AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 59243-249(19821 Dermatoglyphics of Hyperactive Males LESLIE Y. MORGAN, RICHARD C. JUBERG, DALAND R. JUBERG, A N D ROBERT P. HARDMAN Department of Medical Genetics and Birth Defects, Children’sMedical Center (L.EM.. R . C J , D.R.J.IandDepartment ofPediatrics (R.C.J,R.P.H.), Wright State University School o f Medicine, Dayton, Ohio 45404 K E Y WORDS Hyperactivity Behavior, Dermatoglyphics, Flexion creases, Genetics, ABSTRACT In investigating the dermatoglyphics of hyperactive subjects, it was proposed that if similar hyperactives were sampled and significant differences were found from suitable controls, a genetic effect could be responsible. From two clinical populations, we ascertained 26 subjects in 24 sibships comprising the hyperactive study group. The control subjects came from an earlier study. Tables 2-9 contain summaries of the dermatoglyphic analyses of both subjects and controls. Data were grouped following a dermatoglyphic principle of complexity of pattern, specifically, and the number of triradii present. The scheme for reporting the results is: selection of the characteristic (pattern, ridge count); determination of the areas (digit, palm, sole); and comparison of the frequencies or counts in the two populations (hyperactives, controls). Among the 45 statistical tests, four achieved a 5% level of significance. Thus, with a seemingly homogeneous sample of hyperactive males and with criteria for comparisons, no characteristic dermatoglyphic features emerged. Considering the highly characteristic effects of chromosomal abnormality on dermatoglyphics as well as the features associated with an early intrauterine developmental disturbance, the lack of dermatoglyphic similarities in these hyperactive males reduces the likelihood of such a profound factor as a causal mechanism. Hyperactivity in childhood has escaped causal understanding at least partly because of difficulty distinguishing between hyperactive and normal behavior. Hyperactivity commonly disturbs someone-a parent, a teacher, or any person in frequent communication with the accused- but tolerance of irritating behavior differs among persons. Other reasons exist for the lack of understanding: the frequent assumption that hyperactivity may be transient; the hope that amelioration may be achieved by behavior modification or medication; and the belief that the behavior will not interfere with progress to a normal adult life. Such reasoning suggests that hyperactivity deserves no effort in etiologic research. How. ever, hyperactivity frequently interferes with educating the affected and usually disturbs any others sharing the same environment. Views differ concerning the origin, manifestations, and even the existence of the hyperac- 0002-9483/82/5903-0243$02.500 1982 ALAN R. LISS, INC. tive syndrome. Some observers point to possible disturbances in the neurochemistry or neurophysiology of the central nervous system. One extreme of the etiological spectrum hypothesizes complete genetic determination, while the other extreme claims total environmental determination. Between these extremes, interactive contributions of genetic and environmental factors could be implicated, although not necessarily in the same proportions in all cases. A genetic component could result from a major gene effect. Such a gene produces a pronounced phenotypic effect. A major gene controls the production of a discontinuous or qualitative character in contrast to a minor gene, which, along with similar genes, has an individually small effect. These polygenes control Received January 4, 1982; accepted April 18, 1982. 244 L.Y. MORGAN, R.C. JUBERG, D.R. JUBERG, AND R.P. HARDMAN common polygenic effects. A major gene might be X linked and recessive considering the male predominance and occasional sibships with similarly affected brothers. The occurrence of an affected female is compatible with X linkage if her father were affected and her mother a carrier. Furthermore, the prevalence attributed to hyperactivity suggests a high gene frequency resulting in a high frequency of carrier females. This would explain apparent male-to-male transmission, the classic evidence against X linkage. A genetic component also could be ascribed to minor gene effects. These, as well as a major gene, could affect behavior in concert with environmental factors. Minor gene effects constitute the mechanism of polygenic inheritance. Several common congenital malformations are ascribed to multifactorial determination, of which the genetic component comes from the polygenic effect of minor genes, and aberrant sex ratios in them can be explained by differential male or female susceptibility. Indeed, in a study