CRISPR Continues to Cut Impressive Numbers in Beta-Thalassemia, Sickle Cell Disease, and More

A year ago, Paddy Doherty’s doctor told him that he had a rare hereditary disease called transthyretin (ATTR) amyloidosis, the same disease that had killed his father.

As reported in a recent article by the Washington Post, Paddy recalled that although his father had been physically fit all his life and worked at construction projects well into his sixties, he began to have difficulty breathing on their long walks in the Irish countryside.

Doctors attributed his father’s shortness of breath to angina resulting from an underlying problem with his heart.

Now it was Paddy’s turn. Last February, at age 65, Paddy began experiencing similar breathing problems. He was an experienced hiker, having managed the Himalayas, but he was getting winded when he attempted local inclines.

Tests confirmed ATTR amyloidosis.

At the time his father was diagnosed there were no effective treatments for the disease. This time Paddy’s doctor, nephrologist Julian Gillmore head of the ATTR Centre at the University College of London, was able to offer Paddy a chance for a cure with CRISPR gene editing.

Paddy participated in one of the first clinical trials investigating CRISPR genome editing therapy.

He reports that he did not experience any side effects and was back home in two days. And that walk that left him out of breath? It’s now his Sunday ritual.

About ATTR Amyloidosis

Roughly fifty-thousand people worldwide are affected by ATTR amyloidosis in its hereditary form. Many patients are clustered in the county of Donegal Ireland.

ATTR amyloidosis is a protein misfolding disorder. The protein, called transthyretin (TTR), is produced by the liver. TTR may become unstable and break apart, forming clumps in the heart, nerves, and various other locations in the body. When the protein builds up in the heart it interferes with the heart’s normal function and can be life-threatening.

Dr. Gillmore further explained that if ATTR amyloidosis is left untreated, the patient may develop low blood pressure, bowel disturbance, and heart failure.

About CRISPR

CRISPR offers a new and unique treatment for rare diseases as it enables researchers to change the DNA of living beings. While numerous studies investigating CRISPR’s effect on rare diseases continue, initial findings have been promising thus far.

CRISPR, genetic scissors, are capable of repairing, inserting, or editing genes that can rewrite the code of life.

When applied to nonhuman applications, CRISPR has been noted for creating crops that are resistant to disease, new antimicrobials, and laboratory animals that are genetically modified.

CRISPR is made up of two molecules that are inserted into the bloodstream or cells. The first molecule is a protein called Cas9 that acts like scissors. The second molecule is a guide RNA that brings Cas9 to the correct target in the genome.

As a measure of CRISPR’s success, the two women who were responsible for developing CRISPR were awarded the Nobel Prize for Chemistry.

Dr. Gillmore and other researchers are actively working to develop CRISPR therapies for Duchenne muscular dystrophy, cystic fibrosis, Huntington’s disease, and other conditions that occur due to mutations in single genes.

CRISPR Therapeutics and Vertex Pharmaceuticals recently reported data from clinical trials that tested CRISPR therapy on beta-thalassemia and sickle cell disease.

All fifteen beta-thalassemia patients no longer needed blood transfusions. The seven sickle cell patients no longer had blocked blood flow that had caused emergency visits due to extreme pain.

Both disease groups continued to see improvements at the twenty-sixth-month follow-up.