Fingerprints, long used to solve crimes, may also help track down people at risk of diseases before any symptoms appear.
New research suggests that women with specific types of fingerprints — namely fewer loops and more arches — may be more at risk of developing gynaecological cancers.
Previously, researchers have suggested there may be links between fingerprints — and equally unique palm prints — and the risk of conditions as diverse as diabetes, Alzheimer’s, leukaemia, impotence, depression and even gum disease.
The theory behind dermatoglyphics — the scientific study of fingerprints and disease links — is that if the growth of limbs, organs or other tissues is disturbed in very early foetal life, there will also be changes in the configurations of finger and palm prints.
These changes, it is argued, are therefore visible and permanent markers of abnormal development in the nervous system and other areas that are developing in the womb at the same time.
Our fingerprints, the tiny ridges and troughs in the skin, are unique. Although identical twins share DNA, no two people have ever been found to have the same fingerprints.
Each unique pattern is produced by a combination of effects on the foetal fingers in the womb when they are formed between the 11th and 24th week of pregnancy.
The environment in the womb is influenced by factors including blood pressure, hormonal mix, maternal diet and any infections, the position of the foetus in the womb and the density of amniotic fluid around the foetal fingers — these, as well as genes, are thought to play key roles in determining each individual pattern.
There are three main patterns: whorls, arches and loops (see box, right), and it is the number of these plus shape, size and spacing that makes everyone unique.
Some of the potential links to health include:
Heart disease: Men with coronary heart disease (CHD) are more likely to have a particular type of fingerprint pattern, according to a 2015 study in the Journal of Clinical and Diagnostic Research. Scientists compared 250 men with and without CHD and found those with the disease had more ridges in specific areas, and different whorl patterns.
"Factors arising in the critical period of pregnancy may affect the development of the heart and the ridges of fingers and palms," say the researchers from Ningxia Medical University, in China.
Cancer: Links between fingerprints and a number of cancers, including breast, prostate, ovarian and cervical, have been reported.
In the latest study, researchers examined the fingerprints of 300 women with ovarian and other gynaecological cancers and compared them with those of healthy women.
The results, reported last year in the European Journal of Obstetrics & Gynecology and Reproductive Biology, showed that women with cancer tended to have fewer loops in their fingerprints. They also had a higher number of arch patterns.
The researchers from Tehran University of Medical Sciences, Iran, also analysed previous research on breast cancer, revealing a higher percentage of arches in cancer patients’ prints.
The researchers suggested that fingerprints could be "a cheaper and faster method for screening large numbers of people".
In another study, doctors at University Hospital Zagreb, in Croatia, found that people with cancer of the pituitary gland have fingerprints with a smaller number of ridges in specific areas, according to a 2016 report in the International Journal of Environmental Research and Public Health.
Commenting on the findings, Alan Doherty, a consultant urologist and clinical director of the Birmingham Prostate Clinic, said: "Fingerprints are genetically determined. Cancers develop when there are genetic defects, so it’s not surprising that there may be links."
The possibility that a fingerprint might give the clinician an insight into the risk of being diagnosed with prostate cancer is obviously exciting.
"We look forward to further studies to clarify the role of fingerprints to help in early diagnosis."
Diabetes: Genes and environmental influences are thought to be involved in the development of diabetes, and researchers have found significant differences in the left and right-hand fingerprints of people with both type 1 and type 2 diabetes.
Fingerprints on the left and right hands are not the same but greater left-right differences are likely to be apparent in people with diabetes, researchers at Ohio University in the US discovered in 2017.
Their study of 300 people was the first to show this, and they say it could be used to predict the risk of people developing diabetes.
The research also pinpoints the time in the womb at which diabetes risk increases. The biggest differences in print patterns were found in the fourth fingers, which develop between the 14th and 16th week of pregnancy.
The Ohio team are now working on creating a mobile phone app to identify at-risk individuals before they develop symptoms.
Gum disease: Children with bad teeth have different fingerprint patterns from those who don’t, according to a study in the Journal of Contemporary Dental Practice.
Researchers from Pacific University, in India, compared the fingerprints of 400 children aged five to 12 against their teeth. The results showed that those with bad teeth had more whorl patterns and fewer ridges in their fingerprints.
Multiple sclerosis: This condition is caused by damage to the myelin sheath, the protective covering on the nerves. Although the cause is unknown, variations in dozens of genes are thought to be involved, as well as environmental factors including lack of exposure to vitamin D.
In a 2014 study, researchers compared fingerprints of 120 people, some of whom had MS, and found that they had more ridges. The Turkish study, reported in the journal Neuroscience, also found more loops in the left hands of MS patients.
Asthma: Genes and the environment are thought to play a role in the development of asthma. Several studies have found differences in fingerprints between people with the condition and those who don’t have it.
In the latest research, reported in 2016 in the International Journal of Healthcare and Biomedical Research, patients with asthma had significantly fewer arches and a greater number of loops.
Infertility: When researchers compared infertile men’s finger and palm prints, they found they had a significantly lower number of loops than a control group, reported the Nepal Medical College Journal in 2013.
Professor Raj Persad, consultant urologist with Bristol Urology Associates, said: "There is scientific rationale to link any genetically determined feature such as fingerprints with other genetically determined characteristics, such as specific types of infertility."
But compiling a database would be a mammoth task and rigorous testing would be needed, there’s more to it than simply saying 'significantly lower number of loops'.