Thomas W. Prior, PhD, Narasimhan Nagan, PhD, Elaine A. Sugarman, MS, CGC, Sat Dev Batish, PhD, and Corey Braastad, PhD

Genet Med (2011) DOI: 10.1097/GIM.0b013e318220d523

The ACMG Laboratory Quality Assurance Committee reaffirmed this guideline on March 9, 2016 with the following update to the Carrier Testing section on page 689: Recently, the presence of an extended haplotype block specific to SMN1 duplications was reported in individuals of Ashkenazi Jewish and African American ethnicities1. Testing for haplotype specific markers in conjunction with carrier testing offers an incremental improvement in residual risk estimates following a negative carrier test result.

1Luo M, Liu L, Peter I, Zhu J, Scott SA, Zhao G, Eversley C, Kornreich R, Desnick RJ, and Edelmann L. An Ashkenazi Jewish SMN1 haplotype specific to duplication alleles improves pan-ethnic carrier screening for spinal muscular atrophy. Genet Med 2014;16:149-56.

This Addendum was approved by the Board of Directors of the American College of Medical Genetics and Genomics on April 25, 2016.