Statement for Parents on Growth Hormone Treatment for Children with Down Syndrome

Annerén, Göran, M.D., Ph.D., Uppsala, Sweden
Bull, Marilyn J., M.D., Indianapolis, Indiana
Flórez, Jesús, M.D., Ph.D., Santander, Spain
Guyda, Harvey, J., M.D., Montreal, Canada
Mortimer, Joanne, M.D., Cleveland, Ohio
Pueschel, Siegfried M., M.D., Ph.D., Providence, Rhode Island 		  Reprinted from Down Syndrome Quarterly, Volume 1, Number 1, March, 1996
Dr. Samuel J. Thios, Editor
Denison University
Granville, OH 43023

Parents of children with Down syndrome are asking with increasing frequency about the possibility of growth hormone treatment. This question arises firstly from a report that suggests that children, some with Down syndrome, may have an abnormality in growth hormone secretion 1. The report may also lead to the assumption that children with Down syndrome who are treated with growth hormone will benefit from possible increase in adult height or by improvement in mental or motor function.

Concerning the first issue, there is no good evidence to support the idea that growth hormone deficiency is part of Down syndrome. Although they may show the same variability in growth hormone responses seen in normal children, most children with Down syndrome have normal serum growth hormone levels 2. Thus, consideration of the use of growth hormone in children with Down syndrome cannot be based only upon an expected abnormality of growth hormone secretion. As with all children, those with Down syndrome require close monitoring of growth, and it is important to recognize that they should be monitored using Down syndrome specific growth charts 3. Children whose growth rate deviates from the height growth chart should be referred for evaluation by a pediatric endocrinologist. When children have a proven growth hormone deficiency, a discussion of the risks and benefits of growth hormone treatment should be provided.

The second issue is more difficult since there are few studies that completely address the issue of benefit of treatment with growth hormone in children with Down syndrome. One study of 13 children with Down syndrome has demonstrated increased linear growth and an increase in head circumference following treatment with growth hormone for only one year.4 A long-term followup study on growth hormone treatment also reveals a significant increase in growth.5 A study of 16 children with Down syndrome treated from age 6-9 months for a period of three years revealed growth rate during the treatment period equal to that of children who do not have Down syndrome.6 In this study, there was no significant increase in head circumference. In addition, these same authors recently reported that their preliminary results do not reveal any improvement in motor or mental development in children with Down syndrome who have received growth hormone treatment.7 Neither study has determined the affect on final height on treated patients, nor have the studies discussed possible side effects of growth hormone treatment.

The administration of growth hormone to children with Down syndrome is not standard practice and its use remains investigational. In view of the complex issues involved, it is strongly recommended that parents wishing to consider growth hormone treatment should enroll their child in a proper scientific study.8 Such studies can control for variability in children with Down syndrome, and can include an assessment of behavior and learning in their outcome.

On the basis of the available evidence, and until the recommended scientific studies are completed, the uncontrolled use of hormonal treatments such as growth hormone in children with Down syndrome is not supported by the Down Syndrome Medical Interest Group.

References

  1. Castells, S., Torrado, C., Bastian, W., Wisniewski, K. E. (1992). Growth hormone deficiency in Down syndrome children. Journal of Intellectual Disabilities Research, 36(1), 29-43.
  2. Pueschel, S.M. (1993). Growth hormone response after administration of L-DOPA, clonidine, and growth hormone releasing hormone in children with Down syndrome. Research in Developmental Disabilities, 14(4), 291-298.
  3. Cronk, C.E., Crocker, A.C., Pueschel, S.M., Shea, A.M., Zackair, E., Pickens, G., Reed, R.B. (1988). Growth charts for children with Down syndrome: 1 month to 18 years of age. Pediatrics, 81, 102-110.
  4. Torrado, C., Bastian, W., Wisniewski, K.F., Castells, S. (1991). Treatment of children with Down syndrome and growth retardation with recombinant human growth hormone. Journal of. Pediatrics, 119(3), 478-83.
  5. Castells, S., Beaulieu, I. Wisniewski, K.E. (1993). Long-term effects of recombinant human growth hormone (rhGH) on children with Down's syndrome with short stature. In S. Castells & K. E. Wisniewski (Eds.), Growth hormone treatment in Down syndrome (pp. 163-182). New York, John Wiley & Sons.
  6. Annerén G., Gustafsson, J., Sara, V.R., Tuvemo, T. (1993). Normalized growth velocity in children with Down's syndrome during growth hormone therapy. Journal of Intellectual. Disabilities. Research, 37(4), 381-387.
  7. Annerén G. (1994). International Down Syndrome Research Conference. April 10-13, 1994. Charleston, SC.
  8. Allen, B., Frasier, S., Foley, T., Pescovitz, O. (1992) Growth hormone for children with Down syndrome. Journal of Pediatrics, 123, 742-743.
Source:
http://www.denison.edu/collaborations/dsq/growthhormone.html Revised: May 12, 2000.