Activity of osimeRTInib in non-small-cell lung Cancer with UNcommon epidermal growth factor receptor mutations: retrospective Observational multicenter study (ARTICUNO).

BACKGROUND: Osimertinib represents the standard of care for the treatment of advanced non-small-cell lung cancer (NSCLC) harboring classical epidermal growth factor receptor (EGFR) mutations, constituting 80%-90% of all EGFR alterations. In the remaining cases, an assorted group of uncommon alterations of EGFR (uEGFR) can be detected, which confer variable sensitivity to previous generations of EGFR inhibitors, overall with lower therapeutic activity. Data on osimertinib in this setting are limited and strongly warranted. PATIENTS AND METHODS: The ARTICUNO study retrospectively evaluated data on osimertinib activity from patients with advanced NSCLC harboring uEGFR treated in 21 clinical centers between August 2017 and March 2023. Data analysis was carried out with a descriptive aim. Investigators collected response data according to RECIST version 1.1 criteria. The median duration of response, progression-free survival (mPFS), and overall survival were estimated by the Kaplan-Meier method. RESULTS: Eighty-six patients harboring uEGFR and treated with osimertinib were identified. Patients with 'major' uEGFR, that is, G719X, L861X, and S768I mutations (n = 51), had an overall response rate (ORR) and mPFS of 50% and 9 months, respectively. Variable outcomes were registered in cases with rarer 'minor' mutations (n = 27), with ORR and mPFS of 31% and 4 months, respectively. Among seven patients with exon 20 insertions, ORR was 14%, while the best outcome was registered among patients with compound mutations including at least one classical EGFR mutation (n = 13). Thirty patients presented brain metastases (BMs) and intracranial ORR and mPFS were 58% and 9 months, respectively. Amplification of EGFR or MET, TP53 mutations, and EGFR E709K emerged after osimertinib failure in a dataset of 18 patients with available rebiopsy. CONCLUSION: The ARTICUNO study confirms the activity of osimertinib in patients with uEGFR, especially in those with compound uncommon-common mutations, or major uEGFR, even in the presence of BMs. Alterations at the E709 residue of EGFR are associated with resistance to osimertinib.

A genome screen of 35 bipolar affective disorder pedigrees provides significant evidence for a susceptibility locus on chromosome 15q25-26.

Bipolar affective disorder is a heritable, relatively common, severe mood disorder with lifetime prevalence up to 4%. We report the results of a genome-wide linkage analysis conducted on a cohort of 35 Australian bipolar disorder families which identified evidence of significant linkage on chromosome 15q25-26 and suggestive evidence of linkage on chromosomes 4q, 6q and 13q. Subsequent fine-mapping of the chromosome 15q markers, using allele frequencies calculated from our cohort, gave significant results with a maximum two-point LOD score of 3.38 and multipoint LOD score of 4.58 for marker D15S130. Haplotype analysis based on pedigree-specific, identical-by-descent allele sharing, supported the location of a bipolar susceptibility gene within the Z(max-1) linkage confidence interval of 17 cM, or 6.2 Mb, between markers D15S979 and D15S816. Non-parametric and affecteds-only linkage analysis further verified the linkage signal in this region. A maximum NPL score of 3.38 (P=0.0008) obtained at 107.16 cM (near D15S130), and a maximum two-point LOD score of 2.97 obtained at marker D15S1004 (affecteds only), support the original genome-wide findings on chromosome 15q. These results are consistent with four independent positive linkage studies of mood and psychotic disorders, and raise the possibility that a common gene for susceptibility to bipolar disorder, and other psychiatric disorders may lie in this chromosome 15q25-26 region.

Altered motor activity, exploration and anxiety in heterozygous neuregulin 1 mutant mice: implications for understanding schizophrenia.

