New cholesterol disorder discovered As predicted from g...( ound equivalent to a heart attack risk...)

Taking into account that the original DNA sample was drawn from patients with cholesterol problems, the team was able to estimate that several hundred thousand people in the U.S. and Europe will be affected by defects in this gene.

The siblings with mutations in both copies of the CYP7A1 gene were, in effect, "human knockouts" for this gene. A powerful approach to determining how a particular gene functions is to knock out, or delete, both copies of the gene in mice and raise a line of mice lacking the gene. Such a mouse knockout has been developed for CYP7A1 but surprisingly, these mice do not exhibit the cholesterol problems predicted and found in people.

"The mouse model did not predict the significant increased cholesterol levels, but now that we have identified this disorder in patients, we hope that the new understanding of how LDL levels can become elevated will help prevent and treat atherosclerosis," said Clive R. Pullinger, PhD, research biochemist at the CVRI and lead author on the paper.

Pullinger identified the mutations in the suspected gene samples using a technique known as differential DNA melting, which pinpoints the mutated genes based on their abnormal mobility when the DNA is placed in an electrical field.

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Contact: Wallace Ravven
wravven@pubaff.ucsf.edu
415-476-2557
University of California - San Francisco
26-Jun-2002