2. Growth patterns of children with special
health care needs
that alter growth
which involve abnormalities at the chromosomal level, are associated with
growth patterns that differ from those of children without chromosomal
abnormalities. It is assumed that these differing growth patterns represent
altered growth potential related to the underlying chromosomal abnormality.
Examples of conditions related to chromosomal aberrations include Prader-Willi syndrome, Cornelia deLange syndrome, Turner syndrome, and trisomy 21 (also called Down syndrome).
21 will be used to illustrate the challenges in assessing the growth
of a child with any chromosomal disorder:
Children with trisomy
21 have an extra chromosome 21 in their cells. They also typically have
shorter stature, smaller head circumference and a different pattern
of growth, particularly during the first five years of life, than other
children (Feucht and Lucas, 2000). Because
of these differences, the growth of children with trisomy 21 is not
the same as that of the reference children used to develop the CDC growth
Recognition of the
differing growth pattern in the child with trisomy 21, and the problem
posed by comparing that child's growth to that of average children,
led investigators to develop and publish alternative growth charts used
with this population (Cronk, et al, 1988).
These charts have been used by nutritionists and other clinicians. However,
it must be emphasized that there are reasons for which these charts
should not be used or not used by themselves. The use of "condition-specific
growth charts" is covered in Section 6.
with genetic disorders, such as a metabolic disorder, there is the potential
for altered growth because the affected metabolic pathways are involved
in producing energy or building body tissue.