A dominant mutation in hexokinase 1 (HK1) causes retinitis pigmentosa

Lori S. Sullivan, Daniel C. Koboldt, Sara J. Bowne, Steven Lang, Susan H. Blanton, Elizabeth Cadena, Cheryl E. Avery, Richard A. Lewis, Kaylie Webb-Jones, Dianna H. Wheaton, David G. Birch, Razck Coussa, Huanan Ren, Irma Lopez, Christina Chakarova, Robert K. Koenekoop, Charles A. Garcia, Robert S. Fulton, Richard K. Wilson, George M. WeinstockStephen P. Daiger

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


Purpose. To identify the cause of retinitis pigmentosa (RP) in UTAD003, a large, six-generation Louisiana family with autosomal dominant retinitis pigmentosa (adRP).

Methods. A series of strategies, including candidate gene screening, linkage exclusion, genome-wide linkage mapping, and whole-exome next-generation sequencing, was used to identify a mutation in a novel disease gene on chromosome 10q22.1. Probands from an additional 404 retinal degeneration families were subsequently screened for mutations in this gene.

Results. Exome sequencing in UTAD003 led to identification of a single, novel coding variant (c.2539G>A, p.Glu847Lys) in hexokinase 1 (HK1) present in all affected individuals and absent from normal controls. One affected family member carries two copies of the mutation and has an unusually severe form of disease, consistent with homozygosity for this mutation. Screening of additional adRP probands identified four other families (American, Canadian, and Sicilian) with the same mutation and a similar range of phenotypes. The families share a rare 450-kilobase haplotype containing the mutation, suggesting a founder mutation among otherwise unrelated families.

Conclusions. We identified an HK1 mutation in five adRP families. Hexokinase 1 catalyzes phosphorylation of glucose to glucose-6-phosphate. HK1 is expressed in retina, with two abundant isoforms expressed at similar levels. The Glu847Lys mutation is located at a highly conserved position in the protein, outside the catalytic domains. We hypothesize that the effect of this mutation is limited to the retina, as no systemic abnormalities in glycolysis were detected. Prevalence of the HK1 mutation in our cohort of RP families is 1%.

Original languageEnglish (US)
Pages (from-to)7147-7158
Number of pages12
JournalInvestigative Ophthalmology and Visual Science
Issue number11
StatePublished - Sep 4 2014


  • Hexokinase
  • Inherited retinal dystrophy
  • Retinitis pigmentosa

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience


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