Multipoint analysis using affected sib pairs: Incorporating linkage evidence from unlinked regions

Kung Yee Liang, Yen Feng Chiu, Terri H. Beaty, Matthias Wjst

Research output: Contribution to journalReview articlepeer-review

19 Scopus citations


In this paper, we proposed a multipoint method to assess evidence of linkage to one region by incorporating linkage evidence from another region. This approach uses affected sib pairs in which the number of alleles shared identical by descent (IBD) is the primary statistic. This generalized estimating equation (GEE) approach is robust in that no assumption about the mode of inheritance is required, other than assuming the two regions being considered are unlinked and that there is no more than one susceptibility gene in each region. The method proposed here uses data from all available families to simultaneously test the hypothesis of statistical interaction between regions and to estimate the location of the susceptibility gene in the target region. As an illustration, we have applied this GEE method to an asthma sib pair study (Wjst et al. [1999] Genomics 58:1-8), which earlier reported evidence of linkage to chromosome 6 but showed no evidence for chromosome 20. Our results yield strong evidence to chromosome 20 (P value = 0.0001) after incorporating linkage information from chromosome 6. Furthermore, it estimates with 95% certainty that the map location of the susceptibility gene is flanked by markers D20S186 and D20S101, which are approximately 16.3 cM apart.

Original languageEnglish (US)
Pages (from-to)105-122
Number of pages18
JournalGenetic epidemiology
Issue number2
StatePublished - 2001


  • Affected sib pairs
  • Complex disease
  • Generalized estimating equations
  • Identity by descent
  • Two locus models

ASJC Scopus subject areas

  • Epidemiology
  • Genetics(clinical)


Dive into the research topics of 'Multipoint analysis using affected sib pairs: Incorporating linkage evidence from unlinked regions'. Together they form a unique fingerprint.

Cite this