There are only about two dozen people in the world who do not have a papillary pattern either on their fingers and toes or on their palms. The phenomenon of the absence of fingerprints was discovered 20 years ago, but the reason why a person's fingertips can be completely smooth has only now been discovered
A group of geneticists led by Tel Aviv University professor of dermatology Eli Sprecher has solved this mystery of nature. After all, the papillary pattern is a "biological passport", it is unique for every person on the planet (even identical twins have different patterns on their fingertips). Scientists are still very vague about why nature needed such an "identifier" at all, and how this pattern is formed.
It was hypothesized that the pattern was needed to improve the grip between the pads of the fingers and objects, then it was replaced by the assumption that the papillary pattern reduces friction. Scientists are now inclined to believe that these curls and combs, unique to everyone in the world, increase the sensitivity of the fingers, but the fact that people meet without any hint of this very pattern has become the main mystery for scientists.
More recently, Israeli geneticists managed to "catch" the gene responsible for such "tricks". It turns out that two extremely rare genetic diseases - Negeli syndrome and reticular pigmentosa dermatopathy - arise from a specific defect in one of the proteins, namely keratin-14. These congenital genetic aberrations cause cell death in the outermost layer of the skin. As a result, people with this genetic defect are born without a papillary pattern on their fingers, toes, palms and feet, according to the American Journal of Human Genetics.
According to Sprecher, “the phenomenon of adermatoglyphia (lack of a papillary pattern) was discovered thanks to five families from Switzerland, all of whose members do not have these patterns. We studied in one of these families the genetic profile of each family member in three generations. None of them had a papillary pattern. And each had a mutation in the SMARCAD1 gene.
Apparently, it is this gene that influences the formation of the papillary pattern during fetal development of a person,”reports New Scientist. In people without prints, this gene mutates. The mutation leads not only to the absence of a pattern, and as a result, to the lack of sensitivity of the fingertips, loss of touch, but also to other anomalies. In particular, people suffering from this disease do not have sweat glands. Also, in such patients, the skin of the palms and feet thickens, and other diseases of the tissues of the teeth, hair and skin may develop.