Clinical surveillance of infants and children with achondroplasia necessitates syndrome-specific charts due to extreme short stature with deviating body proportions. Height, arm span and leg length develop far below normal population ranges despite sitting height being only mildly affected. Head circumference is on the contrary greatly increased with increased tempo in development that should be surveilled the first years of life.
The charts are based on semi-longitudinal standardized measurements of 210 boys and 256 girls from Scandinavia and Germany from about 4,400 measurement occasions.
The majority of measurements were conducted by the same observer mainly during routine visits at the skeletal dysplasia clinic at the Department of Pediatrics at Karolinska University Hospital in Stockholm, Sweden, and at annual meetings of the German Association for People of Short Stature and their Families (Bundesverband Kleinwüchsige Menschen und ihre Familien e.V., BKMF).
Achondroplasia growth charts
The growth charts covers infancy (0-4 years) and childhood-adolescence (4-20 years) at separate charts. Head circumference, height and weight during infancy is combined on one page using non-linear axes to account for higher growth velocity at younger ages.
In this way, similar importance/resolution is given to the varying developmental velocities. It makes it possible to follow individual growth patterns in detail also during infancy when height velocity is highest. The use of nonlinear axes for some measured variables (y-axes) adapts the curve area to the magnitude of the variable conferring sufficient visual and plotting sensitivity to allow for short time detection of abnormal growth pattern.
The chart collection also include charts for weight and BMI as well as the body proportion measurements sitting height, relative sitting height, leg length, arm span, and foot length.
Achondroplasia growth specific details: