A marker on the fingertips present at birth may predict adult-onset diabetes, according to a study published in the International Journal of Epidemiology [1].

Dermatoglyphics, the study of skin markings made by ridges on hands and feet, is used as a way of measuring gene expression determined by the early pre-birth environment. On each fingertip, the number of dermal ridges (the ridge count) provides a measure of fingertip growth activity during the early foetal period. These dermal ridges are formed during gestational weeks 12–19, and the resulting fingertip ridge appearance (i.e., the fingerprint) is fixed permanently.

Changes in the uterine environment can influence the activity of genes which either stimulate or inhibit growth of specific areas of the body. According to the study by Kahn and colleagues, those with specific dermatoglyphic patterns were more likely to develop type 2 diabetes after the age of 50, even when other influencing factors were taken into account. The ratio of the difference between the number of ridges on the thumb and 5th finger is one way of predicting the probability of an individual developing diabetes in later life:

Fingerprints may provide a useful tool to investigate prenatal developmental plasticity.

Epigenetics, or the influence of environment on gene expression, has become recognised as an influencing factor in type 2 diabetes [2]. Other body measurements predicting similar disease risk, such as the waist-to-thigh ratio, are also correlated with fingertip ridge counts [3]. Evidence for the significance of epigenetic influences during early prenatal life is compelling, and should be used as the basis for a preventive strategy starting before conception. Dermatoglyphics is used in The GenoType Diet, along with other markers of gene expression, not only to predict future disease risks, but to target specific prevention strategies.

--

References:

1. Kahn HS, Graff M, Stein AD, Lumey LH. "A fingerprint marker from early gestation associated with diabetes in middle age: the Dutch Hunger Winter Families Study." Int J Epidemiol. 2009 Feb;38(1):101-9.
PMID: 18684786

2. Ling C, Groop L. "Epigenetics: a molecular link between environmental factors and type 2 diabetes." Diabetes. 2009 Dec;58(12):2718-25.
PMID: 19940235

3. Kahn HS, Graff M, Stein AD, Zybert PA, McKeague IW, Lumey LH. "A fingerprint characteristic associated with the early prenatal environment." Am J Hum Biol. 2008 Jan-Feb;20(1):59-65.
PMID: 17929242

A new study to be published in Schizophrenia Research[1] has found that markings on the hand may be a sensitive marker for genetic and environmental factors in schizophrenia.

Anthropologists in Barcelona, Spain studied the hand patterns of patients with schizophrenia, their relatives and healthy 'control' subjects. They looked at A-B ridge count, which is the number of ridges between two points on the palm called A and B (defined by specific areas where patterns converge under the second and third digits). There was no overall difference in A-B ridge count, but A-B ridge count was lower (fewer ridges) in schizophrenic patients with a low birth weight, and also in patients who did not have a family history of schizophrenia.

According to the study, the frequency of ectodermic derivates abnormalities (that is, Ridge Dissociation [RD] and/or Abnormal Palmar Flexion Creases [APFC] - abnormalities originating from the embryonic ectodermal layer of tissue, including the epidermis) appeared to be higher in patients and relatives than in controls. Ridge dissociation refers to short broken segments of lines that cover the patterns of dermatoglyphic areas in a disorganized way. Examples of abnormal palmar flexion creases are the Simian line, the Sydney line, clear broken proximal and distal palmar creases, and very rudimentary creases. Associations of this kind studying RD and APFC have been found in previous studies, one of them[2] concluding that factors affecting early foetal development may increase the risk for psychotic disorder. In this new study males had more of these abnormalities than females, which also shows the potential influence of male hormones in response to stress. Males also had more fluctuating asymmetry of their A-B ridge count (difference between left and right hands).

Overall these studies show the importance of maintaining a peaceful and stress-free environment for the unborn child, as well as highlighting a potentially observable risk factor for schizophrenia.

References:
1: Fatjó-Vilas M, Gourion D, Campanera S, et. al.
"New evidences of gene and environment interactions affecting prenatal neurodevelopment in schizophrenia-spectrum disorders: A family dermatoglyphic study."
Schizophr Res. 2008 Jun 24.
PMID: 18583099

2: Rosa A, Fañanas L, Bracha HS, Torrey EF, van Os J.
Am J Psychiatry. 2000 Sep;157(9):1511-3.
Congenital dermatoglyphic malformations and psychosis: a twin study.
PMID: 10964873

Read more »