Searching for XYY males through electrocardiograms.

Price (1968) found that 300o of 20 males with 47,XYY karyotype had electrocardiograms (ECG) with prolonged P-R intervals. This prompted us to try to ascertain double-Y males by screening a large sample of clinically normal males through their ECG. From a file of about 30,000 ECGs, collected by one of us (M.F.L.) during the last 7 years, 34 were selected because (1) they were normal except for having P-R intervals of 0 2 second or more and (2) they belonged to clinically and radiologically normal adult males of less than 50 years of age, who were not taking any drugs. The karyotypes of 11 of these subjects were studied. One of them (F.N., Fig. 1) had a P-R interval of 0-24 second and a 47,XYY chromosome complement (in each of the 34 cells studied). This subject is a tall (192 cm), middle-class married businessman with no criminal record. He has a son and a daughter who are apparently normal. Each of the other 10 subjects in this series showed a 46,XY karyotype. However, 2 of them, with P-R intervals of 0-22 sec (R.S.) and 0-20 sec (M.B.) had an abnormally long Y chromosome (Figs. 2a and 2b).