Natural History and Developmental Trajectories of Individuals With Disease-Causing Variants in STXBP1.

BACKGROUND AND OBJECTIVES: Pathogenic variants in STXBP1 are among the major genetic causes of neurodevelopmental disorders. Despite the increasing number of individuals diagnosed without a history of epilepsy, little is known about the natural history and developmental trajectories in this subgroup and endpoints for future therapeutic studies are limited to seizure control. METHODS: We performed a cross-sectional retrospective study using standardized questionnaires for clinicians and caregivers of individuals with STXBP1-related disorders capturing medical histories, genetic findings, and developmental outcomes. Motor and language function were assessed using Gross Motor Function Classification System (GMFCS) scores and a speech impairment score and were compared within and across clinically defined subgroups. RESULTS: We collected data of 71 individuals with STXBP1-related disorders, including 44 previously unreported individuals. Median age at inclusion was 5.3 years (interquartile range 3.5-9.3) with the oldest individual aged 43.8 years. Epilepsy was absent in 18/71 (25%) of individuals. The range of developmental outcomes was broad, including 2 individuals presenting with close to age-appropriate motor development. Twenty-nine of 61 individuals (48%) were able to walk unassisted, and 24/69 (35%) were able to speak single words. Individuals without epilepsy presented with a similar onset and spectrum of phenotypic features but had lower GMFCS scores (median 3 vs 4, p < 0.01) than individuals with epilepsy. Individuals with epileptic spasms were less likely to walk unassisted than individuals with other seizure types (6% vs 58%, p < 0.01). Individuals with early epilepsy onset had higher speech impairment scores (p = 0.02) than individuals with later epilepsy onset. DISCUSSION: We expand the spectrum of STXBP1-related disorders and provide clinical features and developmental trajectories in individuals with and without a history of epilepsy. Individuals with epilepsy, in particular epileptic spasms, and neonatal or early-onset presented with less favorable motor and language functional outcomes compared with individuals without epilepsy. These findings identify children at risk for severe disease and can serve as comparator for future interventional studies in STXBP1-related disorders.

PERFORM: a non-interventional study assessing the patients' treatment starting with 1L palbociclib in HR+/HER2- ABC.

The prospective, non-interventional PERFORM study describes and analyzes the effectiveness of palbociclib in combination with endocrine therapy (aromatase inhibitor or fulvestrant) as first-line treatment for patients with locally advanced or metastatic HR+/HER2- breast cancer in the real-world setting in Germany and Austria. PERFORM will reflect current patient characteristics and routine treatment patterns including treatment sequences and time to subsequent (chemo)therapy. Besides, second-line treatment effectiveness and patient-relevant end points such as longitudinal patient-reported outcome measurements beyond disease progression will be analyzed. Accounting for the heterogenous real-world patient population, data on clinicopathologic subgroups underrepresented in clinical trials such as elderly or male will be analyzed. Taken together, PERFORM will close knowledge gaps from clinical trials in real world.

Palbociclib in combination with endocrine therapy is the standard first-line treatment for patients with advanced HR+/HER2- breast cancer. Data from clinical trials have shown high response rates and good tolerability. To support these data and close potential knowledge gaps, we conduct the multicenter, observational PERFORM study to evaluate the effectiveness and patient-reported outcomes in patients with advanced HR+/HER2- breast cancer treated with endocrine-based palbociclib therapy in routine clinical practice in Germany. Clinical Trial Registration: NCT04767594 (ClinicalTrials.gov) Sponsor: Pfizer Pharma GmbH, Linkstraße 10, D-10785 Berlin, Germany.

Genetic overlap between dystonia and other neurologic disorders: A study of 1,100 exomes.

INTRODUCTION: Although shared genetic factors have been previously reported between dystonia and other neurologic conditions, no sequencing study exploring such links is available. In a large dystonic cohort, we aimed at analyzing the proportions of causative variants in genes associated with disease categories other than dystonia. METHODS: Gene findings related to whole-exome sequencing-derived diagnoses in 1100 dystonia index cases were compared with expert-curated molecular testing panels for ataxia, parkinsonism, spastic paraplegia, neuropathy, epilepsy, and intellectual disability. RESULTS: Among 220 diagnosed patients, 21% had variants in ataxia-linked genes; 15% in parkinsonism-linked genes; 15% in spastic-paraplegia-linked genes; 12% in neuropathy-linked genes; 32% in epilepsy-linked genes; and 65% in intellectual-disability-linked genes. Most diagnosed presentations (80%) were related to genes listed in ≥1 studied panel; 71% of the involved loci were found in the non-dystonia panels but not in an expert-curated gene list for dystonia. CONCLUSIONS: Our study indicates a convergence in the genetics of dystonia and other neurologic phenotypes, informing diagnostic evaluation strategies and pathophysiological considerations.

