Genetic Misdiagnoses and the Potential for Health Disparities

TY - JOUR

T1 - Genetic Misdiagnoses and the Potential for Health Disparities

AU - Manrai, Arjun K

AU - Funke, Birgit H

AU - Rehm, Heidi L

AU - Olesen, Morten S

AU - Maron, Bradley A

AU - Szolovits, Peter

AU - Margulies, David M

AU - Loscalzo, Joseph

AU - Kohane, Isaac S

PY - 2016/8/18

Y1 - 2016/8/18

N2 - BACKGROUND For more than a decade, risk stratification for hypertrophic cardiomyopathy has been enhanced by targeted genetic testing. Using sequencing results, clinicians routinely assess the risk of hypertrophic cardiomyopathy in a patient's relatives and diagnose the condition in patients who have ambiguous clinical presentations. However, the benefits of genetic testing come with the risk that variants may be misclassified. METHODS Using publicly accessible exome data, we identified variants that have previously been considered causal in hypertrophic cardiomyopathy and that are overrepresented in the general population. We studied these variants in diverse populations and reevaluated their initial ascertainments in the medical literature. We reviewed patient records at a leading genetic- Testing laboratory for occurrences of these variants during the near-decade-long history of the laboratory. RESULTS Multiple patients, all of whom were of African or unspecified ancestry, received positive reports, with variants misclassified as pathogenic on the basis of the understanding at the time of testing. Subsequently, all reported variants were recategorized as benign. The mutations that were most common in the general population were significantly more common among black Americans than among white Americans (P<0.001). Simulations showed that the inclusion of even small numbers of black Americans in control cohorts probably would have prevented these misclassifications. We identified methodologic shortcomings that contributed to these errors in the medical literature. CONCLUSIONS The misclassification of benign variants as pathogenic that we found in our study shows the need for sequencing the genomes of diverse populations, both in asymptomatic controls and the tested patient population. These results expand on current guidelines, which recommend the use of ancestry-matched controls to interpret variants. As additional populations of different ancestry backgrounds are sequenced, we expect variant reclassifications to increase, particularly for ancestry groups that have historically been less well studied.

AB - BACKGROUND For more than a decade, risk stratification for hypertrophic cardiomyopathy has been enhanced by targeted genetic testing. Using sequencing results, clinicians routinely assess the risk of hypertrophic cardiomyopathy in a patient's relatives and diagnose the condition in patients who have ambiguous clinical presentations. However, the benefits of genetic testing come with the risk that variants may be misclassified. METHODS Using publicly accessible exome data, we identified variants that have previously been considered causal in hypertrophic cardiomyopathy and that are overrepresented in the general population. We studied these variants in diverse populations and reevaluated their initial ascertainments in the medical literature. We reviewed patient records at a leading genetic- Testing laboratory for occurrences of these variants during the near-decade-long history of the laboratory. RESULTS Multiple patients, all of whom were of African or unspecified ancestry, received positive reports, with variants misclassified as pathogenic on the basis of the understanding at the time of testing. Subsequently, all reported variants were recategorized as benign. The mutations that were most common in the general population were significantly more common among black Americans than among white Americans (P<0.001). Simulations showed that the inclusion of even small numbers of black Americans in control cohorts probably would have prevented these misclassifications. We identified methodologic shortcomings that contributed to these errors in the medical literature. CONCLUSIONS The misclassification of benign variants as pathogenic that we found in our study shows the need for sequencing the genomes of diverse populations, both in asymptomatic controls and the tested patient population. These results expand on current guidelines, which recommend the use of ancestry-matched controls to interpret variants. As additional populations of different ancestry backgrounds are sequenced, we expect variant reclassifications to increase, particularly for ancestry groups that have historically been less well studied.

KW - Adolescent

KW - Adult

KW - African Americans/genetics

KW - Aged

KW - Asian Americans/genetics

KW - Cardiomyopathy, Hypertrophic/genetics

KW - Child

KW - European Continental Ancestry Group/genetics

KW - Exome

KW - False Positive Reactions

KW - Genetic Predisposition to Disease

KW - Genetic Testing

KW - Genetic Variation

KW - Genotype

KW - Health Status Disparities

KW - Hispanic Americans/genetics

KW - Humans

KW - Middle Aged

KW - Mutation

KW - Sequence Analysis, DNA

KW - United States

KW - Young Adult

U2 - 10.1056/NEJMsa1507092

DO - 10.1056/NEJMsa1507092

M3 - Journal article

C2 - 27532831

SN - 0028-4793

VL - 375

SP - 655

EP - 665

JO - New England Journal of Medicine

JF - New England Journal of Medicine

IS - 7

ER -