of adopted hyperactive children, the data were consistent with genetic determination, and a polygenic model was postulated (Morrison and Stewart, 1973). Dermatoglyphic characteristics are mainly heritable. However, the precise mechanisms are not understood, and early in utero infections, such as rubella, can affect the developmental patterns. Though many of the quantitative aspects of dermatoglyphic characters appear to be determined polygenically, evidence supports single gene determination of certain specific combinations of patterns or sequences (Juberg et al., 1980; Morgan et al., 1978). Hyperactivity may be clinically heterogeneous. Likewise, it may be etiologically heterogeneous. Quite possibly many causes might produce this outward sign of underlying dysfunction. One twin study, however, offered evidence of a considerable heritable component to activity level (Willerman, 1973). Unfortunately, no clear objective identification of the hyperactive subject exists. Consequently, an investigation regarding genetic etiology, which may as well be heterogeneous, must strive to select a homogeneous clinical sample. In investigating their dermatoglyphics, we proposed that if we sampled similar hyperactives and found significant differences from suitable controls, a genetic effect could be responsible. This would imply an association, possibly developmental or genetic linkage, be- tween common factors determining the dermatoglyphics and hyperactivity. MATERIALS From two clinical populations, we selected 26 subjects in 24 sibships to comprise the hyperactive study group. All subjects were referred from sources familiar with evaluating hyperactive behavior: 1)the 4 sibships with 5 white subjects came from a specialty clinic at a nearby military hospital; and 2) the 20 sibships with 21 white subjects came from the private pediatric neurologic practice of one of the coauthors (R.P.H.), a practice recognized to be particularly experienced in diagnosing and assessing the causes of hyperactive behavior. All referrals during a restricted period of time were accepted, and although two females were referred, they were not included because of male-female differences in dermatoglyphics. The two referring physicians, familiar with each other and their clinical practices, collaborated in selecting the patients to form a homogeneous sample. In the opinion of the referring clinicians, one of whom in 20 years has evaluated over 20,000 referrals for hyperactivity, the subjects represented the extreme end of the spectrum of hyperactive syndrome most suggestive of underlying organic origin. Their selection followed an extensive family history, assessment of school reports and the results of psychoeducational testing, observation of familial interactions, and intensive physical examination, including detailed neurologic evaluation. Conventional procedure calls for the physician to obtain descriptions of behavior in order to diagnose the hyperactive syndrome (Forman, Hetznecker, and Dunn, 1979). The same authors stress that classroom observations and psychoeducational tests are most useful diagnostically. The study group presented a contrast to subjects at the opposite end of the spectrum, those with highly suspicious psychological origins. The subjects frequently demonstrated purposeless movements and were often restless. Parents and teachers alike noted their short attention spans, distractibility, and impulsiveness. They were described as easily frustrated and rather excitable. All had experienced emotional and behavioral difficulties. Three families contained two males similarly affected by hyperactive behavior: 1) two brothers; 2) dizygotic twin brothers; and 3) father and son. The mean age of the subjects was 12 DERMATOGLYPHICS OF HYPERACTIVE MALES TABLE 1. Birth order of 26' hyperactive subjects Sibship size ~~. 1 1 2 3 3 8 2 0 1 4 5 Birth order ~- 2 3 4 5 - - 0 - - 1 1 1 - 0 0 8 1 0 0 years. Excluding the probands, the sex ratio in their siblings was 1.0. Table 1 shows their birth order. At birth of the probands, mean maternal age was 25% years and mean paternal age was 28?h years. None of the parents was known to be consanguineous. All families resided in southwestern Ohio and were representative of the clinical population and private practice from which they were drawn. The control subjects came from an earlier study of laterality (Morgan et al., 1976). They were the 25 male, white probands in 54 families randomly ascertained in the summer session of Louisiana State University at Eunice in 1974. Two groups of students were enrolled at the time of that study: one consisted of the undergraduates attending the summer session, and the other comprised a group between their third and fourth high