Genetics beyond Mendel

PREVIEW

As the Human Genome Project unfolds, more and more genetic disorders are being found that are not transmitted in the usual dominant, recessive, or X-linked pattern. How do you explain these strange exceptions to Mendelian rules to your patients and their families? In this article, Dr Wagstaff discusses imprinting, trinucleotide repeat expansion, mitochondrial inheritance, and mosaicism and explains how they occur and how they affect transmission of inherited diseases.