DR ANJU BATTA SEHGAL
Scientist are working to forestall aging, not in the fountains of mythical spring, but rather in understanding the molecular changes associated with aging process. Curiously their findings has led to search of small group of special children, who experience, not perpetual youth but alarmingly premature old age. It was first noticed by an English physician, Jonathan Hutchinson, who published a report in 1886 of a young patient who was bald with aged facial features and stiffness of joints. Another physician, Hastings Gilford in 1897 studied an additional case of disorder, giving it the name “Progeria”, derived from the Greek word for “prematurely old.”
Disease is exceedingly rare, known popularly as Hutchinson-Gilford Progeria Syndrome (HGPS), affects about 50 children worldwide. Hutchinson and Gilford reported it around 100 years ago. Children with the disease appear healthy at the time of birth but by 2 years of age start showing accelerated aging, including cessation of growth, hair loss, aged skin, stiffness of joints, heart disease and osteoporosis. Maximum life expectancy is upto 14years of age. Many out of them die due to coronary heart disease. HGPS is a genetic disorder usually inherited as an autosomal dominant trait. In 1998, Leslie Gordon and Scott Bern’s 2 year old child was diagnosed with HGPS. Both were physicians, they started gathering information about this disease, but non existed. They established Progeria Research Foundation. In 2003 the gene that causes the disease was identified.
HGPS results due to mutation in `a gene called `lamin A (LMNA). Which is located on human chromosome 1. Protein normally encoded by LMNA helps to form an internal scaffold that supports the nuclear membrane of the cell. The specific mutations that cause HGPS produce an abnormal truncated form of lamin A protein which disrupts the nuclear membrane in unknown way, results in premature aging.
The findings that mutations in LMNA cause HGPS hints that the architecture of nucleus may play role in normal aging. The relation between lamin A protein and normal aging is still not clear. Research on patients with HGPS may lead to a better understanding of how we all change with age. By mutation an abnormal form of the lamin A, protein called progerin is produced and makes cells unstable. This appears to lead to progeria’s aging process. Unlike many genetic mutations, progeria is rarely passed down in families. The gene mutation is a rare, chance occurrence in the majority of cases. There are no known factors, such as lifestyle or environmental issues, which increase the risk of having progeria or of giving birth to a child with progeria.
Progeria is extremely rare. For parents who have had one child with progeria, the chances of having a second child with progeria are about 2 to 3 percent. Other health problems frequently associated with aging — such as arthritis, cataracts and increased cancer risk — typically do not develop as part of the course of progeria.
A young girl with progeria (left). A healthy cell nucleus (right, top) and a progeria cell nucleus (right, bottom)
(The author is ex Principal NSCBM Govt. College Hamirpur, Himachal Pradesh and former Professor of Botany)
