Why it matters

The new study explains a longstanding puzzle in medicine: why do some people who’ve inherited a disease-causing mutation experience fewer symptoms than others with the same mutation? “In many diseases, we’ll see that 90% of people who carry a mutation are sick, but 10% who carry the mutation don’t get sick at all,” says Bogunovic, a scientist who studies children with rare immunological disorders at Columbia University Irving Medical Center.

Enlisting an international team of collaborators, the researchers looked at several families with different genetic disorders affecting their immune systems. In each case, the disease-causing copy was more likely to be active in sick patients and suppressed in healthy relatives who had inherited the same genes.

In a groundbreaking study, scientists have discovered a way to manipulate the very fabric of life by using light to reshape DNA strands. This innovative approach provides new insights into the material properties of chromosomes, unlocking potential advancements in understanding gene expression and developing treatments for genetic diseases.

Chromatin, the material that makes up chromosomes, is a complex structure where long strands of DNA are wrapped tightly around proteins. Despite its compact nature, chromatin must unfurl in certain regions to allow cells to access and replicate genetic information.

Some areas remain rigid and coiled, silencing genes, while others are flexible and accessible, facilitating gene expression. This duality has led scientists to question whether chromatin behaves like a solid, a liquid, or a hybrid of both.

Summary: New research reveals that certain cells inactivate one parent’s copy of a gene, leading to a bias in gene activity that may explain why some individuals with disease-causing mutations remain symptom-free. This selective gene inactivation, known as monoallelic expression, affects about 1 in 20 genes and varies between cell types.

The study shows that in families with genetic disorders, the active copy of a gene often determines disease severity. These findings challenge traditional genetic paradigms and suggest new approaches to diagnosing and treating inherited diseases.