The vascular system in plants, which comprises xylem, phloem and vascular stem cells, originates from provascular cells and forms a continuous network throughout the plant body. Although various aspects of vascular development have been extensively studied, the early process of vascular development remains largely unknown. LONESOME HIGHWAY (LHW), which encodes an atypical basic helix-loop-helix (bHLH) transcription factor, plays an essential role in establishing vascular cells. Here, we report the analysis of LHW homologs in relation to vascular development. Three LHW homologs, LONESOME HIGHWAY LIKE 1-3 (LHL1-LHL3), were preferentially expressed in the plant vasculature. Genetic analysis indicated that, although the LHL3 loss-of-function mutant showed no obvious phenotype, the lhw lhl3 double mutant displayed more severe phenotypic defects in the vasculature of the cotyledons and roots than the lhw single mutant. Only one xylem vessel was formed at the metaxylem position in lhw lhl3 roots, whereas the lhw root formed one protoxylem and one or two metaxylem vessels. Conversely, overexpression of LHL3 enhanced xylem development in the roots. Moreover, N-1-naphthylphthalamic acid caused ectopic LHL3 expression in accordance with induced auxin maximum. These results suggest that LHL3 plays a positive role in xylem differentiation downstream of auxin.

Genetic counselors routinely assess and understand clients’ needs at the beginning of a session. Attending a genetic counseling session with or without companions is an objective sign that genetic counselors can easily notice. This study focused on clients’ reasons for their accompaniment status for genetic counseling, which we categorize into attending with or without a companion(s). A questionnaire survey and interviews were conducted using snowball sampling, starting with the chief executive officer (CEO) of the Japanese hereditary breast and ovarian cancer (HBOC) support group. Of 32 participants, 19 continued with an in‐depth interview after answering the questionnaire. Five themes were identified from the interview: (1) personal confidence, (2) decision‐making style, (3) family members’ habits and time availability, (4) considerations and conflicts with family members, and (5) healthcare provider's suggestion. Our data suggested that the clients expected their companion(s) to play certain roles. This indicates that the reasons of accompaniment status will be helpful for genetic counselors to understand both clients’ and their families’ motivations, personalities, habits, and psychosocial backgrounds. In a high‐context culture such as that of Japan, accompaniment status may be a helpful sign to understand clients’ true worries. In addition, some companions may be future clients in genetic counseling, due to the genetic nature of the disease. In conclusion, our study indicated that it is important for genetic counselors to record accompaniment status before the initial genetic counseling and to pay attention to its reasons at the beginning of the session, which may lead them to understand the client's psychosocial background to facilitate better client‐centered genetic counseling.

Objective: An association between the Moyamoya disease susceptible gene ring finger protein 213 (RNF213) variant and ischemic stroke and coronary artery disease has been suggested in case-control studies. We aimed to investigate the possible association between the RNF213 variant and the incidence of cardiovascular disease in a general population. Methods:The study participants consisted of 9153 Japanese community residents without history of cardiovascular disease. The clinical parameters employed in this analysis were observed at baseline between 2008 and 2010. The RNF213 p.R4859K variant was determined by TaqMan probe assay and then confirmed by Sanger sequencing.Results: During 8.52 years follow-up period, we observed 214 incident cases of cardiovascular diseases (99 total stroke cases, 119 major adverse cardiac event cases, including 4 cases of both). The incidence rate was higher for the variant allele carriers (120 cases; incidence rate, 71.0 per 10 000 person-years) than for the homozygotes of the wild-type allele (26.9), and the group differences achieved statistical significance (P ¼ 0.009). Although the RNF213 variant was also associated with systolic blood pressure (dominant model: coefficient of 8.19 mmHg; P < 0.001), the Cox regression analysis adjusted for major covariates including systolic blood pressure identified the RNF213 variant as an independent determinant for cardiovascular disease (hazard ratio of 3.41, P ¼ 0.002) and major adverse cardiac event (hazard ratio of 3.80, P ¼ 0.010) but not with total stroke (P ¼ 0.102). Conclusion:The Moyamoya disease susceptible RNF213 variant was associated with blood pressure and the incidence of cardiovascular disease in a Japanese general population.

10615 Background: Genetic testing for pathogenic germline variants (PGVs) is performed to identify hereditary cancer syndromes (HCS) and to evaluate the application of targeted therapies in clinical oncology. Multi-gene panels (MGPs) have become popular for identifying HCS; however, their clinical utility in therapeutic applications and confirmatory germline testing for presumed PGVs and in cascade testing are not well established. Methods: BRANCH [UMIN000046085] is a multicenter clinical study to confirm PGVs in: i) patients with advanced solid tumors in whom a presumed PGV has been detected by comprehensive genomic profiling (CGP) (cohort A); ii) patients who received a germline BRCA (gBRCA) test (cohort D); and iii) first-degree relatives of patients with PGVs identified in this study (cohort C). PGVs were examined in 35 HCS genes using an MGP combined with digital multiple-ligation-dependent probe amplification. Results: MGP results were available for 75 patients in cohort A and 83 in cohort D (3 February 2023). The most common cancer in cohort A was colorectal cancer (13%) followed by ovarian (12%) and breast (11%) cancers. Of 103 tested presumed PGVs, 46 (45%) were confirmed as PGVs, with the highest germline conversion rates in BRCA1 (8/8, 100%), followed by PALB2 (5/6, 83%) and BRCA2 (15/19, 79%) among the genes tested in ≥3 patients. In tissue-based CGP, true PGVs had a higher variant allelic frequency (median 55.7% [range, 31.9-96.8]) than non-PGVs (37.0% [9.3-86.9]). In cohort D, 61 (74%) patients had breast cancer, including one with both breast and ovarian cancers. All BRCA PGVs identified by gBRCA test were identified by MGP in 28 BRCA-positive patients. Intriguingly, among 55 patients (66%) in whom no BRCA PGV was detected by gBRCA test, non-BRCA PGVs were identified in 6 (11%) patients (2 PALB2 and 1 each of ATM, CHEK2, MSH2 [large deletion], and TP53). Thirty relatives in 18 pedigrees received MGP-based cascade testing in cohort C. The most frequent target genes were BRCA2 followed by BRCA1 and PALB2. The same PGVs as the probands were confirmed in 11 (37%) individuals and novel PGVs were identified in 2 (7%) relatives, leading to double PGVs in homologous recombination genes ( PALB2+ BRCA2 and BRCA2+ ATM), respectively . Conclusions: MGP successfully determined germline variants among presumed PGVs identified by CGP in patients with advanced solid tumors, and detected non-BRCA PGVs in 10% of gBRCA-negative patients. Furthermore, MGP-based cascade testing has the potential to identify other PGVs in addition to those detected in the probands. Clinical trial information: UMIN000046085 .