Human genetic studies have shown that neuregulin 1 (NRG1) is a potential susceptibility gene for schizophrenia. Nrg1 influences various neurodevelopmental processes, which are potentially related to schizophrenia. The neurodevelopmental theory of schizophrenia suggests that interactions between genetic and environmental factors are responsible for biochemical alterations leading to schizophrenia. To investigate these interactions and to match experimental design with the pathophysiology of schizophrenia, we applied a comprehensive behavioural phenotyping strategy for motor activity, exploration and anxiety in a heterozygous Nrg1 transmembrane domain mutant mouse model (Nrg1 HET) using different housing conditions and age groups. We observed a locomotion- and exploration-related hyperactive phenotype in Nrg1 HETs. Increased age had a locomotion- and exploration-inhibiting effect, which was significantly attenuated in mutant mice. Environmental enrichment (EE) had a stimulating influence on locomotion and exploration. The impact of EE was more pronounced in Nrg1 hypomorphs. Our study also showed a moderate task-specific anxiolytic-like phenotype for Nrg1 HETs, which was influenced by external factors. The behavioural phenotype detected in heterozygous Nrg1 mutant mice is not specific to schizophrenia per se, but the increased sensitivity of mutant mice to exogenous factors is consistent with the pathophysiology of schizophrenia and the neurodevelopmental theory. Our findings reinforce the importance of carefully controlling experimental designs for external factors and of comprehensive, integrative phenotyping strategies. Thus, Nrg1 HETs may, in combination with other genetic and drug models, help to clarify pathophysiological mechanisms behind schizophrenia.

Efficacy of two oral dose regimens of granisetron.

BACKGROUND: Most chemotherapic treatments are carried out on an outpatient basis. In such patients the prevention and control of emesis is important. Granisetron is a specific and extremely potent 5-HT3 antagonist available as an oral formulation. We have carried out an open randomized crossover study in patients receiving moderately emetogenic chemotherapy. MATERIALS AND METHODS: 30 patients were randomized to receive one of the two oral dose regimens of GRAN. Treatment A = 1 mg of GRAN initially and 12 hours after the first; treatment B = a single 2 mg dose of GRAN. RESULTS. An overall good response for vomiting was reached in 70% and 86.7% respectively of patients receiving treatments A and B (p = 0.0625). Good response to nausea was reached in 73.3% of the patients with treatment A and in 76.7% with treatment B (p = 1). 68.3% of patients did not record chemoinduced emesis. CONCLUSION: We believe that oral GRAN alone is an active and safe drug for the prevention of acute chemoinduced emesis.

Defibrotide in the prevention of venous irritation by vinorelbine administration.

BACKGROUND: Vinorelbine is active in a variety of malignancies. The most common side effects are leukopenia and granulocytopenia, moreover Vinorelbine is a vescicant and venous irritant, the incidence of the latter being 10-26% in patients who received VNB as a 20-30 minute peripheral infusion. To prevent venous toxicity we have carried out a study in order to evaluate the efficacy of Defibrotide in this issue. MATERIALS AND METHODS: 41 patients were enrolled in the study, the experimental schedule was: Defibrotide 400 mg on 250 cc of normal saline iv, after 15 minutes of infusion, we delivered quick, brief and repeated pulses of Vinorelbine through the plastic tube followed by remaining Defibrotide: For grading venous irritation we used the scale by Rittenberg et al. RESULTS: A total of 360 infusion were delivered, the incidence of any venous irritation was 5% and maximum grade 2. No severe toxicity was recorded. CONCLUSION: These data show that Defibrotide might serve as a therapeutic drug to prevent vascular toxicity by Vinorelbine.

Bleomycin, epirubicin, carboplatin (BECA) in the treatment of recurrent and/or metastatic squamous cell carcinoma of the head and neck.

The aim of this study was to evaluate three active agents, bleomycin (BLM), epirubicin and carboplatin in a new combination (BECA) in terms of feasibility, activity and toxicity in patients with recurrent and metastatic squamous cell carcinoma of the head and neck. From April 1992 to February 1993 15 pts (12M/3F), median age 53 years, all pretreated (6 surgery + radiotherapy; 3 radiotherapy + chemotherapy; 6 radiotherapy), were treated with BLM 15 mg/m2 days 1-14; epirubicin 30 mg/m2 days 1-14 and carboplatin 300 mg/m2 day 1 every 28 days. In the 14 evaluable pts we observed 1 complete response, CR (7.1%), 4 partial responses, PR (28.6%), 5 stable disease, SD and 4 disease progression, PD with an overall response of 35.7%. The treatment was globally well tolerated, 1 pt with grade 3 leukopenia and 1 pt with grade 3 thrombocytopenia, 1 pt with grade 3 emesis and 1 pt with grade 3 mucositis. At the last follow-up the duration of CR was 34 months, the duration of PRs were respectively 22-10-10-7 months, but the SD ranged from 4 to 6 months. The overall median survival was 8 months (3-36), 14 for responders and 4 for non-responders. This final report seems to confirm the activity and efficacy of the BECA regimen, suitable for outpatient administration with an overall response equal to other more aggressive combinations.

