Maternal and Child Health Bureau ~ 13
6. Issues regarding the use of condition-specific growth charts
In the case of chromosomal or genetic disorders, there may be a clear rationale for the development of reference growth data based on altered growth potential. However, other conditions exist which are also associated with altered growth patterns but where there is not a clear rationale for the development of such reference data. The most important reason for this is that there is no identifiable alteration in the genetic potential for growth in these conditions; rather, there is some other factor, either biological or environmental, which may influence the child's ability to achieve that potential.
Growth charts have been developed for a number of conditions for which growth patterns are altered. These include:
Trisomy 21 (Down syndrome) (Cronk, 1988)
Prader-Willi syndrome (Holm, 1995)
Williams syndrome (Morris, 1988)
Cornelia deLange syndrome (Kline, 1993)
Turner syndrome (Ranke, 1983; Lyon, 1985)
Rubinstein-Taybi syndrome (Reference)
Marfan syndrome (Pyeritz, 1983; Pyertiz, 1985)
Achondroplasia (Horton, 1978)
The current CDC recommendation is to use the CDC growth charts in all cases. However, recognizing the limitations of these special charts, which are discussed below, some clinicians may elect to use them, for example to illustrate to families how a specific condition can alter a child's growth potential.
Use of the special charts developed to assess growth of children who have conditions with no genetic or chromosomal basis for an altered growth pattern, such as cerebral palsy, is not recommended.
Limitations of specialized growth charts
The usefulness of specialized growth charts is limited by a number of factors:
Developed from very small samples
Data do not reflect racial, ethnic, or geographical diversity
Old data used to construct the charts
Difficult to be sure that the data are representative of the population as a whole or come from a well-nourished group of children within that population
Inconsistent measuring techniques used (in some cases, chart reviews were used to collect data; for other cases, the measurement techniques were not clearly defined)
Secondary medical conditions which influence growth potential (and which often accompany a primary chromosomal disorder) not considered