Clinical and laboratory genetic counselor attitudes on the reporting of variants of uncertain significance for multigene cancer panels.

Research suggests variants of uncertain significance (VUSs) present a variety of challenges for genetic counselors (GCs), nongenetics clinicians, and patients. Multigene cancer panels reveal more VUSs than single gene testing as a result of the increase in the number of genes being tested. This study surveyed 87 clinical cancer GCs involved with direct patient care and 19 laboratory GCs who provide guidance to clinicians regarding genetic test results about their attitudes on various options for the reporting of VUSs by laboratories for broad multigene cancer panels. Independent samples t-tests were utilized to compare the two groups. Based on a six-point Likert-type scale (1 = Strongly Disagree to 6 = Strongly Agree), clinical cancer GCs (M = 5.4; SD = 0.8) and laboratory GCs (M = 5.2; SD = 0.9) agreed overall that VUSs should be reported (p = 0.44; Cohen's d = 0.21). When asked about specific reporting options, both clinical cancer GCs (M = 1.9; SD = 1.1) and laboratory GCs (M = 2.1; SD = 1.4) disagreed that VUSs should be reported only for genes related to the indication for testing (p = 0.50; Cohen's d = 0.17). Overall, most GCs felt clinicians should not choose whether VUSs should be reported on genetic test results, with clinical cancer GCs (M = 1.9; SD = 1.3) feeling more strongly against it than laboratory GCs (M = 3.1; SD = 1.4; p = 0.002; Cohen's d = 0.88). Generally, GCs were more in favor of VUSs not being reported for population-based screening, with laboratory GCs (M = 4.7; SD = 0.8) agreeing more with that practice than clinical cancer GCs (M = 3.7; SD = 1.4; p = 0.001; Cohen's d = 0.80). Both clinical cancer GCs (M = 4.1; SD = 1.2) and laboratory GCs (M = 3.9; SD = 1.2) agreed additional guidelines on how to approach VUSs in clinical practice should be developed (p = 0.54; Cohen's d = 0.17). While most GCs supported the reporting of VUSs overall, our analyses suggest clinical cancer and laboratory GCs may have different attitudes toward specific VUS-related reporting options. Further research is needed to elucidate GC preferences to help inform best practices for the reporting of VUSs. The development of additional standardized guidelines on how to approach VUSs would further support clinical practice.

Autosomal recessive MFN2-related Charcot-Marie-Tooth disease with diaphragmatic weakness: Case report and literature review.

Pathogenic variants in the mitofusin 2 gene (MFN2) are the most common cause of autosomal dominant Charcot-Marie-Tooth (CMT2) disease, which is typically characterized by axonal sensorimotor neuropathy. We report on a 7-month-old white female with hypotonia, motor delay, distal weakness, and motor/sensory axonal neuropathy in which next-generation sequencing analysis identified compound heterozygous pathogenic variants (c.2054_2069_1170del and c.392A>G) in MFN2. A review of the literature reveals that sporadic and familial cases of compound heterozygous or homozygous pathogenic MFN2 variants have been infrequently described, which indicates that MFN2 can also be inherited in a recessive manner. This case highlights several clinical findings not typically associated with MFN2 pathogenic variants, including young age of onset and rapidly progressing diaphragmatic paresis that necessitated tracheostomy and mechanical ventilation, and adds to the growing list of features identified in autosomal recessive MFN2-related CMT2. Our patient with MFN2-related CMT2 expands the clinical and mutational spectrum of individuals with autosomal recessive CMT2 and identifies a new clinical feature that warrants further observation. © 2016 Wiley Periodicals, Inc.