Screening of turner syndrome with novel auxological criteria facilitates early diagnosis.

Abstract

Screening criteria for abnormal growth in children are traditionally based on height-for-age, height distance from target height (TH), and change in growth rate. However, there is no consensus on the optimal screening limits. Our objective was to first develop new population-based and age-specific cutoffs for these three screening parameters and, second, to validate their performance in screening by using Turner syndrome (TS) as a model. Reference values for the height distance from TH and growth rate were defined in a total of 14,189 healthy girls aged 0-18 yr with 147,469 height measurements. The best formula for TH calculation was TH sd score = 0.79 × mid-parental height sd score - 0.15. We also calculated age-specific limits for the distance from TH and limits for growth rate that were freely scalable between age range 0-12 yr. Longitudinal growth data of a cohort including 124 TS girls were evaluated with receiver operating characteristic analysis against the reference population. The screening accuracy for TS was excellent when we combined all three screening parameters. Sensitivity was 97% and specificity 96% for all TS girls and 100% and 95% for 45,XO TS girls, respectively. The detection rate was 68% for all and 76% for 45,XO TS girls with 99% specificity by the age of 2 yr. These new population-based screening rules for TS are sensitive and specific, but their use is complex, and therefore their efficient use requires computerization.