Figure 3. Proposed flow chart 0-17.99 years Proposed flow chart for the diagnostic work-up of tall children aged 0-17.99 years. The flow chart consists of two main pathways. Initially, height standard deviation score and distance to target height (Tanner) are calculated. In case of a height standard deviation score ≤2.0 or height standard deviation score -target height standard deviation score ≤2.0, the child is classified as not-tall or not-tall for target height. We suggest that a second referral at height 170 cm before the age of 12.5 years in girls and 185 cm before the age of 14 years in boys for adult height prediction should be considered if a positive family history of delayed puberty is present. In case of a height standard deviation score >2.0 or height standard deviation score-target height standard deviation score >2.0, each subsequent step is aimed at excluding pathologic causes requiring further investigation and possibly treatment. The final step is to determine whether the tall child is familial tall or non-familial tall.