Gene Discovered in Mitral Valve Disease

Study: 'Close but No Cigar' A study has discovered a gene present in adult patients diagnosed with mitral valve prolapse.

It's not a new study -- 2005 -- but it's new to me. I read everything I can get my hands on about the disease. There has yet to be a comprehensive one done with dogs. I do know from reading about the disorder in canines, from what literature is out there, that it's found more often in certain breeds and that it's considered genetic. Mia's vet told me it's sometimes seen in overbred dogs, which makes sense with Mia, since she's a full long-haired Chihuahua.

It's also widely seen in the Cavalier King Charles Spaniel. mitral valve disease in these dogs has shown them to have lifespans of just one to three years. Not good statistics. In other breeds, especially the smaller ones, like Mia, the disease doesn't cause early death because it often doesn't develop until they're older. In Mia's case, however, she developed it young. She was rescued from the storm water in New Orleans when she was only 2 or 3. Now she's around 5 or 6 years old.

We knew when Mia was first examined at the triage center that she had a heart murmur. Little dogs often do. But it's most often because of innocent flow murmurs, not MVP. Then, when she became lethargic (as described in an earlier blog post, below), I took her to the doctor and ultrasound and radiographs were done, and that's when we learned the sad news. She received a Grade 5 (V) -- graded from 1 to 6 -- which meant her murmur was quite loud, with the vibration felt with fingertips without a stethoscope and with a precordial "thrill." Not good. The latest gene study, however, gives me hope, because they've isolated the gene, which means we now know what the tissue consists of and, for Mia, what supplements she can take to help her valve tissue heal. In the meantime, I'm still doing CoQ10 enzyme therapy, along with other supplements, to keep her ticker ticking. To sum up, here are the words from Dr. J Am Coll Cardiol from the American College of Cardiology Foundation:

"Having identified 3 chromosomal loci for mitral valve prolapse does not in itself load the train with genes, but it does suggest that the caboose is waiting to hitch it," the study says. "Let us hope that with our ability today to rapidly sequence DNA and evaluate new candidate genes we will enable the train to leave the station soon."

Photo, by Cathy, of Mia sleeping, with Lois Lane (a chihuahua puppy who was with Mia and me for two months), under the desk in Tylertown, Mississippi, at the triage center for Katrina pets.