- http://sahirbhatnagar.com
- 2nd year PhD student (Biostatistics) with Celia
- Im interested in
- anything applied that can contribute to society
- big data
- reproducible research
- how to give a good talk
- Big believer in open source software
August 7, 2014 Statistical Genetics Journal Club
- A single measure of a sample - It reduces the data to one value - Need to know its sampling distribution to conduct hypothesis tests
\[ \textrm{Pearson} = \frac{(Observed - Expected)^2}{Expected} \sim \chi^2_{(df)} \]
\[ Z = \frac{\bar{X}-\mu}{\sigma} \sim \mathcal{N}(0,1) \]
A novel population-based imputation approach: Prephasing Imputation
 | A non transmitted | B non transmitted | Total |
---|---|---|---|
A transmitted | a | b | a+b |
B transmitted | c | d | c+d |
Total | a+c | b+d | 2n |
Need to have at least 1 heterozygous parent for trio to be informative
Consider a marker with two alleles \(A\) and \(B\).
Informative families are:
Within an informative nuclear family define:
\[D=\frac{1}{n_T + n_S} \left( \sum X_{T} + \sum X_{S} \right) \]
For \(k=1,\ldots,N\) unrelated informative pedigrees
\[ PDT_{test} = \frac{\sum D_k}{\sqrt{\sum D_k^2 }} \sim \mathcal{N}(0,1) \]
\[ U = \sum T^* \left[ X-E(X|P) \right] \rightarrow \textrm{Covariance} \] \[ FBAT = \frac{U^2}{var(U)} \sim \chi^2_{(1)} \rightarrow \textrm{Test Statistic} \]