Progeria: The Causes, Symptoms, and Treatment

Progeria, meaning “prematurely old” in Greek, is a rare genetic disease in which young children seem to age rapidly and is caused by a mutation in the LMNA gene. Around 1 in 8 million babies are born with Progeria all over the world. The progression of this disease is comparable to aging at a rate about six to eight times faster than normal aging. Symptoms of this condition present in early childhood and include failure to grow and skin conditions. Later, a distinctive appearance, including a small face, pinched nose, loss of hair and a fragile body, arises. With time, this disease causes cardiovascular problems and patients usually die of heart disease in their early teenage years.

Progeria is caused by a mutation in the nuclear lamina. Lamins form the nuclear lamina, which is the inner side of the nuclear envelope and the peripheral chromatin. There are four major lamin proteins: lamins A, C, B1, and B2. These proteins aid in many nuclear processes such as chromatin structure, regulation of gene expression, apoptosis, cell cycle regulation, nuclear migration and protein degradation. Because these proteins affect so many diverse cell functions, mutations can result in widespread problems.

Problems arise in a mutation in the LMNA gene. This gene, located on the first chromosome, usually produces Lamin. A de novo point mutation (meaning a mutation that has spontaneously occurred and has not been passed down) replaces cytosine with thymine in position 1824 of the LMNA gene. The mutation creates a DNA splice site where there usually is not one. This creates a problem with DNA transcription and edits exon 11. The change in DNA information eventually produces a mutant protein, known as Progerin, which is lipidated, or gains hydrophobic molecules. This protein is then incorporated abnormally into the nuclear lamina and the nucleus becomes unstable with the addition of this malformed protein. The collection of defective proteins can lead to mechanical issues, overgrowth or loss of lamina, and DNA damage. By changing one nucleotide in the genetic code, an essential protein cannot be produced, altering the organism in drastic ways.

Ongoing research into causes and cures of Progeria may not only help those affected by this disease but also sufferers from closely related diseases such as Emery-Dreifuss muscular dystrophy and Restrictive dermopathy. Another benefit of this research is also information gained about cardiovascular disease and normal aging. In 2003, Swedish scientists discovered the mutant protein, Progerin, in both patients with Progeria and in normal cells but in varying levels. As the normal cells aged, Progerin built up in these cells. This evidence shows a direct link between Progeria, this mutated protein, and old age. The study of Progeria can give us valuable insights into the natural aging process.

One hope for treatment of Progeria is inhibition of protein farnesylation or lipidation process. Through the use of farnesyltransferase inhibitors (FTIs), damage to the nuclear lamina can be blocked. These cells might even be able to be repaired through this treatment, which is a great breakthrough since patients are not usually diagnosed with Progeria until after the damage has already begun. FTIs also appear help to repair nuclei shape and return it from its convoluted form. There is much excitement and hope surrounding FTI treatments because of their predicted medical benefits for both Progeria and coronary artery disease.

Progeria is caused by a single point mutation and the loss of 50 amino acids. Although this is small in the scheme of genetic codes, this small change has dramatic effects. Unfortunately, symptoms associated with old age and cardiovascular problems ensue and usually lead to an untimely death. Progeria is a genetic disease cause by a mutation in the LMNA gene that leads to premature aging and sequentially to death.