THREE MONTHS after conception, six months before a child enters the world, there is one aspect of its physical appearance that will never change: the fingerprints. The patterns of whorls, loops and arches, all formed from ridges, reveals who you are. Its image left on a smooth surface can also help to tell a story about what you did.
Eventually, that image might also reveal disease you might later develop and what genetic disorders you might pass on to your children. With that knowledge, you and your physician could monitor your health carefully and look for symptoms of disease early. And in the case of serious genetic disorders, you could decide whether to have children with a better idea of what the potential risks for your offspring are.
The science of studying fingerprints for clues to genetic makeup is still in its infancy. There are those researchers who believe it should stay there
–that dermatoglyphics, as it is called, has been overtaken by sophisticated genetic tests and methods of analyzing genetic material, and that at best it could provide informatiom too sketchy to be truly helpful.
But others, while acknowledging that dermatoglyphics has limitations, see fingerprints as yet another tool in the quest to understand inherited diseases.
Recently, they have found some evidence that they are right. Many victims of Down`s syndrome, a genetic disorder that causes mental retardation, have distinctive fingerprint markings. And preliminary studies point to possible patterns for Alzheimer`s disease and breast cancer.
”The idea is to study subgroups to get some idea if there is any association between dermatoglyphics and some of these diseases,” says Dr. Chris Plato, a geneticist at the National Institute of Aging`s Gerontology Research Center in Baltimore. Plato, who has been collecting and studying prints for more than 20 years, envisions the distinctive patterns as one of many diagnostic and screening tools used to understand disease.
Fingerprints are established during the first three months of pregnancy and do not change throughout life. Everyone has unique fingerprints, even identical twins, because the pattern of lines and whorls is formed by both genetic and environmental factors. Thus, identical twin fetuses that share identical genetic makeup still occupied different spaces in their mother`s womb. And that subtle difference is enough to create a slightly different environment. The blood flow may be greater or less; something may press against the fetus. The result is the one physical characteristic that stamps you indelibly.
”Dermatoglyphics is a mirror of the embryological development,” Plato says. ”If we find an association (between a fingerprint and a disease), it means that it is genetic, or we can say that it happened at this time.”
In this way, fingerprints may help track down the cause of certain birth defects. Scientists suspect that some birth defects have been caused by exposure to chemicals to which the fetus was exposed during the first three months of pregnancy. They could use the fingerprint to see if those affected shared any distinctive characteristics.
When researchers look at fingerprints, they are looking at the patterns of ridges. The points at which three ridges converge are called triradii. The direction of the ridges, the location of triradii and variations in creases in the palms are all potential genetic and developmental markers.
The scientific study of fingerprints began in the early 19th Century, when a Czechoslovakian physiologist named Purkinje published a paper that classified fingertip patterns into nine basis types. Those nine types were very close to the classification system in use today.
After Purkinje, the English scientist Sir Francis Galton was the next researcher to study fingerprints. Galton advanced the science considerably by discovering that fingerprints remained the same throughout life, that patterns were inherited and that different racial groups showed distinctive fingerprint patterns.
In the late 1920s, Harold Cummins made a discovery that propelled the study of fingerprints into the field of clinical medicine. Cummins, who coined the term dermatoglyphics, studied the handprints of children with Down`s syndrome. He found that many Down`s syndrome patients had characteristic patterns called ulnar loops on all fingers and have a high frequency of a type of palm creases called Simian lines and Sydney creases.
Down`s syndrome has a well-defined set of physical characteristics;
fingerprint analysis merely offers corroboration of that. But what Plato and other researchers hope is that it may also be used to screen for genetic disorders early. Thus, if a particular fingerprint pattern were associated with a genetically transmitted disease that appeared later in life, after victims may already have children, the person could decide whether to have children knowing there was a risk of passing on the disease.
Or in the case of some diseases, the distinctive fingerprint might identify a person as having a greater-than-average risk of developing the disorder. Knowing this, they could have frequent checkups and catch the disease in its early stages when it might be more readily treated.
In one pilot study, for example, Plato collected fingerprints from 119 women–34 of whom had breast cancer, 53 who were considered at high risk of developing the disease and 32 who had neither the disease nor an above-average risk of developing it. The investigators found that more than 32 percent of the breast cancer patients had six or more whorls–an usually high number
–compared to 3.1 percent of the normal women. The women at high risk fell in between the two groups.
Studies of patients with Alzheimer`s disease, a neurological disorder that essentially destroys the brains of its victims, have also uncovered possible dermatoglyphic clues. Dr. Herman J. Weinreb, a neurologist at Rockefeller University in New York, studied the fingerprint patterns of 50 patients who had been diagnosed as having Alzheimer`s disease. He compared those patterns with fingerprints from 50 normal adults who were similar to the patients in other respects.
Among the Alzheimer`s patients, he found a ”significant increase” in frequency of a pattern called ulnar loops and a decrease in the number of whorls and arches. Seventy-two percent of the Alzheimer`s patients showed this pattern, compared with 26 percent of the control group.
Much more study will be required to say whether there is indeed a fingerprint marker for these diseases. But if there were, how would physicians use it? In the case of breast cancer, they could alert those whose fingerprints suggested they were at higher risk of getting the disease, who could then have frequent checkups. For Alzheimer`s disease, which is incurable, physicians could use fingerprints as a diagnostic tool to help separate those whose symptoms might resemble those of Alzheimer`s but actually be caused by other treatable disorders.
