Digital Dermatoglyphic Patterns Of Annang Ethnic Group In Akwa Ibom State Of Nigeria

摘要

Digital dermatoglyphics has been found useful in forensic medicine and identification purposes. It is useful in medical diagnosis of genetically inherited diseases and in detection of crimes. Anthropometric studies of the digit, palm and feet provides data that reveal the relative distribution of dermal ridges among people in different geographical zones. Cross-sectional study was carried out using 200 males and 200 females healthy volunteers of Annang ethnic group in Akwa Ibom State of Nigeria to establish their digital dermatoglyphic traits. This was done by counting and classifying their ridge pattern configurations of arches, loops and whorls. Ulnar loops were the most predominant digital pattern in females (50.1 percent) than in males (39.6 percent), followed by whorls (42.9 percent) in males, then arches (31.1 percent) in females and radial loop (2.1 percent) in males. The sex differences between these patterns were statistically significant (chi2 equal to 154.569; d.f. equal to 4; 0.001 greater than P). The index of pattern intensity (P11) showed a higher value in males (15.13) than the females (11.88). Sexual dimorphism was also evident with the males showing higher total finger ridge count (TFRC) than the females (p < 0.001). This study has established for the first time the normal dermatoglyphic patterns of Annang ethnic group in Akwa Ibom State of Nigeria. Introduction Through decades of scientific research, the hand has come to be recognized as a powerful tool in the diagnosis of psychological, medical and genetic conditions. It was in 1926 that Cummins introduced the term “Dermatoglyphics”. It is the term applied to the study of the naturally occurring patterns of the surface of the hands and feet 1. Finger ridges and ridge patterns are highly heritable, durable, and age-independent human traits and have been studied as a model quantitative trait in humans for over 80 years 2. They develop between approximately the 13th and 18th weeks of gestation, and in the absence of trauma remain essentially unchanged throughout life. The cutaneous mechanoreceptive afferent neurons that innervate the fingertips develop in alignment with the ridges, lending support to the theory that fingerprints play a role in gripping, and tactile perception 345. The development of ridge patterns coincides with the regression of embryonic volar pads on fingers, and the type and size of patterns are largely determined by the size and timing of subsidence of these pads 6. Genetically or environmentally determined growth disturbances that affect the limbs in the critical period of ridge formation may also affect normal development of ridges and ridge patterns. Traditionally, the ridge count is defined as the number of ridges that intersect or touch the line drawn from the easily recognized triradius (where three ridges meet) to the center of the pattern 7. The most common pattern, a simple loop (60%–70% of all patterns, characterized by a single triradius, is most advantageous for tactile perception and precision grip 378. Whorls have two triradii yielding two counts, while simple arches have no true triradii, resulting in a zero count. The study of palmar, and finger prints has a primary aim of identifying individuals sex, race, ethnic differences as well as serving as a tool in the diagnosis of congenital malformations 7, 910.The existence of ethnic and racial differences has however necessited the documentation of parameter values for use in each ethnic group, race or region of the world. Such parameters values do not exist for Annang ethnic group in Akwa Ibom State of Nigeria. Thus this study was aimed at determining and establishing the dermatoglyphic pattern among the Annang ethnic group. Materials And Methods A total of 400 indigenous Annang subjects of Akwa Ibom State origin distributed in Abak, Essien Udim, Etim Ekpo, Ika, Ikot Ekpene, Obot Akara, Oruk Anam and Ukanafun Local Government Areas, volunteered for the study. The study popula