(RxWiki News) New genome sequencing techniques have helped researchers successfully analyze TTN, the largest gene in the human genome. They've found that mutations in this gene are linked to a common type of heart failure.
Investigators have only recently been able to sequence the gene in a large number of patients because of the enormous size of TTN.
"Talk to a cardiologist about your risk of developing heart failure."
Their recent genetic study revealed that mutated TTN genes can lead to structural deformations in heart muscle fibers, which can cause dilated cardiomyopathy, a type of heart failure in which the heart becomes weakened and enlarged.
Dr. Christine Seidman, Cardiovascular Genetics Center director for Brigham and Women's Hospital, noted that diagnosing any disease early, including dilated cardiomyopathy, can allow for treatments to prevent devastating outcomes such as sudden cardiac death from an abnormal heartbeat or the development of heart failure.
She said that by realizing that TTN mutations account for a substantial amount of idiopathic dilated cardiomyopathy cases, doctors will have the opportunity for early diagnosis in at-risk individuals, including those with a family history of the heart disease.
During the study investigators analyzed genetic samples from 312 individuals diagnosed with dilated cardiomyopathy, 231 with another heart muscle disease called hypertrophic cardiomyopathy in which the heart muscle thickens, and 249 who did not have heart disease.
They pinpointed 72 mutations in the TTN gene that suggested encoded proteins had been shortened. When the proteins are shortened, they lack a particular region that helps regulate the production of force in heart cells.
Researchers also found additional mutations among patients with dilated cardiomyopathy as compared to healthy patients and those with hypertrophic cardiomyopathy, which suggested that the TTN mutation caused dilated cardiomyopathy, but rarely caused hypertrophic cardiomyopathy.
The outcomes of patients with dilated cardiomyopathy were found to be similar regardless of whether a patient had the gene mutation. Researchers did note, however, that adverse events such as heart transplants or death tended to occur sooner in men as compared to women.
The study will be published in the Feb. 16 issue of The New England Journal of Medicine.