What Are You Missing? Expanded Genetic Carrier Testing Identifies At-risk Couples [17L]

Abstract

INTRODUCTION: Expanded genetic carrier testing allows couples to determine their reproductive risk for genetic disorders regardless of an individual's ancestral background or geographic origin. METHODS: As part of routine laboratory management, requisitions were reviewed for information on reproductive partners. Our database was queried for names of reproductive partners, and demographic information was cross-referenced to determine validity of the matched sample. A retrospective analysis was performed for known matched reproductive pairs and descriptive analysis regarding ethnicity, test ordered, and results of genetic carrier testing on each matched pair was performed. RESULTS: Data was entered for 1,585 reproductive partners; after validation and confirmation of carrier testing performed, 783 known reproductive pairs were confirmed. Forty-six (5.9%) couples were found to be at risk for the same autosomal recessive disorder(s), including: hereditary hemochromatosis (20), cystic fibrosis (10), familial Mediterranean fever (6), hemoglobinopathies (5), spinal muscular atrophy (3), primary congenital glaucoma (2), and phenylalanine hydroxylase deficiency (PKU) (1). An additional 1% were potentially at increased risk for the same genetic disorder due to indeterminate results by enzyme analysis or hemoglobin electrophoresis. CONCLUSION: Our study identified 6.9% of couples to be at increased risk to have an affected child, and demonstrates the importance of testing partners to allow for reproductive decision-making. Additionally, 28 (61%) of these couples were found to be carriers of disorders only included on expanded carrier testing panels. Therefore, testing patients with an expanded pan-ethnic panel will identify more couples at risk for disorders that would be missed by current ethnicity-based recommendations.