A mutation causing Alport syndrome with tardive hearing loss is common in the western United States

Am J Hum Genet. 1996 Jun;58(6):1157-65.


Mutations in the COL4A5 gene, located at Xq22, cause Alport syndrome (AS), a nephritis characterized by progressive deterioration of the glomerular basement membrane and usually associated with progressive hearing loss. We have identified a novel mutation, L1649R, present in 9 of 121 independently ascertained families. Affected males shared the same haplotype of eight polymorphic markers tightly linked to COL4A5, indicating common ancestry. Genealogical studies place the birth of this ancestor >200 years ago. The L1649R mutation is a relatively common cause of Alport syndrome in the western United States, in part because of the rapid growth and migratory expansion of mid-nineteenth-century pioneer populations carrying the gene. L1649R affects a highly conserved residue in the NC1 domain, which is involved in key inter- and intramolecular interactions, but results in a relatively mild disease phenotype. Renal failure in an L1649R male typically occurs in the 4th or 5th decade and precedes the onset of significant hearing loss by approximately 10 years.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Base Sequence
  • Child
  • Collagen / genetics*
  • DNA Primers
  • Female
  • Genetic Carrier Screening
  • Genetic Linkage
  • Hearing Loss / epidemiology
  • Hearing Loss / genetics*
  • Humans
  • Incidence
  • Iowa
  • Kidney Failure, Chronic / genetics
  • Kidney Failure, Chronic / physiopathology
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Nephritis, Hereditary / epidemiology
  • Nephritis, Hereditary / genetics*
  • Pedigree
  • Point Mutation*
  • RNA / isolation & purification
  • Skin
  • United States / epidemiology
  • Utah


  • DNA Primers
  • RNA
  • Collagen