In the final pages of his new book about personalized medicine, Francis Collins offers a compelling vision of the future via a fictional character named Hope, born on January 1, 2000. Collins describes a world where Hope and most other people have had the entirety of their DNA sequenced and integrated with predictive models that make suggestions about diet, lifestyle, and treatments to optimize their health. The result for Hope is a healthy and productive life beyond age 100.

Collins then depicts an alternative world for Hope that looks similar to our own, where a dysfunctional health-care system hasn’t yet integrated personalized medicine. In this dystopia, doctors haven’t been trained in genomics, and payers won’t fund predictive and preventive tests and protocols. Hope, who has a genetic predisposition for heart attack, drops dead while gardening at age 50.

Despite the corny name “Hope,” these pages are the best part of Language of Life: DNA and the Revolution in Personalized Medicine­–along with quick summaries of the promise of stem cell therapies and gene therapies, also included in the final chapter: “A Vision of the Future.”

For me, the rest of the book was less insightful than I had hoped. Collins–a chief architect of the Human Genome Project and now director of the National Institutes of Health–offers a thorough description of current-day genomics. With an easygoing style he describes how genetics is beginning to infiltrate clinical medicine, most significantly for rare diseases caused by extreme glitches in a person’s DNA, such as Tay-Sachs, Down syndrome, and the like.

He writes chapters on how genetics is providing clues for people about whether or not they will experience side effects if they take a drug, and how genetic differences among people are shedding light on common diseases such as diabetes.

This is a useful update on dozens of other books and popular articles about genomics written over the last several years. However, with the exception of those final pages, it neglects to explain why the revolution in personalized medicine presented in “option one” of Hope’s possible futures is taking so long. This leads me to three complaints that I have with Collins’s book.

The first is that The Language of Life shares the tendency of most popular books and media to be overly gung ho about a genomic revolution that for years has been long on promise and short on reality. This lack of success has not come from want of trying. As Collins notes, scientists have made great advances in understanding genomics and molecular biology, while companies have worked hard to translate the wealth of information being generated about our DNA into tests and treatments that will be useful to patients.

Pharmaceutical companies are using molecular biology to design more targeted drugs, and the likes of 23andme and Navigenics are selling genetic testing services online, directly to consumers.

Collins mentions that developing so-called “rational” drugs (based on knowledge of molecular interactions instead of trial and error) has been challenging, and that proffering DNA tests online for diabetes, heart disease, and schizophrenia has been controversial. But he barely mentions that the U.S. Food and Drug Administration has approved only a handful of drugs in the personalized medicine space, or that direct-to-consumer testing has failed to attract many customers.

The latter situation became clear last fall when 23andme cofounder Anne Wojcicki announced at the TED MED meeting in San Diego that her company had sequenced the DNA of only 30,000 people in two years–despite overwhelming publicity that included being named Time magazine’s 2008 Invention of the Year.

This tepid public response might be explained by the still-high cost for genetic testing–which is getting less expensive–or by the fact that these tests have yet to be fully validated as accurate predictors of risk factors for disease. It also may have to do with a public that has yet to see or understand the relevance of DNA testing beyond rare genetic disorders and CSI-style forensics.

I was hoping that Collins would offer a more frank assessment of where we stand on the road to a true age of personalized medicine–what’s worked and what hasn’t.

Which leads to my second issue with The Language of Life–that Collins does not draw on his experience and provide us with a plan for closing the wide gap between our genomic-challenged world and Hope’s hoped-for future.

Collins does outline the bare bones of an agenda for pushing society forward into a true age of personalized health. He calls for an increase in funding for research (not surprising coming from the director of the NIH); better use of electronic medical records to collect data that can be used to develop predictive models for disease; improvements in policy to facilitate a more rapid progression from research to applications for patients; an emphasis on education, especially for physicians and other medical caregivers; and finally, a more robust bioethical discussion about potentially controversial innovations.

I understand the need to keep explaining genomics until the public gets it. And Collins uses his folksiness and charm to great effect as he patiently explains one more time what exactly a nucleotide is, and how having an A rather than a G might predispose one to a high risk for colon cancer. At some point, however, the discussion needs to shift to a realistic blueprint for action. Only then will the public get the lesson–when genetics ceases to be an abstraction and becomes relevant to their lives.

The third gripe I have with the book is its overwhelming emphasis on genomics as being the language of life. I’m surprised by this, given that Collins has championed several programs at the NIH that are trying to integrate genomics with other key components that make a person who they are, and that have powerful impacts on disease, behavior, and other traits.

Chief among these nongenomic influences on human life is a person’s environment–everything from diet to UV rays and chemical toxins such as mercury and pesticides. Each of us is born with a genetic blueprint, but this is meaningless for most common diseases without understanding the interaction of the environment and our personal genetic proclivities for either sensitivity to or protection from assaults from the world we live in.

Collins mentions the role of the environment and other crucial factors that affect our health, including proteomics and the trillions of microbes in our bodies, but only in passing.

In 2006, Collins wrote The Language of God: A Scientist Presents Evidence for Belief, which had the same accessible style as Life. A devout Christian, Collins analyzed and dismissed the arguments of those who deny evolution and who oppose on religious grounds embryonic stem-cell research. Collins said that for him, God and biology are compatible–and that God’s handiwork can be seen in the workings of every cell, nucleotide, and stem cell that scientists work with in their labs.

Collins engaged a wide audience with that first book as it settled onto the New York Times bestseller list for several weeks. In part, this was because of the topic–the eternal tussle to reconcile faith and science. But Collins’s book also resonated because he clearly articulated a path forward for people who were struggling with what seemed to be a contradiction between faith and science.

I’m hoping Collins writes a Language of Life II that takes a similar tack: moving beyond explanation and enthusiasm to also articulate a clear path forward, so that the hope for personalized medicine he describes in those final pages can become a reality.