Biomedical subjects

Wing K Fung

Publications and source records attributed to Wing K Fung.

22 records · Page 2Linked to original sources

PubMed2002

Evaluating mixed stains with contributors of different ethnic groups under the NRC-II Recommendation 4.1.

In countries with multiple racial or ethnic groups, it is not uncommon that contributors to a mixed stain or a DNA mixture belong to different ethnic origins. This paper derives a general formula for evaluating the likelihood ratio in such situations based on the commonly adopted Recommendation 4.1 of the U.S. Second National Research Council Report on the evaluation of DNA evidence. The restrictive Hardy-Weinberg assumption is not taken in this paper. Our formula generalizes the results of Fung and Hu for a single ethnic group, and of Weir et al. under the Hardy-Weinberg law for a single, and Fukshansky and Bär for multiple ethnic groups. The effect of different ethnic groups of contributors to the interpretation of mixtures is illustrated through the analysis of the Simpson case.

Alleles↗

PubMed2002

Interpreting DNA mixtures with the presence of relatives.

The assessment of DNA mixtures with the presence of relatives is discussed in this paper. The kinship coefficients are incorporated into the evaluation of the likelihood ratio and we first derive a unified expression of joint genotypic probabilities. A general formula and seven types of detailed expressions for calculating likelihood ratios are then developed for the case that a relative of the tested suspect is an unknown contributor to the mixed stain. These results can also be applied to the case of a non-tested suspect with one tested relative. Moreover, the formula for calculating the likelihood ratio when there are two related unknown contributors is given. Data for a real situation are given for illustration, and the effect of kinship on the likelihood ratio is shown therein. Some interesting findings are obtained.

Algorithms↗

PubMed2002

Power of exclusion revisited: probability of excluding relatives of the true father from paternity.

In parentage testing using DNA markers, the formulae for calculating the probability of exclusion generally overstate the power of a test battery by considering its ability to exclude a random man. It is known that in many cases, in particular immigration applications, the false father is more likely to be a relative, e.g. brother, of the true father than an unrelated man. This work presents formulae that take this consideration into account. A practical example using Hong Kong data is provided to illustrate the effect of the modification. Also discussed is how the expected efficacy of a test battery will be affected when possible mutations and null alleles or genetic inconsistencies are taken into consideration.

DNA Fingerprinting↗

PubMed2002

The statistical evaluation of DNA mixtures with contributors from different ethnic groups.

The effect of a structured population on the evaluation of forensic mixed stains has been considered by the authors and others. However, in countries with multiple racial or ethnic groups, it is not uncommon that contributors to a DNA mixture are of different ethnic groups. A famous example is the OJ Simpson case in which the suspect was an African-American, the victims were Caucasian Americans and the true perpetrator(s) could be from any ethnic group(s). In this paper six common mixture cases are considered and the formulae for likelihood ratios are derived. These formulae can help forensic DNA scientists acquire a better understanding of the problem. The effect of different ethnic groups is illustrated using a case in Hong Kong.

Alleles↗