How valid are the rates of Down syndrome internationally?

Rates of Down syndrome (DS) show considerable international variation, but a systematic assessment of this variation is lacking.

Authors:
Leoncini E, Botto LD, Cocchi G, Anneren G, Bower C, Halliday J, Amar E, Bakker MK, Bianca S, Canessa Tapia MA, Castilla EE, Csaky-Szunyogh M, Dastgiri S, Feldkamp ML, Gatt M, Hirahara F, Landau D, Lowry RB, Marengo L, McDonnell R, Mathew TM, Morgan M, Mutchinick OM, Pierini A, Poetzsch S, Ritvanen A, Scarano G, Siffel C, Sipek A, Szabova E, Tagliabue G, Vollset SE, Wertelecki W, Zhuchenko L, Mastroiacovo P

Authors notes:
American Journal of Medical Genetics Part A 2010;152A:1670-80

Keywords:
rates of Down syndrome, internationally, International Clearinghouse for Birth Defects Surveillance and Research

Abstract:
Rates of Down syndrome (DS) show considerable international variation, but a systematic assessment of this variation is lacking. The goal of this study was to develop and test a method to assess the validity of DS rates in surveillance programs, as an indicator of quality of ascertainment.