Scientists identify gene that causes humans to be born with fingerprints

By Mark Waghorn via SWNS

A gene that causes humans to be born with fingerprints has been identified.

It is responsible for the circular, wavy or winding patterns - and also fuels limb development, say scientists.

The discovery could lead to new treatments for congenital disorders - including Down's syndrome.

Fingerprints are best known as a cornerstone of a criminal investigation. They have been accepted as evidence in British courts for 120 years.

The distinctive shapes are unique to every individual. How they form has remained a mystery - until now.

It sheds fresh light on the link between genes and people's observable characteristics - or 'phenotypical traits'.

Co-senior author Professor Sijia Wang, a geneticist at the Chinese Academy of Sciences, said: "We started the work purely out of curiosity.

"But later it turns out fingerprint pattern is associated with genes for limb growth - which are critical for foetal development.

"This provides another classic example of pleiotropy - when multiple phenotypes are interrelated to each other and are affected by the same genes."

The most comprehensive study of its kind scanned the DNA of more than 23,000 people across ethnic groups.

One of the most influential regions for fingerprints regulated the expression of a gene called EVI1 - key to embryonic limb development.

The patterns are generally categorised into three types - known as arch, loop and whorl.

These furrows and ridges begin to appear on a foetus’ fingers and toes after the third month of pregnancy.

It is believed they evolved to help us grab objects - and sense their textures.

Prof Wang and colleagues tested the finding by genetically engineering mice so EVI1 was switched off.

The lab rodents had abnormal skin patterns on their digits compared to wild peers.

Analysis of human data revealed fingerprint patterns are genetically correlated with finger length.

For example, people with whorl-shapes tend to have longer little fingers than those who do not.

Co-first author Prof Jinxi Li, of Fudan University, Shanghai, said: "We don't know exactly how the genes shape fingerprint patterns.

"But it could be determined by the amount of strength from growth that's put on an embryonic tissue called volar pads that plays an important role in the formation of different patterns of fingerprint."

As a foetus' hands grow, the palms and fingers would stretch and elongate. These forces could turn a whorl into a loop, for example, she explained.

Previous research has linked EVI1 to leukaemia. Some studies have also shown people with whorl patterns are more susceptible to the disease.

Prof Wang said: "Many congenital genetic disorders are related to different dermatoglyphic patterns - such as fingerprints."

For example, children with Down's syndrome are more likely to have a single crease running across the palm of their hands.

Added Prof Wang: "Our study suggests fingerprints are affected by crucial development genes, which provides a strong theoretical basis for this kind of pleiotropy."

The study in Cell is part of the International Human Phenome Project. It aims to map how human phenotypical traits are linked.

More research is being planned on how fingerprint patterns relate to diseases and the underlying mechanism behind the phenomenon.