Exclusion of AR-CHED from the chromosome 20 region containing the PPMD and AD-CHED loci

Adam B. Kanis, Ali A. Al-Rajhi, Christine M. Taylor, William D. Mathers, Robert Folberg, Darryl Y. Nishimura, Val C. Sheffield, Edwin M. Stone

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Congenital hereditary endothelial dystrophy (CHED) is a disorder of the corneal endothelium and has been recognized to segregate in families with both autosomal dominant (AD) and autosomal recessive (AR) modes of transmission. AD-CHED has been previously linked to the pericentric region of chromosome 20. Posterior polymorphous dystrophy (PPMD), a corneal endothelial disorder showing phenotypic overlap with CHED, has also been previously genetically mapped to this region. The genetic interval containing AD-CHED is within the larger genetic interval containing the PPMD locus. This study sought to determine whether AR-CHED segregating in a consanguineous Saudi Arabian pedigree is linked to the previously mapped and overlapping loci for AD-CHED and PPMD on the pericentric region of chromosome 20. Forty members of a consanguineous Saudi Arabian pedigree segregating AR-CHED were ascertained. Short tandem-repeat polymorphic markers from the 20 cM interval on chromosome to containing both the PPMD and AD-CHED loci were used to genotype these individuals. LOD score analysis of the genotype data with the MENDEL software package utilizing a model of autosomal recessive inheritance with complete penetrance showed exclusion of CHED from the entire PPMD/AD-CHED interval by utilizing overlapping intervals of LOD scores of at least -2. The results obtained demonstrate that AR-CHED is not allelic to either AD-CHED or PPMD, although it has been proposed that AD-CHED may be allelic to PPMD. Thus, there are at least two genes responsible for CHED and PPMD.

Original languageEnglish (US)
Pages (from-to)243-249
Number of pages7
JournalOphthalmic Genetics
Issue number4
StatePublished - 1999
Externally publishedYes


  • Chromosome 20
  • Congenital heredity endothelial dystrophy
  • Linkage analysis

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Ophthalmology
  • Genetics(clinical)


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