Ricki Lewis

Myotonic dystrophy type 1 (DM1), an inherited disease affecting muscles, was one of the first described "expanding repeat" disorders. In these 50 or so conditions, symptoms may appear earlier and worsen from generation to generation, as the mutant gene grows, adding copies of a 3- or 4-base DNA sequence. For many expanding repeat disorders, forty copies seems to be a threshold, causing symptoms when crossed.

In a family with myotonic dystrophy type 1, a grandfather might experience mild weakness in his forearms, while his daughter may have more noticeable arm and leg weakness, slurred speech, and a flat facial expression. Her children have even weaker muscles that contract for too long, creating limitations like being unable to unclench a fist or release a grip.

In MD1, skeletal muscle fibers that contract for too long impair balance and coordination, called ataxia. The condition also causes cataracts, small gonads, frontal balding, fatigue, sleepiness, digestion problems, and cognitive and behavioral impairment. Life may be shortened. MD1 affects about one in 7,500 people, or more than 40,000 people in the US.

To continue reading. go to DNA Science, where this post first appeared.

Monoclonal antibody drugs to fight COVID are being taken off the market while new COVID vaccines are arriving, even as the old ones are standing up quite well against new viral variants. How can two interventions that tweak an immune response have such different outlooks? It stems from the biology.

Understanding what antibodies are, how our bodies make them, and how vaccine and monoclonal antibody technologies work and differ, explains the distinction.

The Antibody Response is Naturally Polyclonal

The immune system is a vast army of cells and their secretions that recognize and respond to the presence of "non-self" cells and molecules, like the spike proteins that fringe SARS-CoV-2, the virus behind COVID. One of the first things I learned in college is that "biology is really chemistry," and that's certainly true for the immune response. It's all about recognizing molecules.

To continue reading go to DNA Science, where this post first appeared.