Figure 4

Receiver operator characteristic curves for detection of 47,XXY (KS) and 48,XXXY (A) and 47,XYY syndromes (B). The average of the three XYM marker data points for each sample was calculated and compared to the detection thresholds. The threshold for detecting XXY and XXXY syndromes was varied by 1% increments from 34-48% Y allele signal; that for detecting XYY syndrome was incremented by 1% from 49-63%. The sensitivity (TP/(TP + FN)) and false positive rate (FP/(FP + TN)) were calculated for each value of the appropriate threshold. For XXY and XXXY, true positives (TP) have either a 47,XXY or 48,XXXY karyotype and average Y allele signal less than the threshold; false negatives (FN) have the same karyotypes and average Y allele signal greater than or equal to the threshold. True negatives (TN) for XXY and XXXY are samples with a 46,XY karyotype and average Y allele signal greater than or equal to the threshold; false positives (FP) have a 46,XY karyotype and average Y allele signal below the threshold. For XYY syndrome, true positives have 47,XYY karyotype and average Y allele signal greater than the threshold; false negatives have the same karyotype and average Y allele signal less than or equal to the threshold. True negatives for XYY are samples with a 46,XY karyotype and average Y allele signal less than or equal to the threshold; false positives have a 46,XY karyotype and average Y allele signal above the threshold.