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Genetic Linkage

Tale of Two Families: Exome Sequencing and Faster Diagnosis of Rare Disorders

Exome sequencing significantly sped diagnosis of Nicholas' rare genetic syndrome.
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 
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Hannah’s 2016: From Curling Toes to Gene Therapy

Hannah Sames will have gene therapy in March, after an 8-year effort from her family. Go Hannah!
Eleven-year-old Hannah Sames can still curl her toes, just barely. But time is running out.

If Hannah can move her toes for a few more weeks, until she becomes the fourth child in a clinical trial for gene transfer to treat giant axonal neuropathy (GAN), the disease might halt – she may even regain function, as mice did.

It’s been an 8-year wait. So Facebook friends call 2016 “Hannah’s year.”

The first sign that something was amiss  Read More 
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Juvenile Huntington's Disease: The Cruel Mutation

Jane and Karli Mervar
Looking back, signs that Jane Mervar’s husband, Karl, had Huntington’s Disease (HD) started about when their youngest daughter, Karli, began to have trouble paying attention in school. Karl had become abusive, paranoid, and unemployable due to his drunken appearance. The little girl, born in September 1996, was hyperactive and had difficulty following directions. When by age 5 Karli’s left side occasionally stiffened and her movements slowed, Jane began the diagnostic journey that would end with Karli’s diagnosis of HD, which had affected the little girl’s paternal grandmother.

Soon Karli could no longer skip, hop, or jump. And new troubles emerged. Read More 
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Rare Diseases: Unicorns, Not Zebras

The past and future of gene therapy: Corey Haas and Hannah Sames autograph books at the Schenectady Library.
“When you hear hoofbeats, think horses, not zebras.”

Every doctor-to-be hears this mantra. Rare Disease Day, February 28, celebrates the 7,000 or so diseases that are zebras, each affecting fewer than 200,000 people.

Giant axonal neuropathy (GAN) isn’t a zebra, but a unicorn. Eight-year-old Hannah Sames inherited one mutation from each of her parents in a gene that encodes a protein called gigaxonin. As a result, the axons of her motor neurons are slowly filling up with haphazardly-arrayed intermediate filaments. The cells bulge, blocking the messages to her muscles. She’s one of only 50 in the world known to have GAN. But if all goes according to schedule, Hannah and several other youngsters are going to have gene therapy to correct the disease. Read about it at Hannah’s Hope Fund.

Two years ago, at the annual meeting of the American Society of Gene and Cell Therapy in Washington, I had the honor of watching Hannah’s marvelous mom Lori as she watched a child helped by gene therapy – Corey Haas, whose story bookends a brief history of the technology in "The Forever Fix: Gene Therapy and the Boy Who Saved It".

Here’s an excerpt, for Rare Disease Day. Read More 
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Rare Diseases: 5 Recent Reasons to Cheer

3-year-old Gavin Stevens is at the center of one of four papers just published in Nature Genetics about the discovery of a childhood blindness gene.
(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 
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Non-PC Genetics Lingo

We are all people of color, except the Invisible Man and Woman.
I struggle to stay politically correct when updating my human genetics textbook. “Hemophiliac” became “person with hemophilia” and “victim” vanished several editions ago. In the current incarnation, “mentally retarded” became “intellectually disabled” after colleagues warned that  Read More 
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Gavin's Story: Whole Exome Sequencing Finds Mystery Mutation

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 
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