Treatment of advanced and/or metastatic epidermoid carcinoma of the head and neck: an effective combination chemotherapy with bleomycin, methotrexate and ftorafur.

29 evaluable patients with advanced and/or metastatic epidermoid carcinomas of the head and neck were treated with a combination of bleomycin, methotrexate and ftorafur. 3 complete remission, 12 partial remission (objective response 51.7%), 10 stable disease and 4 progressed disease were obtained, with the best responses in the oral cavity and skin carcinomas. The grade of performance status and the pretreatments affected the response, with a very high response rate in nonpretreated patients, where objective results were obtained in all cases. The toxicity was very mild. We believe that this combination can be recommended for epidermoid carcinomas of the skin and oral cavity, considering its high response rate, feasibility and low toxicity.

Ondansetron plus dexamethasone in the control of high dose cisplatin-induced emesis.

Twenty-two patients who underwent chemotherapy with cisplatin (CDDP) at doses > 100 mg/m2 also received antiemetic treatment comprised of the combination of ondansetron plus dexamethasone. The results obtained have shown a good activity from this combination with these high doses of CDDP, with a response of 81.8% (complete+major protection). There were also three therapeutic failures in patients with a few negative prognostic characteristics. It is our intention to use a benzodiazepine and adequate psychological support in an attempt to increase the response percentages in these kinds of patients.

Etoposide, l-leucovorin and fluorouracil (ELF) regimen in metastatic gastric cancer: a phase II study.

The role of chemotherapy in metastatic gastric cancer (MGC) is predominantly palliative, therefore regimens with mild toxicity and acceptable activity should be preferred. The combination of etoposide, leucovorin and 5-fluorouracil (ELF) is suitable chemotherapy in this situation. We have enrolled 33 patients with MGC, using the following chemotherapy schedule: l-leucovorin 150 mg/m2 10 minute i.v., followed by etoposide 120 mg/m2 50 minute i.v., followed by 5-fluorouracil 500 mg/m2 10 minute i.v. on days 1-3, every 22 days. All patients are valuable for response, toxicity and survival. Two patients achieved complete response (6%), 10 patients (30%) had a partial response (PR), 9 patients (27%) had stabilization of disease (SD) and 12 patients had disease progression (PD). The median survival for all patients was 6 months (range, 1 to 40+). ELF was well tolerated, the main toxicity being myelosuppression. No toxic deaths occurred. In conclusion, the ELF regimen in our trial demonstrated, in this kind of patient, moderate activity in the absence of relevant toxicity, confirming its suitability in patients in generally poor condition.

Oral vinorelbine as first line chemotherapy in unfit elderly patients with hormone-refractory prostate cancer.

Hormone-refractory prostate cancer (HRPC) is a rapidly progressive disease which produces considerable morbidity and involves mostly men over 70, often comorbid and with poor tolerance to chemotherapy. Low-toxicity chemotherapy is a reasonable option in this setting. Vinorelbine and a corticosteroid show activity and clinical benefit responses in HRPC. An oral regimen is preferable for elderly patients. This study aimed to evaluate safety, prostate-specific antigen (PSA) response, clinical benefit and progression-free survival in chemonaive elderly HRPC patients. 33 men, median age 78.2, were treated with oral vinorelbine 60 mg/m2 days 1 and 8 every 3 weeks, escalable to 80 mg/m2 after the first cycle, and prednisone 5 mg b.i.d. The main toxicity was hematopoietic (mild at 60 mg/m2 and moderate at 80 mg/m2). Of 27 evaluable patients, 9 (33%) had PSA responses and 9 had clinical benefit, PSA-correlated in 5 cases (56%). Median progression-free survival was 13.4 weeks, median overall survival 45 weeks. Oral vinorelbine plus prednisone is safe and has moderate activity, with biochemical and clinical responses in about one-third of patients and could be an option in unfit elderly HRPC patients.

Overview and new strategies in metastatic breast cancer (MBC) for treatment of tamoxifen-resistant patients.

