Progeria?
- Literature - Progeria: A Paper by Debra Horng
Progeria: A paper by Debra Horng
Genetics and Embryology, 6.0
19 March 1999
I think progeria is a fascinating disease. This in my written-in-two hours research paper on progeria for my gen/emb course. The “Online Resources” part was not explicitly part of the paper but I used it in my research process.
Jonathan Hutchinson and Hastings Gilford, both English surgeons, described the symptoms of progeria independently in 1886 (Wynbrandt 257). Thus, an alternate name for progeria is Hutchinson-Gilford syndrome. Hutchinson invented the shorter term progeria, a combination of Greek words meaning “prematurely old” in 1904. Since then, in excess of 100 cases of progeria have been recorded worldwide. Scientists have hypothesized that a genetic mutation during conception is the cause of the disease, but they are not sure how to cure the disease.
Individuals affected by progeria have symptoms appearing to correspond to natural old age in childhood and early teens; “progeria… prematurely ages children. Their skin becomes dry, their muscle atrophy and they suffer from atherosclerosis and other diseases normally associated with older people” (Klimbo B-1). There are other symptoms of progeria besides an aged phenotype: “dwarfism, a pinched nose, small face and small jaw (micrognathia), delayed tooth formation and aged-looking skin. Intelligence is normal or above average. The voice is thin and high-pitched. Sexual maturation does not occur.
Richard Allsopp and his coworkers found in 1992 that the cells of children with progeria have shorter telomeres than the cells of unaffected individuals of comparable ages (Lewis982). Teomeres are repeats of the sequence TTAGGG on the ends of a chromosome (Shay 153). Bits of them are removed every time the chromosome goes through mitosis, limiting the number of times a normal cell may divide. Once the amount of telomeres on the tip of any chromosome reaches a certain paucity, the chromosome will not divide any more times. A shorter than normal telomere entails less times a cell may divide and therefore a faster than normal aging process. Although the victims of progeria have shorter telomeres on the tips of their chromosomes in every cell, not all early-aging diseases have telomeres of similar length: “in other aging-genetics disorders, such as Werner’s syndrome and Down’s syndrome, cells lose [normal-sized] telomeres at two to three times the rate in age-matched controls (Shay 153). There is no proven curative treatment at this time for progeria, although there are some treatments to ameliorate the victims’ suffering. Because victims’ relatives of the first degree rarely have the disease and there is a low incidence of consanguinity among the parents of the affected children, scientists believe that progeria is an autosomal dominant trait; also, since progeria in children appears to be associated with an increase in paternal age, cases of the disease most likely arise from a mutation during conception of the child (Wynbrandt 257).
There is not a definitive diagnostic test at the present, so doctors may diagnose cases solely based on phenotypes. The typical age of diagnosis is two, by which time the skin has dried and the individual does not achieve the normal weight (Wynbrandt 257). There is currently no available prenatal diagnostic test. The treatments used for progeria patients include growth hormone injections derived from calf fetuses known as Fibroblast treatments. Although they do not cure the disease, they do improve the quality of life for the victim (Samolinski 1). Guadalupe Flores mother of progeria victim Susanna Navaro of Mexico, says that Susanna’s injections help: “She receives them once a month and right before it’s time for another injection she becomes lethargic and loses her appetite… it also helps with bone aches” (Samolinski 1).
Progeria occurs in approximately one in 8 million children (Klimko B-1). As of June 1998, there are thirty-one people in the world with the disorder. Although it is a relatively rare disease, its effects are drastic. The Sunshine Foundation sponsors an annual reunion for families of children with progeria to congregate in Lake Wales, FL.
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