Ricki Lewis

Sailing from New York City to London a century ago took days; today the trip takes hours by air. Similarly, the “diagnostic odyssey” to identify rare diseases has collapsed from years to months, sometimes even less, through the use of exome sequencing and analysis.

A tale of a teen and a tyke with the extremely rare Wiedemann-Steiner syndrome (WSS) argues for the value of earlier exome sequencing in the search for a diagnosis. Read More 

Marc Pieterse was angry.

His son Vincent’s unusual features – long, thick eyelashes; low-set ears; extra teeth; autistic behaviors; brittle hair; flat back of the head; hearing loss; developmental delay – had led Marc, an engineer and self-taught geneticist, to seek exome sequencing. He knew that strange combinations of traits could mean a mutation.

Sequencing Vincent’s exome – the protein-encoding part of the genome – could reveal if a new mutation had arisen in him, rather than having been inherited from his parents. And that’s what happened. Vincent has his own dominant mutation in a gene called RPS23. He isn’t, however, defined by any disease. He’s a striking, active, and happy young teen who loves watching and listening to birds as he rides his mountain bike to school through a nature reserve. Read More 

Genetics is the study of genes, DNA, and variation; heredity is the passing of inherited traits from parents to offspring. Families with one member, typically a child, who has a collection of unusual symptoms that don’t fit any clinical diagnosis may in fact have a genetic disease – but one that arose spontaneously in the child, rather than having been inherited from carrier parents.

Exome sequencing is helping to solve these genetics-but-not-heredity mysteries. The story of one little girl and her father’s efforts to find her mutant gene, and how the tale wove in and out and now back into my human genetics textbook, illustrates the evolution of personalized genomic medicine.

THE BEA PROJECT
When Hugh Rienhoff first saw his daughter Bea, born in December 2003, he knew something was wrong. Her long feet, clenched fingers, poor muscle tone, widely-spaced hazel eyes, and a facial birthmark might have been just peculiarities to anyone who wasn’t also a physician and a geneticist. Read More 

(This blog first appeared at Scientific American blogs on July 29. I have written about the 4 childhood blindness papers for Medscape Today, to be published August 2 or 3.)

On Sunday morning, July 21, I faced a room of people from families with Leber congenital amaurosis (LCA), an inherited blindness caused by mutations in any of at least 18  Read More 

I'm rerunning this blog post from November, because Gavin's mutation was announced today -- the first step towards a gene therapy! Tomorrow I'll run my blog on the discovery that is now on Scientific American blogs.


In a hotel ballroom on the campus of the University of Pennsylvania on a midsummer Saturday in 2010, an unusual roll call was under way at the Family Conference for the
Foundation for Retinal Research. Betsy Brint, co-head of organization, was calling out what sounded like code words – CEP290,  Read More 

10 Things Exome Sequencing Can’t Do – But Why It’s Still Powerful

Sequencing of the exome – the protein-encoding parts of all the genes – is beginning to dominate the genetics journals as well as headlines, thanks to its ability to diagnose the formerly undiagnosable.

The 2011
Pulitzer Prize in Explanatory Reporting honored the Milwaukee-Wisconsin Journal Sentinel’s coverage of a 4-year-old whose intestinal disorder was finally diagnosed after sequencing his exome.  Read More