Safety and immunogenicity of the two-dose heterologous Ad26.ZEBOV and MVA-BN-Filo Ebola vaccine regimen in infants: a phase 2, randomised, double-blind, active-controlled trial in Guinea and Sierra Leone

BACKGROUND

This study assessed the safety and immunogenicity of the Ad26.ZEBOV and MVA-BN-Filo Ebola virus (EBOV) vaccine regimen in infants aged 4-11 months in Guinea and Sierra Leone.

METHODS

In this phase 2, randomised, double-blind, active-controlled trial, we randomly assigned healthy infants (1:1 in a sentinel cohort, 5:2 for the remaining infants via an interactive web response system) to receive Ad26.ZEBOV followed by MVA-BN-Filo (Ebola vaccine group) or two doses of meningococcal quadrivalent conjugate vaccine (control group) administered 56 days apart. Infants were recruited at two sites in west Africa: Conakry, Guinea, and Kambia, Sierra Leone. All infants received the meningococcal vaccine 8 months after being randomly assigned. The primary objective was safety. The secondary objective was immunogenicity, measured as EBOV glycoprotein-binding antibody concentration 21 days post-dose 2, using the Filovirus Animal Non-Clinical Group ELISA. This study is registered with ClinicalTrials.gov (NCT03929757) and the Pan African Clinical Trials Registry (PACTR201905827924069).

FINDINGS

From Aug 20 to Nov 29, 2019, 142 infants were screened and 108 were randomly assigned (Ebola vaccine n=75; control n=33). The most common solicited local adverse event was injection-site pain (Ebola vaccine 15 [20%] of 75; control four [12%] of 33). The most common solicited systemic adverse events with the Ebola vaccine were irritability (26 [35%] of 75), decreased appetite (18 [24%] of 75), pyrexia (16 [21%] of 75), and decreased activity (15 [20%] of 75). In the control group, ten (30%) of 33 had irritability, seven (21%) of 33 had decreased appetite, three (9%) of 33 had pyrexia, and five (15%) of 33 had decreased activity. The frequency of unsolicited adverse events was 83% (62 of 75 infants) in the Ebola vaccine group and 85% (28 of 33 infants) in the control group. No serious adverse events were vaccine-related. In the Ebola vaccine group, EBOV glycoprotein-binding antibody geometric mean concentrations (GMCs) at 21 days post-dose 2 were 27 700 ELISA units (EU)/mL (95% CI 20 477-37 470) in infants aged 4-8 months and 20 481 EU/mL (15 325-27 372) in infants aged 9-11 months. The responder rate was 100% (74 of 74 responded). In the control group, GMCs for both age groups were less than the lower limit of quantification and the responder rate was 3% (one of 33 responded).

INTERPRETATION

Ad26.ZEBOV and MVA-BN-Filo was well tolerated and induced strong humoral responses in infants younger than 1 year. There were no safety concerns related to vaccination.

FUNDING

Janssen Vaccines & Prevention and Innovative Medicines Initiative 2 Joint Undertaking.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

Safety and immunogenicity of 2-dose heterologous Ad26.ZEBOV, MVA-BN-Filo Ebola vaccination in children and adolescents in Africa: A randomised, placebo-controlled, multicentre Phase II clinical trial

BACKGROUND

Reoccurring Ebola outbreaks in West and Central Africa have led to serious illness and death in thousands of adults and children. The objective of this study was to assess safety, tolerability, and immunogenicity of the heterologous 2-dose Ad26.ZEBOV, MVA-BN-Filo vaccination regimen in adolescents and children in Africa.

