ABSTRACT
Cincinnati Children's Hospital Medical Center (CCHMC) implemented a Genetic Counseling Clinic (GCC), where the appointment for a general genetics indication is conducted solely by a genetic counselor (GC). We conducted a retrospective chart review of 211 patient encounters scheduled in the GCC between January 1, 2022 and June 30, 2022 and collected patient demographics, wait time, appointment characteristics, referral indication, and clinical recommendations. To study impact on patient access, we compared patient demographics and appointment characteristics with 912 patient encounters scheduled in the General Genetics Clinic with a geneticist during the same time period. We found that there were not significant differences in patient demographics scheduled in the GCC as compared with the General Genetics Clinic with the exception of insurance type, where patients scheduled in the GCC were more likely to have private insurance. Patients scheduled in the GCC had a significantly shorter wait time, were more likely to complete their appointment, were more often new to the genetics division, and were more likely to be seen via telehealth (audio plus video or audio-only) as compared with patients scheduled in the General Genetics Clinic. The most common indications for patients scheduled in the GCC were post-test counseling (36.0%) followed by pre-test counseling and coordination of testing (22.3%), and first-line testing for autism, intellectual disability, and developmental delay (13.7%). Completed appointments in the GCC often resulted in the GC ordering genetic testing (67.5%). After genetic testing results were received, most patients (72.7%) did not require subsequent follow-up with the genetics division, thereby reducing burden to the medical genetics team. Our GCC increased access to genetic services and allowed GCs and clinical geneticists to better work at the top of their scope of practice.
ABSTRACT
Germline loss-of-function mutations in BRCA1 interacting protein C-terminal helicase 1 (BRIP1) are associated with ovarian carcinoma and may also contribute to breast cancer risk, particularly among patients who develop disease at an early age. Normal BRIP1 activity is required for DNA interstrand cross-link (ICL) repair and is thus central to the maintenance of genome stability. Although pathogenic mutations have been identified in BRIP1, genetic testing more often reveals missense variants, for which the impact on molecular function and subsequent roles in cancer risk are uncertain. Next-generation sequencing of germline DNA in 2,160 early-onset breast cancer and 1,199 patients with ovarian cancer revealed nearly 2% of patients carry a very rare missense variant (minor allele frequency < 0.0001) in BRIP1. This is 3-fold higher than the frequency of all rare BRIP1 missense alleles reported in more than 60,000 individuals of the general population (P < 0.0001, χ 2 test). Using CRISPR-Cas9 gene editing technology and rescue assays, we functionally characterized 20 of these missense variants, focusing on the altered protein's ability to repair ICL damage. A total of 75% of the characterized variants rendered the protein hypomorph or null. In a clinical cohort of >117,000 patients with breast and ovarian cancer who underwent panel testing, the combined OR associated with BRIP1 hypomorph or null missense carriers compared with the general population was 2.30 (95% confidence interval, 1.60-3.30; P < 0.0001). These findings suggest that novel missense variants within the helicase domain of BRIP1 may confer risk for both breast and ovarian cancer and highlight the importance of functional testing for additional variants. SIGNIFICANCE: Functional characterization of rare variants of uncertain significance in BRIP1 revealed that 75% demonstrate loss-of-function activity, suggesting rare missense alleles in BRIP1 confer risk for both breast and ovarian cancer.