Methoden vergleichen

	Transmission Disequilibrium Test	IBD-Mapping
Fachgebiet	Genetik	Genetik
Familie	Process / pipeline	Process / pipeline
Entstehungsjahr	1993	1987
Urheber	Richard Spielman & Warren Ewens	Eric Lander & David Botstein
Typ	Hypothesis test	Genomic mapping method
Wegweisende Quelle	Spielman, R. S., McGinnis, R. E., & Ewens, W. J. (1993). Transmission test for linkage disequilibrium. American Journal of Human Genetics, 52(3), 506–516.	Lander, E. S., & Botstein, D. (1987). Homozygosity mapping of autosomal recessive disorders in consanguineous families. American Journal of Human Genetics, 36(3), 537–551.
Aliasnamen	TDT, Family-based association test	IBD mapping, Autozygosity mapping, Homozygosity mapping
Verwandt	4	4
Zusammenfassung	The Transmission Disequilibrium Test (TDT) is a family-based statistical method for testing genetic association with disease or traits while inherently controlling for population stratification. Developed by Spielman and Ewens in 1993, the TDT examines whether an allele is preferentially transmitted from heterozygous parents to affected children compared to unaffected children. By comparing transmission patterns within families, the TDT avoids the confounding effects of population structure that plague case-control studies, making it particularly valuable in admixed or stratified populations.	Identity-by-descent (IBD) mapping is a genetic mapping technique that identifies disease loci in consanguineous families or isolated populations by detecting homozygous chromosomal segments shared among affected individuals. Developed by Lander and Botstein in 1987, this method exploits the fact that rare disease alleles in related individuals must lie within shared ancestral DNA blocks. By mapping regions where affected individuals are homozygous at multiple markers, researchers can localize disease genes to narrowly defined genomic intervals without prior knowledge of the disease mechanism.