In connection therewith, LDS Church leaders have regularly taught the importance of establishing and supporting family organizations.
"[30] Formally constituted family organizations figure prominently among descendants of some Mormon pioneers and other early converts to the LDS Church.
[31][32] In 1971 the Internal Revenue Service of the United States issued a Revenue Ruling determining that non-profit family organizations that are expressly "formed to compile genealogical research data on its family members in order to perform religious ordinances in accordance with the precepts of the religious denomination to which family members belong" are exempt under Section 501(c)(3).
[33][34] Given their extensive documentation of lineages connecting many thousands of living individuals to a single common ancestor, their relatively larger extended family size (attributable in part to the early Mormon practice of plural marriage), relatively larger immediate family size, religious emphasis on "clean" or healthy living, and relative longevity, the genealogical data maintained by many Mormon ancestral family organizations have also been instrumental in medical research of genetic disorders.
[35] The University of Utah has made unique contributions to the study of genetics due in part to long-term genealogy efforts of the LDS Church, which has allowed researchers to trace genetic disorders through several generations.