title: Search for a correlation between telomere length and severity of retinitis pigmentosa due to the dominant rhodopsin Pro23His mutation.
abstract: OBJECTIVE
  Great variation exists in the age of onset of symptoms and the severity of disease at a given age in patients with retinitis pigmentosa (RP). The final pathway for this disease may involve apoptotic photoreceptor cell death. Telomere length is associated with biologic aging, senescence, and apoptosis. We evaluated whether the length of telomeres in leukocytes correlated with the severity of RP in patients with the Pro23His rhodopsin mutation who have shown marked heterogeneity in disease severity.
  
  
  METHODS
  We evaluated 122 patients with the Pro23His rhodopsin mutation. The patients' retinal function was stratified according to their 30-Hz cone electroretinogram (ERG). The length of telomeres in leukocytes was measured by the quantitative real time polymerase chain reaction (qRT-PCR) method in the 15 patients with the highest age-adjusted 30-Hz ERG amplitudes and in the 15 patients with the lowest amplitudes.
  
  
  RESULTS
  Mean leukocyte telomere length was similar in the 15 patients with the highest cone ERG amplitudes (median: 0.40 units; interquartile range 0.36-0.56) and the 15 patients with the lowest cone amplitudes (median: 0.41 units; inter quartile range 0.34 -0.64; p=0.95).
  
  
  CONCLUSIONS
  We found no evidence for an association between telomere length and the severity of RP as monitored by the cone ERG in patients with the Pro23His rhodopsin mutation.
authors.affiliation: Ocular Molecular Genetics Institute, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA, USA. d.t.hartong@ohk.umcg.nl
authors.forename: Dyonne T
authors.initials: DT
authors.lastname: Hartong
authors.forename: Terri L
authors.initials: TL
authors.lastname: McGee
authors.forename: Michael A
authors.initials: MA
authors.lastname: Sandberg
authors.forename: Eliot L
authors.initials: EL
authors.lastname: Berson
authors.forename: Folkert W
authors.initials: FW
authors.lastname: Asselbergs
authors.forename: Pim
authors.initials: P
authors.lastname: van der Harst
authors.forename: Immaculata
authors.initials: I
authors.lastname: De Vivo
authors.forename: Thaddeus P
authors.initials: TP
authors.lastname: Dryja