school years who were enrolled in a special program for students of high academic standing. Though not of concern at the time of the study, hyperactive behavior was not evident in any of the subjects, and we obtained no history of it. Through a later survey we were able to contact 19 families, and by specific inquiry we confirmed that none considered their sons to be hyperactive and neither had their teachers nor anyone else. All subjects were progressing normally or superiorly in school. We have previously shown their dermatoglyphic characteristics to be comparable with those of other populations (Morgan et al., 1978; Juberg et al., 1980). METHODS The dermatoglyphic prints of all subjects were obtained by inking the skin from either a prepared glass plate or a roller and then applying the inked surface to a glossy paper.' The prints were analyzed with a Wild M-8 Stereomicroscope following established guidelines W e obtained written intormed consent from 20 families and implied informed consent from 5 families in the hyperactive group and from all families of the control group 245 (Cummins and Midlo, 1961). The classification used was of Dar et al. (1977) for the flexion creases. One investigator (L.Y.M.) performed all analyses of prints from subjects and controls except for the classification of the flexion creases (D.R.J.). RESULTS Tables 2-9 contain summaries of the dermatoglyphic analyses of both subjects and controls. The qualitative data could not be analyzed by simple comparisons of pattern frequencies for all separate areas, because of the large numbers of classifiable variables and the small number of subjects. Thus, the grouped data followed a dermatoglyphic principle of complexity of pattern, specifically, the number of triradii present. Two triradii determine a whorl, whereas one triradius or none result in a loop or an arch, respectively. The scheme for reporting the results is: selection of the characteristic (pattern,ridge count); determination of the areas (digit, palm, sole): and comparison of the frequencies or counts in the two populations (hyperactives, controls). Statistical analyses employed x2,not requiring either correction for continuity (Yates)or testing for exact probability (Fisher), and Student's t. Pattern (whorl, nonwhorl) by digit x group (hyperactiue/control) There was no trend across the digits, and the presence or absence of a whorl did not differen tiate the two groups (Table 2). Analysis by x 2 for 10 digits with one degree of freedom (d.f.) showed a significant difference only for L, on which more whorls occurred in hyperactives (0.05 > p > 0.01). Pattern (whorl, nonwhorl) by hand x group lhyperactiue/control) The number of whorls on the left hand (0.05 > p > 0.01) as well as across both hands (0.05 > p > 0.01) did differentiate the two groups by more whorls present in the hyperactives (Table 2). Analysis was by x2 with 1 d.f. for the hands considered separately and together. Ridge counts b y individual digits and total digital ridge count x group lhyperactive/control) No difference existed between the two groups (Table3). Analysis for 10 digits individually and the total for all 10 digits was by Student's t with 49 d.f. 246 L.Y. MORGAN, R.C. JUBERG, D.R. JUBERG, AND R.P. HARDMAN TABLE 3. Individual and total digital ridge counts in 26 hyperactive and 25 control subjects Digit L, L 2 L3 L4 w a m o vcr mu, N N L5 R, R> R3 0 0 c) '6i 6 m m 0 0 0 0 0 0 0 - 0 0 d h NN - 3 mm m a m N 1 3 0 0 NQ, 0 0 0 0 ,-I R4 R5 Total Mean and standard deviation Subject Hyperactive Control 18.3 + 5.0 11.7 f 7 . 3 13.3k7.1 16.5 f6.3 14.4 + 4.8 20.1 k 6 .1 11.5 + 7 .2 13.8 f 7.4 17.3 +5.2 16.0 f 4.6 17.3 f 6.5 11.5 k 8 .3 13.0 k 6 . 8 16.6 f 6.4 14.3 + 5.7 21.4 f 5.5 13.0 8.1 13.4 f6.3 16.9 f 7.5 15.1 f 5.5 153.3 k 48.9 152.4 f 55.2 Palmar pattern (third interdigital, fourth interdigital, hypothenar) distribution by hand (unilateral and bilateral) x group (hyperactive/control) The distribution of a true palmar pattern on either side, the left or the right side, or on both sides, or on neither, thus making four classes, in the third interdigital, fourth interdigital, or hypothenar region did not differentiate the two groups (Table 4). The three areas considered were those in which patterns, usually loops but occasionally whorls, most commonly occur. Three remaining areas, second interdigital, first interdigital, and thenar, less commonly have patterns. Analysis was by x 2 with 3 d.f. Palmar pattern (third interdigital, fourth interdigital, hypothenar) occurrence by hand (unilateral by side or either side) x group (hyperactive/control) With one exception, no significant differences existed between the two groups where a true pattern occurred (Table 4).The