= Haplotype-relative-risk
{title2=$\widehat{\mathrm{OR}}=\frac{wz}{xy}$}
{wiki}
The haplotype-relative-risk design compares transmitted <alleles> to the corresponding untransmitted parental copies, used as internal controls for an affected offspring. If allele-1/allele-2 transmitted counts are $w,x$ and untransmitted counts are $y,z$, the allele-1 <odds ratio> estimate is $wz/(xy)$. An unmatched <Pearson chi-squared test of independence> treats this as a two-by-two table. The <transmission disequilibrium test> instead keeps parent-specific pairing and uses only discordant transmissions. The sampling assumptions of the unmatched calculation and any missing-parent reconstruction must be justified separately.
Back to article page
