HEIGHT
Birth length and postnatal growth during the first months of life is relatively normal in achondroplasia but thereafter growth velocity abruptly slows down causing a major decrease in height position …
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.
Background Material
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).
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 growth chart booklet covers both 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 booklets also include charts for weight and BMI as well as the body proportion measurements sitting height, leg length, arm span, and foot length.
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 growth chart booklet covers both 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 booklets also include charts for weight and BMI as well as the body proportion measurements sitting height, leg length, arm span, and foot length.
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 specific growth details
Birth length and postnatal growth during the first months of life is relatively normal in achondroplasia but thereafter growth velocity abruptly slows down causing a major decrease in height position …
The growth deficit in height cannot easily be translated or compared to weight due to the greatly distorted ratio between trunk and legs, which also changes with age, and possibly also due to increased head size …
Macrocephaly is typical for achondroplasia although at birth head circumference is usually only marginally increased (mean 36.7 cm). Head size increases rapidly during the first year of life and about 90% of adult head circumference is achieved by 2 years of age …
Sitting height in achondroplasia develops within lower normal range and deviation from the general population during prepubertal ages is remarkably constant, …
Merker, A., Neumeyer, L., Hertel, NT., Grigelioniene, G., Mäkitie, O., Mohnike, K., Hagenäs, L. Growth in achondroplasia: Development of height, weight, head circumference, and body mass index in a European cohort. Am J Med Genet – Part A. 2018 (176): 1723-1734. doi: 10.1002/ajmg.a.38853
Merker, A., Neumeyer, L., Hertel, NT., Grigelioniene, G., Mohnike, K., Hagenäs, L. Development of body proportions in achondroplasia: Sitting height, leg length, arm span, and foot length. Am J Med Genet – Part A. 2018 (176): 1819-1829. doi: 10.1002/ajmg.a.40356
Neumeyer L, Merker A, Hagenäs L. Clinical charts for surveillance of growth and body proportion development in achondroplasia and examples of their use. Am J Med Genet – Part A. 2020 (185): 401-412. doi: 10.1002/ajmg.a.61974
doi: 10.1002/ajmg.a.38853
doi: 10.1002/ajmg.a.40356
doi: 10.1002/ajmg.a.61974
The clinical growth charts were constructed in cooperation with PC PAL (www.pcpal.eu), a company specialized in growth monitoring software. PC PAL is making these achondroplasia growth charts available in their decision support suite GrowthXP so that the charts can be directly integrated into electronic health record (EHR) systems and used with existing data.
For more information visit: www.GrowthXP.com