METHODS AND FINDINGS

In this multicentre, randomised, observer-blind, placebo-controlled Phase II study, 131 adolescents (12 to 17 years old) and 132 children (4 to 11 years old) were enrolled from Eastern and Western Africa and randomised 5:1 to receive study vaccines or placebo. Vaccine groups received intramuscular injections of Ad26.ZEBOV (5 × 1010 viral particles) and MVA-BN-Filo (1 × 108 infectious units) 28 or 56 days apart; placebo recipients received saline. Primary outcomes were safety and tolerability. Solicited adverse events (AEs) were recorded until 7 days after each vaccination and serious AEs (SAEs) throughout the study. Secondary and exploratory outcomes were humoral immune responses (binding and neutralising Ebola virus [EBOV] glycoprotein [GP]-specific antibodies), up to 1 year after the first dose. Enrolment began on February 26, 2016, and the date of last participant last visit was November 28, 2018. Of the 263 participants enrolled, 217 (109 adolescents, 108 children) received the 2-dose regimen, and 43 (20 adolescents, 23 children) received 2 placebo doses. Median age was 14.0 (range 11 to 17) and 7.0 (range 4 to 11) years for adolescents and children, respectively. Fifty-four percent of the adolescents and 51% of the children were male. All participants were Africans, and, although there was a slight male preponderance overall, the groups were well balanced. No vaccine-related SAEs were reported; solicited AEs were mostly mild/moderate. Twenty-one days post-MVA-BN-Filo vaccination, binding antibody responses against EBOV GP were observed in 100% of vaccinees (106 adolescents, 104 children). Geometric mean concentrations tended to be higher after the 56-day interval (adolescents 13,532 ELISA units [EU]/mL, children 17,388 EU/mL) than the 28-day interval (adolescents 6,993 EU/mL, children 8,007 EU/mL). Humoral responses persisted at least up to Day 365. A limitation of the study is that the follow-up period was limited to 365 days for the majority of the participants, and so it was not possible to determine whether immune responses persisted beyond this time period. Additionally, formal statistical comparisons were not preplanned but were only performed post hoc.

CONCLUSIONS

The heterologous 2-dose vaccination was well tolerated in African adolescents and children with no vaccine-related SAEs. All vaccinees displayed anti-EBOV GP antibodies after the 2-dose regimen, with higher responses in the 56-day interval groups. The frequency of pyrexia after vaccine or placebo was higher in children than in adolescents. These data supported the prophylactic indication against EBOV disease in a paediatric population, as licenced in the EU.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02564523.

Safety and immunogenicity of 2-dose heterologous Ad26.ZEBOV, MVA-BN-Filo Ebola vaccination in healthy and HIV-infected adults: A randomised, placebo-controlled Phase II clinical trial in Africa

BACKGROUND

We investigated safety, tolerability, and immunogenicity of the heterologous 2-dose Ebola vaccination regimen in healthy and HIV-infected adults with different intervals between Ebola vaccinations.

METHODS AND FINDINGS

In this randomised, observer-blind, placebo-controlled Phase II trial, 668 healthy 18- to 70-year-olds and 142 HIV-infected 18- to 50-year-olds were enrolled from 1 site in Kenya and 2 sites each in Burkina Faso, Cote d'Ivoire, and Uganda. Participants received intramuscular Ad26.ZEBOV followed by MVA-BN-Filo at 28-, 56-, or 84-day intervals, or saline. Females represented 31.4% of the healthy adult cohort in contrast to 69.7% of the HIV-infected cohort. A subset of healthy adults received booster vaccination with Ad26.ZEBOV or saline at Day 365. Following vaccinations, adverse events (AEs) were collected until 42 days post last vaccination and serious AEs (SAEs) were recorded from signing of the ICF until the end of the study. The primary endpoint was safety, and the secondary endpoint was immunogenicity. Anti-Ebola virus glycoprotein (EBOV GP) binding and neutralising antibodies were measured at baseline and at predefined time points throughout the study. The first participant was enrolled on 9 November 2015, and the date of last participant's last visit was 12 February 2019. No vaccine-related SAEs and mainly mild-to-moderate AEs were observed among the participants. The most frequent solicited AEs were injection-site pain (local), and fatigue, headache, and myalgia (systemic), respectively. Twenty-one days post-MVA-BN-Filo vaccination, geometric mean concentrations (GMCs) with 95% confidence intervals (CIs) of EBOV GP binding antibodies in healthy adults in 28-, 56-, and 84-day interval groups were 3,085 EU/mL (2,648 to 3,594), 7,518 EU/mL (6,468 to 8,740), and 7,300 EU/mL (5,116 to 10,417), respectively. In HIV-infected adults in 28- and 56-day interval groups, GMCs were 4,207 EU/mL (3,233 to 5,474) and 5,283 EU/mL (4,094 to 6,817), respectively. Antibody responses were observed until Day 365. Ad26.ZEBOV booster vaccination after 1 year induced an anamnestic response. Study limitations include that some healthy adult participants either did not receive dose 2 or received dose 2 outside of their protocol-defined interval and that the follow-up period was limited to 365 days for most participants.

