An empirical estimate of carrier frequencies for 400+ causal Mendelian variants: results from an ethnically diverse clinical sample of 23,453 individuals

Journal name:
Genetics in Medicine
Published online



Recent developments in genomics have led to expanded carrier screening panels capable of assessing hundreds of causal mutations for genetic disease. This new technology enables simultaneous measurement of carrier frequencies for many diseases. As the resultant rank-ordering of carrier frequencies impacts the design and prioritization of screening programs, the accuracy of this ranking is a public health concern.


A total of 23,453 individuals from many obstetric, genetics, and infertility clinics were referred for routine recessive disease carrier screening. Multiplex carrier screening was performed and results were aggregated for this study.


Twenty-four percent of individuals were identified as carriers for at least one of 108 disorders, and 5.2% were carriers for multiple disorders. We report tabulations of carrier frequency by self-identified ethnicity and disease.


To our knowledge, this study of a large, ethnically diverse clinical sample provides the most accurate measurements to date of carrier frequencies for hundreds of recessive alleles. The study also yields information on the clinical considerations associated with routine use of expanded panels and provides support for a pan-ethnic screening paradigm that minimizes the use of “racial” categories by the physician, as recommended by recent guidelines.

Genet Med 2013:15(3):178–186


carrier frequency; carrier screening; genetic testing; pan-ethnic; recessive disease


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  1. Department of Genetics, Counsyl, South San Francisco, California, USA

    • Gabriel A. Lazarin,
    • Imran S. Haque,
    • Shivani Nazareth,
    • Kevin Iori,
    • A. Scott Patterson,
    • Jessica L. Jacobson,
    • John R. Marshall,
    • William K. Seltzer,
    • Eric A. Evans &
    • Balaji S. Srinivasan
  2. Department of Pathology, New York University, New York, New York, USA

    • Jessica L. Jacobson
  3. Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA

    • John R. Marshall
  4. Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut, USA

    • Pasquale Patrizio
  5. Department of Computer Science, Stanford University, Stanford, California, USA

    • Balaji S. Srinivasan
  6. Department of Statistics, Stanford University, Stanford, California, USA

    • Balaji S. Srinivasan

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