Introduction 3 5 7 1 1 2 4 5 7 1 Fig. 1 A 7-year-old boy with Wolf-Hirschhorn syndrome  Materials and methods The study is based on data from 1,057 examinations of 101 children with WHS, 35 males and 66 females, born between 1975 and 2002. Data from 32 children were collected from records of individuals with WHS in the Netherlands. Another set of data was obtained from 69 children with WHS from Great Britain, North America, Germany and Australia who were contacted through WHS support groups. There were no exclusion criteria except growth hormone treatment. Thus, all children regardless of complicating disease such as heart defects, renal disease or feeding problems, were included. The number of observations in the Dutch group of children was higher than in the group of children from other countries. No difference in parameters related to growth was observed between Dutch and non-Dutch patients. The data used for creation of the growth charts were age at examination, height (cm), weight (kg) and head circumference (cm). The growth charts cover the time period from birth until 4 years of age. 6 Data for weight and height were transformed into logarithms before statiscal analysis in order to obtain normal distributions. All growth charts are based on means and standard deviations. The software used was SPSS version 10 and Sigmaplot version 8.02 bij SPSS Inc. Results 2 3 Fig. 2 Growth chart for height for girls  Fig. 3 Growth chart for height for boys  4 5 6 Fig. 4 Growth chart for weight for girls  Fig. 5 Growth chart for weight for boys  Fig. 6 Growth chart for head circumference for boys and girls  Discussion 1 1