Utility of phenotypic dermal indices in the detection of Down syndrome patients.

Down syndrome (DS) is the most common cause of mental retardation. The frequency of DS patients is about 1:800 and is mainly because of the presence of extra copy of chromosome number 21. Dermatoglyphic has been well established as a diagnostic aid in number of diseases having hereditary basis. Dermatoglyphic data was obtained by the use of ink and prints on a paper, from 15 cytogenetically confirmed patients of Down syndrome attending to the genetic clinic at BPKIHS. The data were correlated and compared with equal number of controls. Dermatoglyphic prints were used to evaluate the variation in the fingerprint patterns, the presence of simian crease and the difference in 'atd' 'dat' and 'adt' angles between the control and the DS patients. The results showed that both the 'atd' and 'adt' angles differed significantly from the control group. The dactylography study revealed higher incidence of loops and lower incidence of whorls in the DS patients as compared with the controls. This method is non-invasive and cost effective. The observed changes in the 'atd' and 'adt' angles plus the fingerprint patterns in the dermatoglyphic study proved that this simple technique could be a valuable tool for selecting patients of DS for cytogenetics analysis.