Discovery of BRCA1/BRCA2 founder variants by haplotype analysis.

A significant number of hereditary breast or ovarian cancers are caused by germline variants, mostly BRCA1/BRCA2 genes. Because genetic predispositions vary by ethnicity, several studies have reported founder variants of BRCA1/BRCA2 genes. Such founder variants were reported primarily based on their relevant population frequencies. We reviewed the variant data relating to BRCA1 and BRCA2 genes from January 2012 to March 2019 at Samsung Medical Center, Seoul, Korea. Among the cases with pathogenic variants (PVs) or likely pathogenic variants (LPVs), we defined recurrent variants as those found in more than five unrelated patients. Using single nucleotide polymorphisms, we analyzed patient haplotypes. There were 14 recurrent variants in the BRCA1 gene and seven variants in the BRCA2 gene. Of note, three variants in each gene were primarily detected in Korean populations. Among them, the c.5339T>C (p.Leu1780Pro) BRCA1 variant had a long block sized 74.5 kb. In BRCA2, the c.1399A>T (p.Lys467*) variant had a long block sized 35.5 kb. We suggest that BRCA1 c.5339T>C (p.Leu1780Pro) and BRCA2 c.1399A>T (p.Lys467*) are founder variants of the Korean population. These two recurrent variants were ethnicity-prevalent, primarily found in Korean populations, and the sizes of the linkage disequilibrium blocks are longer than others.

Statins Enhance the Molecular Response in Chronic Myeloid Leukemia when Combined with Tyrosine Kinase Inhibitors.

Previous studies have suggested that statins can be repurposed for cancer treatment. However, the therapeutic efficacy of statins in chronic myeloid leukemia (CML) has not yet been demonstrated. In this study, we retrospectively evaluated the outcomes of 408 CML patients who underwent imatinib therapy. The deep molecular response rates in patients treated with the statin/TKI combination were significantly higher than those in patients treated with TKI alone (p = 0.0016). The statin/TKI combination exerted potent cytotoxic effects against wild-type and ABL1 mutant CML, BaF3, and K562/T315I mutant cells. Furthermore, the statin/TKI combination additively inhibited the colony-forming capacity of murine CML-KLS+ cells in vitro. In addition, we examined the additive growth-inhibitory effects of the statin/tyrosine kinase inhibitor (TKI) combination against CML patient-derived CD34+ cells. The growth-inhibitory effects of the statin/imatinib combination against CD34+/CML primary cells were higher than those against CD34+/Norm cells (p = 0.005), suggesting that the combination of rosuvastatin and imatinib exerted growth-inhibitory effects against CML CD34+ cells, but not against normal CD34+ cells. Furthermore, results from RNA sequencing of control and statin-treated cells suggested that statins inhibited c-Myc-mediated and hematopoietic cell differentiation pathways. Thus, statins can be potentially repurposed to improve treatment outcomes in CML patients when combined with TKI therapy.

Whole-genome sequencing reveals KRTAP1-1 as a novel genetic variant associated with antidepressant treatment outcomes.

Achieving remission following initial antidepressant therapy in patients with major depressive disorder (MDD) is an important clinical result. Making predictions based on genetic markers holds promise for improving the remission rate. However, genetic variants found in previous genetic studies do not provide robust evidence to aid pharmacogenetic decision-making in clinical settings. Thus, the objective of this study was to perform whole-genome sequencing (WGS) using genomic DNA to identify genetic variants associated with the treatment outcomes of selective serotonin reuptake inhibitors (SSRIs). We performed WGS on 100 patients with MDD who were treated with escitalopram (discovery set: 36 remitted and 64 non-remitted). The findings were applied to an additional 553 patients with MDD who were treated with SSRIs (replication set: 185 remitted and 368 non-remitted). A novel loss-of-function variant (rs3213755) in keratin-associated protein 1-1 (KRTAP1-1) was identified in this study. This rs3213755 variant was significantly associated with remission following antidepressant treatment (p = 0.0184, OR 3.09, 95% confidence interval [CI] 1.22-7.80 in the discovery set; p = 0.00269, OR 1.75, 95% CI 1.22-2.53 in the replication set). Moreover, the expression level of KRTAP1-1 in surgically resected human temporal lobe samples was significantly associated with the rs3213755 genotype. WGS studies on a larger sample size in various ethnic groups are needed to investigate genetic markers useful in the pharmacogenetic prediction of remission following antidepressant treatment.

Heritability estimates of individual psychological distress symptoms from genetic variation.

BACKGROUND: Psychological distress symptoms are associated with an increased risk of psychiatric disorders and medical illness. Although psychological distress is influenced by environmental factors, such as socioeconomic status, lifetime events, or interpersonal relationships, substantial interindividual variation also exists. However, heritability and genetic determinants of distress are poorly understood. METHODS: In the Korean Genome and Epidemiology Study sample (n = 12,680), we estimated the heritability of individual psychological distress symptoms using the GCTA-REML method and carried out a genome-wide association study of individual psychological distress symptoms showing significant heritability. RESULTS: We found three psychological distress items showing significant heritability: subjective well-being (9%), fatigue and appetite (11%), and enjoying daily life (8%). Additionally, we found genome-wide significant associations of rs6735649 located between STEAP3 and C1QL2 on chromosome 2 with subjective well-being (P = 1.32 × 10-8, odds ratio [OR] = 1.18, 95% confidence interval [CI]: 1.12-1.25) and rs35543418 located between SYT16 and KCNH5 on chromosome 14 with enjoying daily life (P = 1.33 × 10-8, OR = 1.59, 95% CI: 1.35-1.86). LIMITATIONS: The lack of replication in independent cohorts and longitudinal assessment of distress may limit generalizability. CONCLUSIONS: Our results indicate that distress symptoms are partly heritable. Further analysis in larger cohorts investigating gene-environment interactions is required to identify genetic variants that explain the proportion of variation in distress.