exception was the left hypothenar area in which the occurrence in hyperactives exceeded that in controls (0.05 > p > 0.01). Analysis was done by xz with 1d.f. for unilateral left, unilateral right, or either side for the three areas taken separately. Size o f atd angle by hand x group (hyperactive/control) No significant differences emerged from comparison of size of the atd angles (Table 5). The atd angle is largely a function of the site of the axial triradius, t, but it is also determined 247 DERMATOGLYPHICS OF HYPERACTIVE MALES T A B m 4. Frequency of unilateral and bilateral true patterns in the third interdigital, fourth interdigital, and hypothenar patmar areas in 26 hyperactive and 25 control subjects Palmar area Side Unilateral left Unilateral right Bilateral Either unilateral or bilateral Subject Third interdigital Fourth interdigital Hyperactive Control Hyperactive Control Hyperactive Control Hyperactive Control 14 15 by the sites of the a and d triradii. Analysis of each side was by Student’s t with 49 d.f. A-B ridge count by hand x group (hyperactiue/control) Side Left Right Both Angle (degrees) Mean and standard deviation Hyperactive Control 48.6 f 13.1 47.4* 8.8 96.1 f 20.5 4 5 . 6 i 7.7 4 5 . 1 i 6.7 90.3 & 11.8 TABLE 6. A-B ridge count of each palm in 26 hyperactive and 25 control subjects Side Left Right Both Ridge count Mean and standard deviation Hyperactive Control * 44.4 4.9 43.7 i4.7 88.1 f8.0 43.4 f 4.6 43.5 6.0 86.9 +9.6 * 9 tance between these palmar triradii, situated at the bases of the second and third digits. Analysis was by Student’s t with 49 d.f. separately by hand and for the sum of both hands. Frequency of palmar main line sequence by side (unilateral and bilateral) x group (hyperactivekontrol) No significant differences came from comparing the ridge counts between the a and b triradii (Table 6). This is one measure of the disTABLE 5. A T D angle of each palm in 26 hyperactive and 25 control subjects Hypothenar Main line sequences are not susceptible to grouping, and the number of unique sequences prohibited the accumulation of large enough totals for testing (Table 7). The three most common sequences occurred in approximately equal numbers in the two groups. The main line sequence was determined by constructing a line from the midpoint of the third digit to the midpoint of the wrist and listing the lines in their order of crossing from distal to proximal. Appropriate designations for parallel lines, for lines emanating from accessory triradii, and for main lines that did not cross the constructed line were used. Hallucalpattern by type and side (unilateral or either) x group (hyperactive/control) Hallucal patterns as distal loop, tibial loop, whorl, or fibular arch were classified and their occurrence on individual side or on either foot TABLE 7. Frequency of palmar main line sequences in 26 hyperactive and 25 control subjects Frequency Main line sequence ___CBDAT CDBAT DCBAT 17 others summed Left Hyperactive Control 7 7 5 2 12 4 5 9 Right Hyperactive 10 8 3 5 Control 12 6 2 5 Both Hyperactive 11 13 5 17 Control 19 10 7 14 248 L.Y. MORGAN, R.C. JUBERG, D.R. JUBERG, AND R.P. HARDMAN TABLE 8. Frequency o f hallucal patterns on each foot in 26 hyperactive and 25 control subjects Frequency Hallucal pattern Left Hyperactive Loop, distal Loop, tibia1 Whorl Arch, fibular Control 12 14 5 7 2 2 9 0 TABLE 9. Frequency Right Hyperactive 14 3 8 1 Typical, type A, , Typical, type A2.t Typical, type Simian, type Bo., Simian, type B2.1 Simian, type B3.3 Unusual, type D, I Both Hyperactive 26 8 15 3 13 3 9 0 Control 27 5 18 0 of palmar flexion crease patterns in 26 hyperactive and 25 control subjects ____._________. Palmar flexion crease pattern Control Left Hyperactive 19 4 0 0 1 2 0 Control 11 2 4 0 0 1 1 were tested (Table8).There were no significant differences among the three x2 tables with 3 d.f. Other plantar areas were not studied. Palmar flexion crease type by hands together x group (hyperactiue/control) Table 9 shows the classification of palmar flexion creases as typical, simian, and unusual, and the subclassification. For purposes of testing by x2 with 1 d.f., all typical were gathered and compared with all simian plus unusual creases. There was no significant difference. DISCUSSION Among the preceding 45 statistical tests, four achieved a 5% level of significance. In that many comparisons, by chance alone between two and three would be expected to be significant at the 5% level. Thus, with a seemingly homogeneous sample of hyperactive males with our criteria for comparisons, no characteristic dermatoglyphic features emerged. Nevertheless, the four significant differences can be summarized as showing: 1) the hyperactives had a more complex