Urinary osteocalcin is a useful marker for monitoring the effect of alendronate therapy.

References 1. Waters JJ, Waters KS. Trends in cytogenetic prenatal diagnosis in the UK: results from UKNEQAS external audit, 1987–1998. Prenat Diagn 1999;19: 1023–6. 2. Tepperberg J, Pettenati MJ, Rao PN, Lese CM, Rita D, Wyandt H, et al. Prenatal diagnosis using interphase fluorescence in situ hybridization (FISH): 2-year multi-center retrospective study and review of the literature. Prenat Diagn 2001;21:293–301. 3. Zimmermann B, Holzgreve W, Wenzel F, Hahn S. Novel real-time quantitative PCR test for trisomy 21. Clin Chem 2002;48:362–3. 4. Hu Y, Zheng M, Xu Z, Wang X, Cui H. Quantitative real-time PCR technique for rapid prenatal diagnosis of Down syndrome. Prenat Diagn 2004;24:704–7. 5. Slater HR, Bruno DL, Ren H, Pertile M, Schouten JP, Choo KH. Rapid, high throughput prenatal detection of aneuploidy using a novel quantitative method (MLPA). J Med Genet 2003;40:907–12. 6. Deutsch S, Choudhury U, Merla G, Howald C, Sylvan A, Antonarakis SE. Detection of aneuploidies by paralogous sequence quantification. J Med Genet 2004;41:908–15. 7. Pont-Kingdon G, Lyon E. Rapid detection of aneuploidy (trisomy 21) by allele quantification combined with melting curves analysis of single-nucleotide polymorphism loci. Clin Chem 2003;49:1087–94. 8. Antonarakis SE, Lyle R, Dermitzakis ET, Reymond A, Deutsch S. Chromosome 21 and down syndrome: from genomics to pathophysiology. Nat Rev Genet 2004;5:725–38. 9. Storm N, Darnhofer-Patel B, van den Boom D, Rodi CP. MALDI-TOF mass spectrometry-based SNP genotyping. Methods Mol Biol 2003;212:241–62. 10. Park C, Correll D, Oeth P. Measuring allele-specific expression using MassARRAY. Application Note. San Diego, CA: Sequenom, 2004. 11. Ross P, Hall L, Smirnov I, Haff L. High level multiplex genotyping by MALDI-TOF mass spectrometry. Nat Biotechnol 1998;16:1347–51.