Awareness and Availability of Routine Germline BRCA1/2 Mutation Testing in Patients with Advanced Breast Cancer in Germany.

Introduction: Diagnostic testing of germline mutations in breast cancer susceptibility genes 1 or 2 (gBRCA1/2) in patients with human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer (ABC; locally advanced or metastatic breast cancer) is necessary to assess eligibility for poly(ADP-ribose) polymerase inhibitors (PARPi). We investigated awareness, clinical practice, and the availability of gBRCA1/2 mutation testing in the German outpatient oncology setting. Methods: Office-based oncologists completed a 23-item online survey. Responses were evaluated collectively and by center type. Results: Of 50 oncologists, 33 and 17 were medical and gynecological oncologists, respectively. Oncologists treated a median of 65 (range 14-350) patients with ABC per year. The strongest decision factors to initiate gBRCA1/2 mutation testing were: patient's known family history of gBRCA1/2 mutation-related cancer(s), guideline recommendations, and triple-negative breast cancer (TNBC). In routine practice, 86% of oncologists tested for gBRCA1/2 mutations. Most oncologists (76-98%) reported testing patients with a known family history of gBRCA1/2 mutation-related cancer(s) irrespective of receptor status. For unknown family history, 92% of oncologists reported testing patients with advanced TNBC versus 30% for HR+/HER2- ABC. Oncologists (66%) rated the awareness of therapeutic relevance of gBRCA1/2 mutation testing for targeted treatment selection as good to satisfactory; 22% rated awareness as poor to in-sufficient. Conclusion: Diagnostic gBRCA1/2 mutation testing in patients with HER2- ABC is available and routinely performed in Germany's outpatient oncology setting. However, specific patient subgroups were not routinely tested despite therapeutic indications. Given PARPi availability, opportunities exist to improve testing rates especially for patients with HR+/HER2- ABC without a known family history of gBRCA1/2 mutation-related cancer(s).

Final results from IMPROVE: a randomized, controlled, open-label, two-arm, cross-over phase IV study to determine patients' preference for everolimus in combination with exemestane or capecitabine in combination with bevacizumab in advanced HR-positive, HER2-negative breast cancer.

BACKGROUND: The objective of the IMPROVE study was patients' preference for either endocrine-based therapy or combined chemo- and anti-angiogenic therapy in advanced HR-positive/HER2-negative breast cancer. METHODS: In this randomized, cross-over phase IV study, 77 patients were recruited in 26 sites in Germany. Patients were randomized 1:1 to receive either capecitabine plus bevacizumab (Cap+Bev) as first-line therapy followed by cross-over to everolimus plus exemestane (Eve+Exe) as second-line therapy (Arm A) or the reverse sequence (Arm B). The primary endpoint was patients' preference for either regimen, assessed by the Patient Preference Questionnaire 12 weeks after cross-over. Key secondary endpoints included progression-free survival (PFS), overall survival (OS), safety, and quality of life (QoL). RESULTS: 61.5% of patients preferred Cap+Bev (p = 0.1653), whereas 15.4% preferred Eve+Exe and 23.1% were indecisive. Physicians showed a similar tendency towards Cap+Bev (58.1%) as the preferred regimen versus Eve+Exe (32.3%). Median first-line PFS was longer for Cap+Bev than for Eve+Exe (11.1 months versus 3.5 months). Median second-line PFS was similar between Cap+Bev and Eve+Exe (3.6 months versus 3.7 months). Median OS was comparable between Arm A (28.8 months) and Arm B (24.7 months). 73.0% and 52.6% (first-/second-line, Cap+Bev) and 54.1% and 52.9% (first-/second-line, Eve+Exe) of patients experienced grade 3/4 TEAEs. No treatment-related deaths occurred. QoL and treatment satisfaction were not significantly different between arms or treatment lines. CONCLUSIONS: Patients tended to favor Cap+Bev over Eve+Exe, which was in line with physicians' preference. Cap+Bev showed superior first-line PFS, while QoL was similar in both arms. No new safety signals were reported. TRIAL REGISTRATION: EudraCT No: 2013-005329-22. Registered on 19 August 20.

