Our study is the first genetic association study on longitudinal height growth in a large prospective cohort study from birth to adulthood. Frequent height measurements (on average 20 measurements/person) with exact measurement times were obtained from health clinic records. The data are representative of the original cohort and thus the population of Northern Finland (see Representativeness in Materials and Methods). Frequent height measurements from birth to adulthood are rarely available in large population based studies and this makes replication of the results challenging. Fitting similar models and deriving similar phenotypes across study populations would be required to ensure comparability of the results. This is, however, impossible without dense measurement points. One possibility in the future is to combine several smaller studies with dense height growth measurements for replication and meta-analysis.
