The Quest for a Donor: Probability Based Methods Offer Help.

• When a patient in need of a stem cell transplant has no compatible donor within his or herclosest family, and no matched unrelated donor can be found, a remaining option is to searchwithin the patient’s extended family. This situation often arises when the patient is of anethnic minority, originating from a country that lacks a well-developed stem cell donorprogram, and has HLA haplotypes that are rare in his or her country of residence. Searchingwithin the extended family may be time-consuming and expensive, and tools to calculate theprobability of a match within groups of untested relatives would facilitate the search.We present a general approach to calculating the probability of a match in a given relative, orgroup of relatives, based on the pedigree, and on knowledge of the genotypes of some of theindividuals. The method extends previous approaches by allowing the pedigrees to beconsanguineous and arbitrarily complex, with deviations from Hardy-Weinberg equilibrium.We show how this extension has a considerable effect on results, in particular for rarehaplotypes. The methods are exemplified using freeware programs to solve a case of practicalimportance.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Medicinsk genetik (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Medical Genetics (hsv//eng)

NATURVETENSKAP  -- Matematik -- Sannolikhetsteori och statistik (hsv//swe)

NATURAL SCIENCES  -- Mathematics -- Probability Theory and Statistics (hsv//eng)

Keyword

pedigree calculations

Donor search

consanguinity

Donor search; pedigree calculations; consanguinity

Publication and Content Type

art (subject category)

vet (subject category)