Correction: Surveillance-Activated Defenses Block the ROS-Induced Mitochondrial Unfolded Protein Response.

[This corrects the article DOI: 10.1371/journal.pgen.1003346.].

Doxycyclin ameliorates a starvation-induced germline tumor in C. elegans daf-18/PTEN mutant background.

Managing available resources is a key necessity of each organism to cope with the environment. The nematode C. elegans responds to nutritional deprivation or harsh environmental conditions with a multitude of developmental adaptations, among them a starvation-induced quiescence at early larval development (L1). daf-18, the C. elegans homolog of the human tumor suppressor gene PTEN, is essential for the maintenance of survival and germline stem cell arrest during the L1 diapause. We show here that daf-18 mutants, independently to their failure to maintain G2 arrest of the primordial germ cells, develop a gonad phenotype after refeeding. This highly penetrant gonadal phenotype is further enhanced by a mutation in shc-1, encoding a protein homologous to the human adaptor ShcA. Features of this phenotype are a tumor-like phenotype encompassing hyper-proliferation of germ cell nuclei and disruption/invasion of the basement membrane surrounding the gonad. The penetrance of this phenotype is reduced by decreasing starvation temperature. In addition, it is also ameliorated in a dose-dependent way by exposure to the antibiotic doxycyclin either during starvation or during subsequent refeeding. Since, in eukaryotic cells, doxycyclin specifically blocks mitochondrial translation, our results suggest that daf-18 and shc-1;daf-18 mutants fail to adapt mitochondrial activity to reduced nutritional availability during early larval developing.

Mitochondrial stress: balancing friend and foe.

Mitochondria are vital organelles of the aerobic eukaryotic cell. Their dysfunction associates with aging and widespread age-related diseases. To sustain mitochondrial integrity, the cell executes a distinct set of stress-induced protective responses. The mitochondrial unfolded protein response (UPR(mt)) is a response of the cell to mitochondrial damage. The transcription factor ATFS-1 triggers UPR(mt) effector gene expression in the nucleus. The selective exclusion of ATFS-1 from mitochondrial import by stress-induced alterations of the mitochondrial membrane potential is currently discussed as key activation mechanism. Surprisingly, UPR(mt) activation often coincides with a lifespan extension in Caenorhabditis elegans and the same has recently been reported for mammalian cells. This review summarizes the current model of the UPR(mt), its inducers, and its crosstalk with other cellular stress responses. It focuses on the role of mitochondrial function as a regulator of aging and longevity.

Surveillance-activated defenses block the ROS-induced mitochondrial unfolded protein response.

Disturbance of cellular functions results in the activation of stress-signaling pathways that aim at restoring homeostasis. We performed a genome-wide screen to identify components of the signal transduction of the mitochondrial unfolded protein response (UPR(mt)) to a nuclear chaperone promoter. We used the ROS generating complex I inhibitor paraquat to induce the UPR(mt), and we employed RNAi exposure post-embryonically to allow testing genes whose knockdown results in embryonic lethality. We identified 54 novel regulators of the ROS-induced UPR(mt). Activation of the UPR(mt), but not of other stress-signaling pathways, failed when homeostasis of basic cellular mechanisms such as translation and protein transport were impaired. These mechanisms are monitored by a recently discovered surveillance system that interprets interruption of these processes as pathogen attack and depends on signaling through the JNK-like MAP-kinase KGB-1. Mutation of kgb-1 abrogated the inhibition of ROS-induced UPR(mt), suggesting that surveillance-activated defenses specifically inhibit the UPR(mt) but do not compromise activation of the heat shock response, the UPR of the endoplasmic reticulum, or the SKN-1/Nrf2 mediated response to cytosolic stress. In addition, we identified PIFK-1, the orthologue of the Drosophila PI 4-kinase four wheel drive (FWD), and found that it is the only known factor so far that is essential for the unfolded protein responses of both mitochondria and endoplasmic reticulum. This suggests that both UPRs may share a common membrane associated mechanism.