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The Ensu scoring system in genetic counselling
Author(s) -
MURPHY E. A.
Publication year - 1970
Publication title -
annals of human genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 77
eISSN - 1469-1809
pISSN - 0003-4800
DOI - 10.1111/j.1469-1809.1970.tb00221.x
Subject(s) - probabilistic logic , graph , linkage (software) , certainty , genetic counseling , computer science , genetics , lod score , numerical digit , mathematics , statistics , gene , theoretical computer science , biology , artificial intelligence , gene mapping , arithmetic , geometry , chromosome
SUMMARY As a device for systematically computing the posterior probability that a woman is the carrier of an X ‐linked recessive disorder, a new scoring system has been devised. The information provided by a woman and her male descendants is condensed into an equivalent number of normal sons. Thus if the likelihood ratio of her and her descendants, supposing her a carrier, to that supposing her wild‐type is expressible as (1/2) a , the score is a Equivalent Normal Son Units (Ensu). The method, designed in the first place to deal with strictly recessive disorders, is readily extended to the case where the carrier state can be identified with greater or less certainty and the case where other pertinent probabilistic information such as linkage data is available. Tables and a graph are provided which should allow three‐digit accuracy, sufficient for all practical purposes.