The treatment with aromatase inhibitors (AIs) and fulvestrant has been demonstrated to be active in a proportion of tamoxifen-resistant breast cancer patients, obtaining, in some cases, a long-term control of tumor growth. Results from clinical trials indicate that treatment with fulvestrant might either precede or follow AIs. However, the AIs are now replacing tamoxifen as first-line advanced and adjuvant therapies, and thus, other options following tamoxifen failure are required. Fulvestrant may be effective in this setting, even if there is also evidence of a lack of cross-resistance between nonsteroidal and steroidal AIs, resulting in the potential use of steroidal AIs following nonsteroidal AI failure and vice versa. Resistance mechanisms to these therapies appear to be related to a cross talk between estrogen receptor (ER) and growth factor-signaling cascades. Novel therapeutic approaches for ER+ patients, which combine hormonal agents and signal transduction inhibitors, have been developed to overcoming resistance. Several trials are now investigating signal transduction inhibitors combined with endocrine agents. This approach might provide efficient treatments and delay the onset of antihormone resistance, thereby significantly improving patient's survival.

Positional cloning, association analysis and expression studies provide convergent evidence that the cadherin gene FAT contains a bipolar disorder susceptibility allele.

A susceptibility locus for bipolar disorder was previously localized to chromosome 4q35 by genetic linkage analysis. We have applied a positional cloning strategy, combined with association analysis and provide evidence that a cadherin gene, FAT, confers susceptibility to bipolar disorder in four independent cohorts (allelic P-values range from 0.003 to 0.024). In two case-control cohorts, association was identified among bipolar cases with a family history of psychiatric illness, whereas in two cohorts of parent-proband trios, association was identified among bipolar cases who had exhibited psychosis. Pooled analysis of the case-control cohort data further supported association (P=0.0002, summary odds ratio=2.31, 95% CI: 1.49-3.59). We localized the bipolar-associated region of the FAT gene to an interval that encodes an intracellular EVH1 domain, a domain that interacts with Ena/VASP proteins, as well as putative beta-catenin binding sites. Expression of Fat, Catnb (beta-catenin), and the three genes (Enah, Evl and Vasp) encoding the Ena/VASP proteins, were investigated in mice following administration of the mood-stabilizing drugs, lithium and valproate. Fat was shown to be significantly downregulated (P=0.027), and Catnb and Enah were significantly upregulated (P=0.0003 and 0.005, respectively), in response to therapeutic doses of lithium. Using a protein interaction map, the expression of genes encoding murine homologs of the FAT (ft)-interacting proteins was investigated. Of 14 interacting molecules that showed expression following microarray analysis (including several members of the Wnt signaling pathway), eight showed significantly altered expression in response to therapeutic doses of lithium (binomial P=0.004). Together, these data provide convergent evidence that FAT and its protein partners may be components of a molecular pathway involved in susceptibility to bipolar disorder.

Phase II study of gemcitabine and cisplatin in patients with advanced or metastatic bladder cancer: long-term follow-up of a 3-week regimen.

BACKGROUND: Bladder cancer is the fifth most common cancer among men and the seventh among women. At diagnosis, at least 25% of bladder cancer tumors are locally or systemically advanced. Systemic chemotherapy is the only current modality for advanced or metastatic transitional cell carcinoma of the bladder. Recently, a phase III randomized study has demonstrated that the regimen with gemcitabine (GMC) and cisplatin (CDDP) had a survival advantage similar to the standard M-VAC (methotrexate, vinblastine, doxorubicin and cisplatin), with a better safety profile. AIM: It was the aim of this study to evaluate the tumor response rate, the median time to progression, the median survival and toxicity in a 21-day schedule with GMC and CDDP in patients with advanced/metastatic bladder cancer. PATIENTS AND METHODS: From September 1998 to December 2000, 27 patients with advanced/metastatic transitional cell carcinoma were enrolled. All patients received 1,200 mg/m(2) GMC administered as a 30-min intravenous infusion on days 1 and 8, and 75 mg/m(2) CDDP as a 1-hour infusion on day 2. Cycles were repeated every 21 days. The patients had a median age of 59.8 years (range 39-75) and an Eastern Cooperative Oncology Group performance status of 0-2. RESULTS: Twenty-five patients were valuable for toxic effects, length of survival and tumor response. The statistical analysis was performed in May 2004. Mean and median follow-up were 20.23 and 13.2 months (range 2-68), respectively. The overall remission rate (complete response + partial response) was 48% (95% CI 28.4-67.6%). The median time to progression was 9 months (range 2-56). The median duration of survival for all patients was 13.2 months (range 2-68+), with 1-year and 23-month survival rates of 60 and 20%, respectively. There was no grade 4 toxicity or treatment-related death. Grade 3 anemia was observed in 4 patients (16%) and grade 3 thrombocytopenia occurred in 6 patients (24%). No grade 3-4 nausea/vomiting or neutropenia was observed. CONCLUSION: GMC and CDDP is an active schedule with a good safety profile in a 21-day regimen. It may be a valid alternative to the standard 28-day regimen due to its high tumor response and survival with a low incidence of toxicity, especially in pretreated and metastatic patients.

