Date of Award

1-1-2011

Document Type

Campus Access Thesis

Department

Genetic Counseling

First Advisor

Peggy Walker

Abstract

Purpose: Since its introduction into the clinical arena in 2004, chromosomal microarray (CMA) testing has rapidly evolved into a powerful diagnostic test and changed pediatric genetic practice. In the past year several investigators have recommended that microarray testing be included in the first-tier of testing for pediatric patients with autism spectrum disorders, intellectual disability, developmental delay, and multiple congenital anomalies (Manning, 2010; Miller et al., 2010; Shen et al., 2010). While microarray technology has become firmly embedded in routine clinical practice, no guidelines currently exist to standardize what information should be discussed with patients prior to testing in order to ensure fully informed consent. The purpose of this study was to assess pediatric genetic counselors' current methods of informing and consenting families for microarray testing. We sought to understand barriers to informing and consenting families, as well as to learn from the first-hand experiences of pediatric genetic counselors offering microarray testing to families. Method: Practicing pediatric genetic counselors (N=92) from across the United States completed an online survey designed to address the goals of this study. Results: Of all respondents, 88% reported that their practice does not have established statements of information about microarrays. However, the results of our study clearly delineated eight topics that are always or usually discussed with families prior to microarray testing, including the following: the test is designed to detect changes in copy number (100%); how the patient will be contacted with his/her results (99%); the test name (97%); the test may not reveal the change(s) that are causing the disorder in your child/family (96%); parents may decide to have their child tested or they may decline testing (88%); the test looks at your child's entire genome (86%); parents may need to be tested to help interpret their child's result (84%); and the possible results including: positive, negative, variant of uncertain significance, or inconclusive (82%). Similarly, our results illuminated five topics that are rarely or never being addressed with pediatric families prior to microarray testing. These include: consanguinity may be revealed (76%); the test may reveal that the patient is at an increased risk for cancer or an adult-onset condition (74%); if parents are tested, non-paternity may be revealed (73%); specific detection rates for the array platform being used (71%); and the patient's sample may be de-identified and used for research (71%). Over 80% of respondents agreed that the information presented during the process of informing and consenting families for pediatric microarray testing should be consistent regardless of who is presenting the information. However, standardization was not reflected in our data regarding the current practices of genetic counselors. Conclusions: As genetic testing methodologies continue to evolve in sophistication, genetic counselors and other healthcare providers must develop ways to inform families about microarray testing in a manner that is comprehensive enough to obtain fully informed consent, yet manageable within the existing parameters of clinical practice. Establishing a set of standards by defining what topics are necessary for any healthcare provider to include in a pretest discussion of microarray testing would help ensure that all families are receiving complete and accurate information prior to their decision to undergo CMA testing.

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