Genomics
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This page presents brief commentary on some of the most significant developments in genomics and in medical practice as it relates to the field of genomics. New items will be added from time to time - please check back periodically!

Mammogram Controversy

Recommendation for reduced frequency of mammograms

A government panel has recently recommended that the long-standing practice of giving routine mammograms to healthy women in their 40s should be terminated, and that older women should have mammograms less frequently than they do now. This has caused a major controversy and has triggered accusations that the government is trying to save money by reducing the quality of medical care.

In fact, the recommendations were not based on economics, but on the medical trade-offs between the risks and benefits involved. Like any medical procedure, mammograms have risks. The panel concluded that, for women who have no indications of elevated risk of breast cancer (and only for those women), the medical risks of the mammogram procedure outweigh the risks of the disease.

In this situation, any new information about a patient's overall risk of disease can have a dramatic affect on decisions the clinician must make. Ultimately, more accurate risk information can help improve the public health and reduce the costs of providing medical care.

New genomic risk tests provide precisely this kind of previously unavailable risk information.
Read a New York Times editorial on this topic:   

Parent-Specific Inheritance

A significant advance in disease risk prediction

Researchers in Iceland have recently identified risk markers for breast cancer, basal-cell carcinoma, and type 2 diabetes that confer differing levels of risk, depending on whether they are inherited from the mother or from the father. These markers (SNPs) are all on autosomes (not X or Y sex chromosomes), but are in regions controlled by sex-specific epigenetic imprinting.

In the most dramatic example, the at-risk allele of a particular SNP results in a 35% increase in risk of type 2 diabetes to anyone who inherits it from his or her father, but gives a 14% reduction in risk to anyone who inherits it from his or her mother. This SNP had been studied before, but did not appear to be relevant because, when paternal and maternal inheritance was not factored in, the two cases largely cancelled each other out.