Stories about: telomeres

Short telomeres, myriad diseases: The complex mystery of dyskeratosis congenita

dyskeratosis congenita
The chromosome tips known as telomeres can be compromised by many different mutations — with many different effects. (vitstudio/Shutterstock)

Genetic diseases largely fall into two overarching camps. You have simple, single-gene alterations that produce a single, recognizable disease. And you have conditions like diabetes or cardiovascular disease, where many variations in many genes all make small contributions that fuel the illness.

Dyskeratosis congenita (DC) doesn’t fit either profile. While this rare genetic condition manifests in certain predictable ways (bone marrow failure among the most common), there is huge variability between patients. Yet genetics has revealed one common thread: the molecular caps that protect the ends of chromosomes, known as telomeres, are shortened in DC patients. This results in cells that age too quickly.

From there things get complicated, because problems with any of 11 different genes can trigger short telomeres in DC. And DC, it appears, is only the beginning.

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Does autism stress families’ chromosomes?

telomeres autismThe ends of our chromosomes have little caps called telomeres that keep our DNA from degrading as our cells divide. Telomere length is partly determined by genetics. However, telomeres also shorten as we age and as a result of health conditions, including stress—as in institutionalized children in Romania and women caring for children with chronic illnesses.

An intriguing new study in the July Journal of the American Academy of Child and Adolescent Psychiatry finds shortened telomeres not just in children with autism (confirming a recent study from China) but also in their infant siblings and their mothers. An effect was also seen in fathers, but it didn’t reach statistical significance.

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Predicting cancer drug response: One or two genes don’t always tell the story

Measuring the total amount of DNA damage within a tumor’s cells could help doctors predict its vulnerability to drugs like cisplatin. (Haukeland universitetssjukehus/Flickr)

Drugs like cisplatin that break DNA are some of the strongest weapons we have against breast, ovarian and other cancers. The problem, common to every form of chemotherapy, is that cisplatin doesn’t work for everyone. Given the potential side effects that go along with the drug—including vomiting, hearing loss and muscle cramps, just to name a few—the decision to give it to a patient becomes something of a gamble: Does the benefit outweigh the risk?

There are tests that examine individual genes and which can give doctors a limited view as to which tumors might respond best to cisplatin. But a multicenter team co-led by Zoltan Szallasi, MD, of Boston Children’s Hospital’s Informatics Program (CHIP), thinks they may have a solution that looks beyond individual genes to see which tumors might succumb to cisplatin and other drugs like it.

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