Ferriman, Annabel. May 12, 2001. First cases of human germline genetic modification announced. The British Medical Journal 322:1144. People object to ooplasmic transfer because the resulting children have three genetic parents.

Seashore, Margretta R. December 26, 2002. Tetrahydrobiopterin and dietary restriction in mild phenylketonuria. The New England Journal of Medicine 347(26):2094–95. Nearly all cases of PKU are due to an enzyme deficiency, but a few result from an abnormal cofactor that the enzyme requires to function. Therefore, PKU is genetically heterogeneic.

Sijbrands, Eric J. G., et al. April 28, 2001. Mortality over two centuries in large pedigree with familial hypercholesterolemia: Family tree mortality study. The British Medical Journal 322:1019–23. Variable expressivity in FH reflects diet and exercise habits and the effects of other genes.

Smeitink, Jan, and Lambert van den Heuvel. June 1999. Human mitochondrial complex I in health and disease. The American Journal of Human Genetics 64:1505–9. Many inherited diseases affecting muscles stem from mutations in mitochondrial genes.