Prenatal genetic counseling challenges with indeterminate SMA results

Area of Science:

• Genetics
• Neurology
• Medical Genetics

Background:

• Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder, with 95% of cases caused by homozygous deletion of the SMN1 gene.
• A [2+0] chromosome configuration, where an individual has two SMN1 gene copies on one chromosome and none on the other, complicates carrier screening and can lead to indeterminate results.
• The prevalence of [2+0] carriers is higher in African American and Hispanic populations, and SMA screening's inclusion in general population panels in 2017 increased indeterminate results.

Purpose of the Study:

• To understand the practices and challenges genetic counselors face when providing counseling for indeterminate SMA carrier screening results.
• To specifically examine these challenges within non-Ashkenazi Jewish (AJ) populations and across different regions in the United States and Canada.

Main Methods:

• A quantitative survey with open-response questions was administered to 49 prenatal genetic counselors in the United States and Canada.
• Responses were analyzed to identify common challenges and themes in counseling patients with indeterminate SMA results.

Main Results:

• Genetic counselors reported significant challenges, including negative patient emotions and misunderstandings from both patients and referring providers, regardless of geographic region.
• Key challenges fell into three categories: patient-related issues, referring provider-related issues, and the impact of the 2017 expansion of SMA carrier screening.
• Qualitative data underscored the difficulties in communicating complex genetic information and residual risk associated with indeterminate SMA screening results.

Conclusions:

• There is a clear need for enhanced provider education regarding indeterminate SMA results to improve counseling efficacy.
• Development of educational tools, such as visual aids, is recommended to assist counselors in explaining these complex results.
• Further research is necessary to explore the perspectives of patients and referring providers to develop comprehensive support strategies.