Pathogenic variants in affected and unaffected individuals from Indonesian familial cancer: a multigene panel analysis

The precise prevalence of pathogenic gene variants in high or moderate penetrance genes associated with hereditary cancer in Indonesia remains undetermined. Furthermore, the criteria for prioritizing individuals for genetic testing are not well-defined. This study examined gene variants in Indonesian familial cancer among both affected and unaffected individuals. A total of 159 participants from 55 families with a history of cancer, including affected (N = 61) and unaffected (N = 98) individuals, underwent genetic testing using germline DNA with the 113 multigene panel. Various cancer types were identified, including breast (N = 46), ovarian (N = 3), retinoblastoma (N = 3), colon (N = 2), uterine (N = 2), and other cancers (N = 1 each) such as lung, prostate, thyroid, bladder, and testicular seminoma. Pathogenic variants were identified in 10 (18.8%) of the 55 families, with 6 (60%) confirmed as hereditary cancer families. These variants were detected in 14 affected individuals, involving 8 distinct genes (BRCA1, BRCA2, MUTYH, PALB2, RAD51D, VHL, ERCC4, and RB1), and the prevalence was significantly higher in cases of early-onset (< 40 years) compared to late-onset cancer (53.8% vs. 14.6%, p < 0.01). These findings confirm that several pathogenic gene variants in familial cancer in Indonesia are inherited. This data is crucial for both affected and unaffected family members to facilitate appropriate management strategies.