Progeria?
- Literature - The Genetics of Progeria
The Genetics of Progeria
Biol. 2402 - Anatomy & Physiology
Richland College, Spring 2001 Class Project
Web Project Members: Megan Gardner, Lindsey Leger, Stacie Stricklin
Progeria has been determined to be genetic, that is, the disease is passed along during cell division in the formation of a fetus. The disease is not necessarily hereditary because parents of children with progeria are not affected, nor do they carry a gene for it. We know this because of recent analysis that has been done on the chromosomes of genes with people affected by progeria. There is an inverted insertion in the long arm of Chromosome 1 in 70% of the cells studied. This evidence suggests that the gene for progeria is located on Chromosome 1. The gene is not necessarily one that is passed down from parent to child, but rather is a normal chromosome contributed by each parent that mutates during cell division. That mutation is then replicated during subsequent divisions. The cause for this mutation is unknown.
This mutation was first suggested to be autosomal recessive based on studies done between 1920 and 1960, however studies done in the 1970s show the mutation is autosomal dominant. This finding means that the mutation occurs on only one of the two chromosomes in the pair, rather than on both chromosomes like a recessive mutation would suggest. It has been suggested that the gene for Werner’s Syndrome lies on Chromosome 8, but further evidence is needed to verify this.
There is usually no family history of progeria or Werner’s syndrome in families of affected individuals. Since neither parent carries or expresses the gene, each case is seen as a random, isolated mutation. It is unlikely to have more than one child in a given family affected with progeria because of the rarity of the disease. However it is possible to have identical twins that are both affected with the disease. But because each case is a new sporadic mutation, it is also possible to have one twin with progeria and one without the disease.
There are three main theories as to why progeria occurs. They are:
- Helicase Theory
- Mutant Gene Theory
- Telomere Theory
Until more research can be done on the genetic basis of progeria and Werner’s syndrome, the cause will remain a mystery. Without further evidence to support any of the proposed theories, efficient treatment and prevention can not be administered. More research is in progress, but our lack of understanding about the disease slows the process. With advances in technology comes more opportunity to finally locate and understand the affected gene or genes that cause progeria and steps toward finding a treatment, cure, and preventative measures can be taken.
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