Dermatoglyphic patterns in trisomy 8 syndrome.

Up to the present, 38 cases of trisomy 8 have been found. As most of the patients showed mosaicism, the clinical picture is variable and it seems possible that some mosaics will not be detected by the usual cytogenetic examination of blood cultures. We therefore examined the dermatoglyphics of our own case and compared the results with the findings in the other cases reported in the literature, in order to establish a typical dermatoglyphic pattern in trisomy 8 which might be useful in diagnosis. All patients exhibited several unusual dermatoglyphics, including: a low TFRC (x=96.06), high palmar (92.9%) and plantar (100%) pattern intensity, a distally placed axial triradius (62.5%), loop with accessory triradius in an interdigital area (91.7%), thenar (68.2%) and hypothenar (50.0%) patterns, simian crease (47.1%), bilateral arches on the great toes (88.9%) and hallucal-whorl (72.2%). A distinctive feature was the presence of zygodactylous triradii z, z' and z'' (100%) on the soles of the feet, and deep skin furrows on the palms and soles (68.2%). This combination of dermatoglyphic features appears to be characteristic for the trisomy 8 syndrome.