits in the peripheral retina. Two patients underwent vitrectomy with marked improvement of visual acuity postoperatively. Vitreous and serum samples for VEGF were analyzed with an enzyme-linked immunosorbent assay (ELISA). Forty-eight healthy adult volunteers were enrolled as a control group for the analysis of serum VEGF. Eight subjects who underwent vitrectomy for a macular epiretinal membrane or macular hole were enrolled as control for the analysis of vitreous VEGF. Both serum and vitreous VEGF levels of patients were raised compared to that of controls. Venous blood was collected from family members and the genomic DNA was extracted. All exons and exon-intron boundaries of the TTR gene were sequenced. A previously-described pathogenic transversion in exon 2 (c.G106C, p.Ala36Pro) was identified. Within this family eight individuals were confirmed as affected. In conclusion, a Chinese family with TTR Ala36Pro associated FTA is characterized by early ocular involvement. Widespread pinpoint lesions indicate RPE lesions caused by TTR deposition. FTA is associated with increased VEGF levels, both in serum and vitreous.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Amyloid Neuropathies, Familial / diagnosis
  • Amyloid Neuropathies, Familial / genetics*
  • Amyloid Neuropathies, Familial / metabolism
  • Asian People / genetics*
  • DNA Mutational Analysis
  • Electrooculography
  • Electroretinography
  • Enzyme-Linked Immunosorbent Assay
  • Eye Diseases / diagnosis
  • Eye Diseases / genetics
  • Eye Diseases / metabolism
  • Female
  • Fluorescein Angiography
  • Humans
  • Male
  • Middle Aged
  • Pedigree
  • Point Mutation*
  • Polymerase Chain Reaction
  • Prealbumin / genetics*
  • Retinal Hemorrhage / diagnosis
  • Retinal Hemorrhage / genetics
  • Retinal Hemorrhage / metabolism
  • Retinal Vasculitis / diagnosis
  • Retinal Vasculitis / genetics
  • Retinal Vasculitis / metabolism
  • Tomography, Optical Coherence
  • Vascular Endothelial Growth Factor A / blood*
  • Visual Acuity / physiology
  • Vitrectomy
  • Vitreous Body / metabolism*
  • Vitreous Body / pathology
  • Young Adult

Substances

  • Prealbumin
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A

Supplementary concepts

  • Amyloidosis, Hereditary, Transthyretin-Related