Isolation, characterization and antimicrobial activity of coumarin derivatives from Cyperus incompletus.

Ten coumarin derivatives were isolated and characterized by UV, 1H NMR and GC-MS spectra. Their in vitro efficacy against several human pathogenic bacteria and two fungi was evaluated. The tested coumarins showed mild to undefined activity.

Dietary calcium and lead interact to modify maternal blood pressure, erythropoiesis, and fetal and neonatal growth in rats during pregnancy and lactation.

We studied the effects of dietary calcium and lead exposure on lead toxicity, fetal and neonatal growth, erythropoiesis and blood pressure during pregnancy and lactation in rats. Pregnant Sprague-Dawley rats (n = 43) were randomly assigned to one of six treatment groups of 7-8 rats each. Half of the rats were fed diets of low (0.1%), normal (0.5%) or high (2.5%) calcium as calcium carbonate and exposed to 250 mg/L of lead in their drinking water for the duration of the pregnancy and for 1 wk of lactation. Three control groups were fed the same diets without lead exposure. Pups were studied at 1 d and 1 wk of age. Maternal and fetal blood and organ samples from the groups fed the low calcium diet had the highest lead concentrations, whereas the lowest lead concentrations were found in the groups fed the high calcium diet. Dam and pup hemoglobin concentrations, hematocrits, and body weights and lengths were reduced by lead exposure and by the high calcium diet. The latter also reduced organ iron concentrations and prevented lead-induced increases in free erythrocyte protoporphyrin. Dam systolic blood pressures during the third trimester of gestation were significantly higher in rats exposed to lead and fed the low calcium diet than in rats in the other five treatment groups. The results demonstrate that dietary calcium and lead exposure interact in rats to influence maternal blood pressure, erythropoiesis, and fetal and neonatal growth during pregnancy and lactation.

A genome screen of a large bipolar affective disorder pedigree supports evidence for a susceptibility locus on chromosome 13q.

Bipolar affective disorder is a severe mood disorder that afflicts approximately 1% of the population worldwide. Twin and adoption studies have indicated that genetic factors contribute to the disorder and while many chromosomal regions have been implicated, no susceptibility genes have been identified. In this present study, we undertook a 10 cM genome screen using 400 microsatellite markers in a large multigenerational bipolar pedigree consisting of 40 individuals, including six affecteds. We found strongest evidence for linkage to chromosome 13q14. A maximum NPL score of 4.09 (P = 0.008) was obtained between markers D13S1272 and D13S153 using GENEHUNTER. A maximum two-point LOD score of 2.91 (theta = 0.0) was found for marker D13S153 and a maximum three-point LOD score of 3.0 was obtained between markers D13S291 and D13S153 under a recessive model with 90% maximum age-specific penetrance and including bipolar I and unipolar individuals as affected. Several other markers in the region, D13S175, D13S218, D13S263, and D13S156 had two-point LOD scores greater than 1.5. These results meet the criteria for evidence of suggestive linkage. Haplotype analysis enabled us to narrow the likely disease region to a 6 cM region between markers D13S1272 and D13S1319, which contains the serotonin 2A receptor candidate gene. Two single nucleotide polymorphisms were identified in this gene but we did not detect any significant differences in allele frequency in a case-control sample. The region on chromosome 13q14-32 has previously been implicated in other bipolar and schizophrenia cohorts. Our results provide further support for the existence of a susceptibility locus on chromosome 13q14.

A genome screen of 13 bipolar affective disorder pedigrees provides evidence for susceptibility loci on chromosome 3 as well as chromosomes 9, 13 and 19.

