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Abstract: TH-PO369

Experience With Genetic Testing at a Large Polycystic Kidney Disease-Focused Program

Session Information

Category: Genetic Diseases of the Kidneys

  • 1101 Genetic Diseases of the Kidneys: Cystic

Authors

  • Chao, Allen, University of California San Francisco, San Francisco, California, United States
  • Gao, Ying, University of California San Francisco, San Francisco, California, United States
  • Jiang, Jordan, University of California San Francisco, San Francisco, California, United States
  • Etwaru, Diana, University of California San Francisco, San Francisco, California, United States
  • Osunde, Adesuwa N., University of California San Francisco, San Francisco, California, United States
  • Varanasi, Laalasa, University of California San Francisco, San Francisco, California, United States
  • Gluck, Stephen L., University of California San Francisco, San Francisco, California, United States
  • Loeb, Gabriel, University of California San Francisco, San Francisco, California, United States
  • Park, Meyeon, University of California San Francisco, San Francisco, California, United States
Background

We are a center that provides specialized care for patients with autosomal dominant polycystic kidney disease (PKD). Genetic testing in PKD has historically been used in the context of diagnostic uncertainty, pre-transplant evaluation, and pre-implantation genetic testing for mutation for in vitro fertilization. Since development of the Renasight panel test (Natera) in April 2020, we have offered genetic testing more routinely due to greater accessibility and ease of testing. We sought to determine how many patients seen in our center underwent genetic testing, results of testing, and differences between individuals who desired testing and those who declined.

Methods

We searched our electronic medical record to determine how many patients with PKD were seen in clinic appointments since the Renasight test became available (May 1, 2020). We described the range of genetic test results in the PKD1 and PKD2 genes and compared characteristics of individuals with and without genetic testing using t-test and chi-square.

Results

225 patients in total were identified. 79 patients had genetic testing. 76 underwent Renasight panel test; 3 already had genetic testing by other companies (GeneDx, Prevention Genetics, Athena Diagnostics). 39 (49.4%) were women. 48 (60.8%) were White, 7 (8.9%) were Black, 16 (20.3%) were Asian, 2 (2.5%) were Latinx, 6 (7.6%) were another race category. Age range was 22 to 84 years and median age (IQR) was 47 (36, 59). Out of the 76 Renasight tests, 47 (61.8%) were positive for mutations in PKD1 (39) or PKD2 (8). 14 (18%) were noted to have variants of uncertain significance in either of these genes. Of the known pathogenic mutations, 33 (44%) were truncating, 24 (32%) were nontruncating. The majority of mutations were nonsense (35%) and missense (30%). Individuals with genetic testing had a lower presence of family history of PKD than those without genetic testing (63% v 80%, p=0.01). There was no difference in age or gender between groups.

Conclusion

Genetic testing for PKD1 and PKD2 has become more accessible due to development of the Renasight panel test. Individuals with PKD with no family history especially seem motivated to undergo testing. Future work to understand motivators and barriers to genetic testing as well as understanding of costs to patients associated with testing should be pursued.