By sequencing, or identifying, the many telomere patterns and figuring out their behavior, the 44-year-old former Ohio farm boy believes that big dreams might come true: an early-cancer detection test, in-utero screening for heart defects, a way for infertile mothers to jump-start their dying eggs.
"You'd look at patterns between people who grew old and people who died young. You could look at cancer patterns and heart disease," he said.
But before miracles can happen, researchers must know what to look for in the tiny strands - what sequence is out of order, or missing, or mutated. So, under the fluorescent lights on the University of Pennsylvania campus, Riethman's students study the telomere sequences and try to predict what will appear where.
DNA (deoxyribonucleic acid) is made up of a double helix, a sort of spiral staircase in each cell so long that if laid end to end, it would measure two yards. The DNA contains all the information needed for the body's cells to function. There are only four molecules, called nucleotides, used in DNA. There are three billion base pairs of nucleotides, wound up in 46 sets of chromosomes, which appear in the nucleus of every cell.
At the tips of the chromosomes lie the telomeres.
It was July 2000 when researchers announced that they had mapped the human genome, identifying the three billion base pairs that make up human DNA. The hope is that completion of the blueprint will give a great push toward preventing, treating and curing a host of genetic diseases.
In today's edition of Nature, scientists say the number of "blanks" in the map has dropped from hundreds of thousands to 341.
