Evaluation of relationship between digit ratio (2D: 4D) and epilepsy: Can 2D:4D be a clue for epileptogenesis?

Abstract

Objective: The aim of the study was to investigate the possible association between the 2D:4D

ratio and epilepsy in male and female adults, and to compare the ratios of epilepsy patients and

healthy control subjects.

Patients and Methods: A case-control study carried out at a neurology and biophyiscs

department in Ankara Yıldırım Beyazıt University, Faculty of Medicine from May 2016 to January

2017. The 2D:4D ratios of both the left and right hands of 172 epilepsy patients and 202

matched healthy controls were recorded. All participants also completed the Edinburgh

handedness inventory.

Results: A significant positive correlation between the 2D:4D ratio and epilepsy was found for

both females and males; a lower ratio for the left hand was associated with a higher possibility

of epilepsy. In addition, a lower ratio in a specific hand was associated with that hand being

used to complete the handedness test.

Conclusions: The 2D:4D ratio serves as a predictor for increased risk of epilepsy. Thus, it could

be used as a marker to differentiate patients with epilepsy from healthy controls.

Keywords

• Digit ratio,2D:4D,Edinburg handedness test,epilepsy,hand

References

1. 1. Engel J, Pedley TA, Aicardy, J, and Dichter MA. Epilepsy: A Comprehensive Textbook, 2nd Ed. Philadelphia; Lippincott, Williams & Wilkins 2007.
2. 2. Pearson-Smith JN, Patel M. Metabolic Dysfunction and Oxidative Stress in Epilepsy. Int J Mol Sci. 2017;8:18-21.
3. 3. Zaidi Z. Body asymmetries: Incidence, etiology and clinical implication. Australian J Basic Applied Sci 2011;5:2157–91.
4. 4. Good CD, Johnsrude I, Ashburner J, Henson RNA, Friston KJ, Frackowiak RSJ. Cerebral asymmetry and the effects of sex and handedness on brain structure: A voxel-based morphometric analysis of 465 normal adult human brains. NeuroImage. 2001;14.
5. 5. Fink B, Manning JT, Neave N. The 2nd–4th digit ratio (2D:4D) and neck circumference: Implications for risk factors in coronary heart disease, Int J Obesity. 2006;30:711–4.
6. 6. Stolten M, Ledet E, Dotiwala A, Luk E, Sartor O. Alternative digit ratios and their relationship to prostate cancer, Clin Genitourin Cancer. 2016;14:149–52.
7. 7. Kasielska-Trojan A, Antoszewski B. Can digit ratio (2D:4D) studies be helpful in explaining the aetiology of idiopathic gynecomastia? Early Human Development 2015;91:57–61.
8. 8. Manning JT, Baron-Cohen S, Wheelwright S, Sanders G. The 2nd to 4th digit ratio and autism. Develop Medicine & Child Neurol. 2001;43:160– 4.

9. 9. Manning JT. Digit Ratio: A Pointer to Fertility, Behavior, and Health. Rutgers Univ. Press, New Brunswick NJ 2002.
10. 10. Bejerot S, Erikson JM, Bonde S, Carlström K, Humble MB, Eriksson E. The extreme male brain revisited: Sex coherence in adults with autism spectrum disorder. Brit J Psychiatry. 2012;16;118–123.
11. 11. Robinson SJ, Manning JT. The ratio of 2nd to 4th digit length and male homosexuality. Evolution Human Behavior. 2000;21:333–45.
12. 12. Triversa R, Manningb J, Jacobsona A. A longitudinal study of digit ratio (2D:4D) and other finger ratios in Jamaican children. Hormones Behavior. 2006;49:150–6.
13. 13. Ertugrul B, Otag I. Relationship between sexually dimorphic body morphology and second-to-fourth digit ratio. Insan Bilim Derg.i 2012;1:94–107.
14. 14. Hudson JM, Hodgson JC. Is digit ratio (2D:4D) a reliable pointer to speech laterality? Behavioral Brain Res. 2016;301:258–61.
15. 15. David AP, Steven JCG, Robert JS, Donald HM. Sex hormones and finger length. What does 2D:4D indicate? Evolution Human Behavior. 2004;25:182–99.
16. 16. Lutchmaya S, Baron-Cohen S, Raggatt P, Knickmeyer R, Manning JT. 2nd to 4th digit ratios, fetal testosterone and estradiol. Early Hum Dev. 2004;77:23–8.
17. 17. Malas MA, Dogan S, Evcil EH, Desdicioglu K. Fetal development of the hand, digits and digit ratio (2D:4D), 2006, Early Human Development. 2006;82:469–75.
18. 18. Putz DA, Gaulin SJC, Sporter RJ, McBurney DH. Sex hormones and finger length What does 2D:4D indicate? Evolution Human Behavior. 2004;25:182-199.
19. 19. Manning JT, Scutt D, Wilson J, Lewis-Jones DI. The ratio of 2nd to 4th digit length: A predictor of sperm numbers and concentrations of testosterone, luteinizing hormone and oestrogen., Hum Reprod. 1998;13:3000–4.
20. 20. Geschwind N, Behan P. Left-handedness: Association with immune disease, migraine, and developmental learning disorder, National Acad Sci. 1982;79: 5097–5100.
21. 21. El-Khayat HA, Shatla HM, Ali GK, Abdulgani MO, Tomoum HY and Attya HA. Physical and hormonal profile of male sexual development in epilepsy. Epilepsia. 2003;44:447–52.
22. 22. Scharfman HE, Kim M, Hintz TM and MacLusky NJ. Seizures and reproductive function, insights from female rats with epilepsy. Ann Neurol. 2008;64:687–97.
23. 23. Bauer J, Stoffel-Wagner B, Flügel D, Kluge M, Schramm J, Bidlingmaier F, et al. Serum androgens return to normal after temporal lobe epilepsy surgery in men. Neurology 2000;55:820–4.
24. 24. Logothetis J, Harner R and Morrel F. Theroleofestrogens in catamenial exacerbation of epilepsy. Neurology. 1959;9:352–60.
25. 25. Reibel S, André V, Chassagnon S, André G, Marescaux C, Nehlig A, et al. Neuroprotective effects of chronic estradiol benzoate treatment on hippocampal cell loss induced by status epilepticus in the female rat. Neurosci Lett. 2000;281:79–82.
26. 26. Garn SM, Burdi AR, Babler WJ, Stinson S. Early prenatal attainment of adult metacarpal-phalangeal rankings and proportions, Am J Phys Anthropol. 1975;43:327–32.
27. 27. Fink B, Manning JT and Neave N. The 2nd–4th digit ratio (2D:4D) and neck circumference: Implications for risk factors in coronary heart disease. Int J Obesity. 2006;30:711–714.