Bipolar affective disorder is a severe mood disorder that afflicts approximately 1% of the population worldwide. Twin and adoption studies have indicated that genetic factors contribute to the disorder and while many chromosomal regions have been implicated, no susceptibility genes have been identified. We undertook a combined analysis of 10 cM genome screen data from a single large bipolar affective disorder pedigree, for which we have previously reported linkage to chromosome 13q14 (Badenhop et al, 2001) and 12 pedigrees independently screened using the same 400 microsatellite markers. This 13-pedigree cohort consisted of 231 individuals, including 69 affected members. Two-point LOD score analysis was carried out under heterogeneity for three diagnostic and four genetic models. Non-parametric multipoint analysis was carried out on regions of interest. Two-point heterogeneity LOD scores (HLODs) greater than 1.5 were obtained for 11 markers across the genome, with HLODs greater than 2.0 obtained for four of these markers. The strongest evidence for linkage was at 3q25-26 with a genome-wide maximum score of 2.49 at D3S1279. Six markers across a 50 cM region at 3q25-26 gave HLODs greater than 1.5, with three of these markers producing scores greater than 2.0. Multipoint analysis indicated a 20 cM peak between markers D3S1569 and D3S1614 with a maximum NPL of 2.8 (P= 0.004). Three other chromosomal regions yielded evidence for linkage: 9q31-q33, 13q14 and 19q12-q13. The regions on chromosomes 3q and 13q have previously been implicated in other bipolar and schizophrenia studies. In addition, several individual pedigrees gave LOD scores greater than 1.5 for previously reported bipolar susceptibility loci on chromosomes 18p11, 18q12, 22q11 and 8p22-23.

A transcript map encompassing a susceptibility locus for bipolar affective disorder on chromosome 4q35.

Bipolar affective disorder is one of the most common mental illnesses with a population prevalence of approximately 1%. The disorder is genetically complex, with an increasing number of loci being implicated through genetic linkage studies. However, the specific genetic variations and molecules involved in bipolar susceptibility and pathogenesis are yet to be identified. Genetic linkage analysis has identified a bipolar disorder susceptibility locus on chromosome 4q35, and the interval harbouring this susceptibility gene has been narrowed to a size that is amenable to positional cloning. We have used the resources of the Human Genome Project (HGP) and Celera Genomics to identify overlapping sequenced BAC clones and sequence contigs that represent the region implicated by linkage analysis. A combination of bioinformatic tools and laboratory techniques have been applied to annotate this DNA sequence data and establish a comprehensive transcript map that spans approximately 5.5 Mb. This map encompasses the chromosome 4q35 bipolar susceptibility locus, which localises to a "most probable" candidate interval of approximately 2.3 Mb, within a more conservative candidate interval of approximately 5 Mb. Localised within this map are 11 characterised genes and eight novel genes of unknown function, which together provide a collection of candidate transcripts that may be investigated for association with bipolar disorder. Overall, this region was shown to be very gene-poor, with a high incidence of pseudogenes, and redundant and novel repetitive elements. Our analysis of the interval has demonstrated a significant difference in the extent to which the current HGP and Celera sequence data sets represent this region.

A genome screen of 13 bipolar affective disorder pedigrees provides evidence for susceptibility loci on chromosome 3 as well as chromosomes 9, 13 and 19.

Bipolar affective disorder is a severe mood disorder that afflicts approximately 1% of the population worldwide. Twin and adoption studies have indicated that genetic factors contribute to the disorder and while many chromosomal regions have been implicated, no susceptibility genes have been identified. We undertook a combined analysis of 10 cM genome screen data from a single large bipolar affective disorder pedigree, for which we have previously reported linkage to chromosome 13q14 (Badenhop et al, 2001) and 12 pedigrees independently screened using the same 400 microsatellite markers. This 13 pedigree cohort consisted of 231 individuals, including 69 affected members. Two-point LOD score analysis was carried out under heterogeneity for three diagnostic and four genetic models. Non-parametric multipoint analysis was carried out on regions of interest. Two-point heterogeneity LOD scores (HLODs) greater than 1.5 were obtained for 11 markers across the genome, with HLODs greater than 2.0 obtained for four of these markers. The strongest evidence for linkage was at 3q25-26 with a genome-wide maximum score of 2.49 at D3S1279. Six markers across a 50 cM region at 3q25-26 gave HLODs greater than 1.5, with three of these markers producing scores greater than 2.0. Multipoint analysis indicated a 20 cM peak between markers D3S1569 and D3S1614 with a maximum NPL of 2.8 (P = 0.004). Three other chromosomal regions yielded evidence for linkage: 9q31-q33, 13q14 and 19q12-q13. The regions on chromosomes 3q and 13q have previously been implicated in other bipolar and schizophrenia studies. In addition, several individual pedigrees gave LOD scores greater than 1.5 for previously reported bipolar susceptibility loci on chromosomes 18p11, 18q12, 22q11 and 8p22-23.