No effective treatments are known, although scientists reported last September that a drug currently being tested against cancer might help the patients. 

The cause of the condition, too, remains unknown. But researchers reported one breakthrough in 2003. They traced the condition to a spontaneous mutation in a gene encoding a component of the cell nucleus, the compartment of a cell that stores our genes. 

The nucleus must keep this DNA safe but accessible inside a strong protective envelope. Tough but adaptable molecules called lamins line the inner membrane of this envelope. The progeria mutation causes a defect in one type of lamin, called nuclear lamin A, causing cells to age rapidly.

This left researchers asking: what is it about this defect that causes cells to age so rapidly? And might it have some relevance to normal aging? In other words, is progeria a warp-speed version of normal aging?

In research presented Tuesday at the Annual Meeting of the American Society for Cell Biology in San Francisco, Robert Goldman and collaborators at Northwestern University and elsewhere said they’ve made some headway into the first question at least. 

Lamins link together into fibrous structures that hold up the “walls” of the nucleus. They also serve as an internal scaffold for the complex machinery by which our genes copy themselves and direct the working of our bodies, a process called gene expression.

Reporting on two studies, Goldman and colleagues said the mutant lamins seem to disrupt key controls of both these processes.

One study found that some of the lamins turn up in the wrong place—too tightly linked to the membranes of the nuclear envelope to participate properly in key stages of cell replication. 

The researchers said this would disrupt DNA replication, and be a likely factor in the rapid march of cells toward premature “senescence,” a cellular version of aging. Whether similar missteps and miscues by nuclear lamins are part of normal human aging is the question that draws researchers onward, said Goldman. But the findings are consistent with a widespread belief among biologists that a key cause of ordinary aging is damage to DNA and mistakes in gene replication, two interrelated problems.

Another study found that the most common type of mutant lamin re-organizes regions of chromosomes that are key in controlling gene expression. These portions of chromosomes, known as heterochromatic regions, are kept inactive for various reasons; for example, one of the two female X chromosomes is deactivated in this fashion in order to avoid having them duplicate their work. 

One of the hallmarks of the X chromosome heterochromatic region is that it is linked to molecules known as methylated histones. But the researchers found that in a girl with the progeria syndrome, the quantities of these molecules and of an enzyme required to form them were abnormally low.

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