Effectiveness of expanded prenatal screening among consanguineous couples of Afghan descent

Objective

The American College of Medical Genetics recommends extensive carrier screening among consanguineous couples, yet limited information is available regarding its performance among specific populations. We describe the potential utility of a large expanded carrier screening panel (>500 genes) for Afghan couples with consanguinity.

Method

A retrospective chart review was conducted of all patients who reported consanguinity and had genetic counseling consultation between 2010 and 2021 at our institution.

Results

Thirty-six women of Afghan descent reported consanguinity. Nineteen (53%) did not have known autosomal recessive disease risk (no prior fetus/child with suspected syndrome), 11 (31%) had apparent disease risk (fetus/child with symptoms suggesting syndrome but no specific diagnosis), and six (17%) had known molecular diagnosis for a prior child with a recessive syndrome. Of the six women with known molecular diagnosis for prior child with syndrome, five had known pathogenic variants confirming a genetic disorder, and one had highly suspicious variant of uncertain significance in the family. Among these six, five (83%) could have been identified with a 787-gene prenatal carrier screening panel.

Conclusion

Large, expanded carrier screening panel appears to be an effective method for identifying disorders among consanguineous Afghan couples and should ideally be considered preconceptionally.