pattern than the,controls; 2) the more complex pattern was the whorl; and 3) the left hand, specifically the third digit and the hypothenar area, showed more complex patterns and more patterns, respectively. Only two prior studies bear similarity to this investigation. Lerer (1977)reported more simian creases and Sydney lines by direct observa- Frequency Right Hyperactive 20 3 2 0 0 1 0 Control 15 2 6 1 0 0 1 Both Hyperactive 39 I 2 0 1 3 0 Control 32 4 10 1 0 1 2 tion in hyperactive boys and girls than in the controls. Though included in our study, the flexion creases are not considered as dermatoglyphics, as originally defined by Cummins and Midlo (1961).The findings by detailed classification of the flexion creases, nevertheless, did not support the contention of abnormal palmar flexion creases in hyperactive children. In another study, dermatoglyphic abnormalities were not found in dyslexic children (Cummings et al., 1978). However, aside from an assumed common origin in the central nervous system, dyslexia and hyperactivity are not alike. Recently, the frequencies of fingerprint patterns in children with early-onset autism, a severe behavioral and communicative disorder, were compared with populations of childhood schizophrenics, adult schizophrenics, and normals (Sank and Firschein, 1979).There were no differences between autistics and childhood schizophrenics, but there were differences between autistics and adult schizophrenics and the controls. However, these are all much more severe behavioral disturbances than the hyperactive syndrome, suggesting genetic and thus earlier etiological determination. Characteristic dermatoglyphics commonly occur among certain kinds of clinical abnormalities, especially among subjects with various malformations of the hands and feet (Schaumann and Alter, 1976). Dermatoglyph- DERMATOGLYPHICS OF HYPERACTIVE MALES ics may be diagnostically abnormal in aneuploidy, more often when an additional chromosome is an autosome than when it is a sex chromosome. They may also be deviant to a lesser extent in structural chromosomal abnormalities, for instance, the deletion syndromes. Dermatoglyphics have not often been found to characterize disorders due to single gene inheritance or congenital malformation syndromes of unknown etiology. Considering the highly characteristic effects of chromosomal abnormality on dermatoglyphics as well as the features associated with an intrauterine developmental disturbance, it was believed that the lack of dermatoglyphic similarities in hyperactive males observed in the present study reduces the likelihood of such a profound factor as a causal mechanism. However, finding no characteristic dermatoglyphics in hyperactive males does not negate the possibility that some subjects with hyperactivity may be genetically determined. The possibility of genetic determination offers highly useful clinical applicability, including management of the affected and genetic counseling. ACKNOWLEDGMENTS The authors wish to thank Charles C. Faust, Ph.D., Louisiana State University in Eunice, for providing information. 249 LITERATURE CITED Cummings, C, Flynn, D. and Preuss. M (1978) Dermatoglyphic traits and minor anomalies in “dyslexic” children. Am. J. Hum. Genet., 30:lOlA. Cummins. H. and Midlo. C 119611 Finger Prints. Palms and Soles: An Introduction to Dermatoglyphics. New York: Dover Publications. Dar. H. Schmidt, R. and Nitowsky, HM (1977) Palmar crease variants and their clinical significance: a study of newborns a t risk. Ped. Res. I1:103-108. Juberg. RC, Morgan, LY, and Faust, CC (19801 The inheritance of digital dermatoglyphic patterns in 54 American Caucasian families. Am. J . Phys. Anthropol. 52:7-12. Lerer. RJ (1977)Do hyperactive children tend to have abnormal palmar creases? Clin. Ped. I6:645-647. Morgan, LY. Juberg, RC. and Faust. CC (1976) Digital dermatoglyphics correlated with laterality. Excerpta Medica. V International Congress of Human Genetics, Mexico City, 1976. no. 542, p. 205. Morgan, LY. Juberg, RC. and Faust CC 11978) The inheritance of palmar and hallucal dermatoglyphic patterns in fifty-four American Caucasian families. Am. J. Phys. Anthropol. 49:44 1-447. Morrison, JR. and Stewart, MA 119731The psychiatric stat u s of the legal families of adopted hyperactive children. Arch. Gen. Psychiatry 2.9888-891. Sank, D. and Firschein. BDS (19781 Fingerprints and lateral preferences of early-onset autism. In W. Wertelecki and C.C. Plato (edsl: Dermatoglyphics - Fifty Years LaLer. New York: Alan R. Liss. Inc.. pp. 679-695. Schaumann. B. and Alter. M (1976) Dermatoglyphics in Medical Disorders. New York: Springer-Verlag. Willerman. L 119731 Activity level and hyperactivity in twins. Child Dev. 4 4 2 2 8 - 2 9 3 .