This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by van Trotsenburg, A. S. P. Articles by de Vijlder, J. J. M. Search for Related Content PubMed PubMed Citation Articles by van Trotsenburg, A. S. P. Articles by de Vijlder, J. J. M.

Lower Neonatal Screening Thyroxine Concentrations in Down Syndrome Newborns

Department of Pediatric Endocrinology, Emma Children’s Hospital AMC, 1105 AZ Amsterdam, The Netherlands

Address all correspondence and requests for reprints to: A. S. Paul van Trotsenburg, M.D., Department of Pediatric Endocrinology, Emma Children’s Hospital AMC, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands. E-mail: a.s.vantrotsenburg{at}amc.uva.nl.

There is an unexplained higher incidence of congenital hypothyroidism (CH) detected by T₄-based neonatal screening programs and a very high prevalence of (mild) plasma TSH elevation in young children with Down syndrome (DS). To determine whether newborns with DS have decreased blood T₄ concentrations at the time of the neonatal screening, we conducted an observational study in a large and representative cohort of Dutch children with DS born in 1996 and 1997. CH screening results (T₄, TSH, and T₄-binding globulin concentrations) were analyzed in comparison with clinical information obtained by interviewing the parents and data from the general newborn population and a large control group. The mean T₄ concentration of the studied children with DS (n = 284) was significantly decreased. The individual T₄ concentrations were normally (Gaussian) distributed but shifted to lower concentrations. This could not be explained by prematurity, nonthyroidal illness, or iodine exposure. Mean TSH and T₄-binding globulin concentrations were significantly increased and normal, respectively. The decreased T₄ concentration, left-shifted normal distribution, and mildly elevated TSH concentrations point to a mild hypothyroid state in newborns with DS and support the existence of a DS-specific thyroid (regulation) disorder. The question remains whether this contributes to the brain maldevelopment.

This work was partly supported by a grant from the Stichting tot Steun Emma Kinderziekenhuis AMC.

Abbreviations: CH, Congenital hypothyroidism; DS, Down syndrome; FT₄, free T₄; NTI, nonthyroidal illness; TBG, T₄-binding globulin.

This article has been cited by other articles:

				M. J. E. Kempers, C. I. Lanting, A. F. J. van Heijst, A. S. P. van Trotsenburg, B. M. Wiedijk, J. J. M. de Vijlder, and T. Vulsma Neonatal Screening for Congenital Hypothyroidism Based on Thyroxine, Thyrotropin, and Thyroxine-Binding Globulin Measurement: Potentials and Pitfalls J. Clin. Endocrinol. Metab., September 1, 2006; 91(9): 3370 - 3376. [Abstract] [Full Text] [PDF]

				A. S. P. van Trotsenburg, B. J. Smit, J. H. T. M. Koelman, M. Dekker-van der Sloot, J. C. D. Ridder, J. G. P. Tijssen, J. J. M. de Vijlder, and T. Vulsma Median Nerve Conduction Velocity and Central Conduction Time Measured With Somatosensory Evoked Potentials in Thyroxine-Treated Infants With Down Syndrome Pediatrics, September 1, 2006; 118(3): e825 - e832. [Abstract] [Full Text] [PDF]

				A. S. P. van Trotsenburg, T. Vulsma, S. L. R. van Rozenburg-Marres, A. L. van Baar, J. C. D. Ridder, H. S. A. Heymans, J. G. P. Tijssen, and J. J. M. de Vijlder The Effect of Thyroxine Treatment Started in the Neonatal Period on Development and Growth of Two-Year-Old Down Syndrome Children: A Randomized Clinical Trial J. Clin. Endocrinol. Metab., June 1, 2005; 90(6): 3304 - 3311. [Abstract] [Full Text] [PDF]

				G Van Vliet How often should we screen children with Down's syndrome for hypothyroidism? Arch. Dis. Child., June 1, 2005; 90(6): 557 - 558. [Full Text] [PDF]

				P A Gibson, R W Newton, K Selby, D A Price, K Leyland, and G M Addison Longitudinal study of thyroid function in Down's syndrome in the first two decades Arch. Dis. Child., June 1, 2005; 90(6): 574 - 578. [Abstract] [Full Text] [PDF]