CONCLUSIONS

Ad26.ZEBOV, MVA-BN-Filo vaccination was well tolerated and immunogenic in healthy and HIV-infected African adults. Increasing the interval between vaccinations from 28 to 56 days improved the magnitude of humoral immune responses. Antibody levels persisted to at least 1 year, and Ad26.ZEBOV booster vaccination demonstrated the presence of vaccination-induced immune memory. These data supported the approval by the European Union for prophylaxis against EBOV disease in adults and children ≥1 year of age.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02564523.

Safety and immunogenicity of a two-dose heterologous Ad26.ZEBOV and MVA-BN-Filo Ebola vaccine regimen in adults in Europe (EBOVAC2): a randomised, observer-blind, participant-blind, placebo-controlled, phase 2 trial

BACKGROUND

To address the unmet medical need for an effective prophylactic vaccine against Ebola virus we assessed the safety and immunogenicity of three different two-dose heterologous vaccination regimens with a replication-deficient adenovirus type 26 vector-based vaccine (Ad26.ZEBOV), expressing Zaire Ebola virus glycoprotein, and a non-replicating, recombinant, modified vaccinia Ankara (MVA) vector-based vaccine, encoding glycoproteins from Zaire Ebola virus, Sudan virus, and Marburg virus, and nucleoprotein from the Tai Forest virus.

METHODS

This randomised, observer-blind, placebo-controlled, phase 2 trial was done at seven hospitals in France and two research centres in the UK. Healthy adults (aged 18-65 years) with no history of Ebola vaccination were enrolled into four cohorts. Participants in cohorts I-III were randomly assigned (1:1:1) using computer-generated randomisation codes into three parallel groups (randomisation for cohorts II and III was stratified by country and age), in which participants were to receive an intramuscular injection of Ad26.ZEBOV on day 1, followed by intramuscular injection of MVA-BN-Filo at either 28 days (28-day interval group), 56 days (56-day interval group), or 84 days (84-day interval group) after the first vaccine. Within these three groups, participants in cohort II (14:1) and cohort III (10:3) were further randomly assigned to receive either Ad26.ZEBOV or placebo on day 1, followed by either MVA-BN-Filo or placebo on days 28, 56, or 84. Participants in cohort IV were randomly assigned (5:1) to receive one dose of either Ad26.ZEBOV or placebo on day 1 for vector shedding assessments. For cohorts II and III, study site personnel, sponsor personnel, and participants were masked to vaccine allocation until all participants in these cohorts had completed the post-MVA-BN-Filo vaccination visit at 6 months or had discontinued the trial, whereas cohort I was open-label. For cohort IV, study site personnel and participants were masked to vaccine allocation until all participants in this cohort had completed the post-vaccination visit at 28 days or had discontinued the trial. The primary outcome, analysed in all participants who had received at least one dose of vaccine or placebo (full analysis set), was the safety and tolerability of the three vaccination regimens, as assessed by participant-reported solicited local and systemic adverse events within 7 days of receiving both vaccines, unsolicited adverse events within 42 days of receiving the MVA-BN-Filo vaccine, and serious adverse events over 365 days of follow-up. The secondary outcome was humoral immunogenicity, as measured by the concentration of Ebola virus glycoprotein-binding antibodies at 21 days after receiving the MVA-BN-Filo vaccine. The secondary outcome was assessed in the per-protocol analysis set. This study is registered at ClinicalTrials.gov, NCT02416453, and EudraCT, 2015-000596-27.

FINDINGS

Between June 23, 2015, and April 27, 2016, 423 participants were enrolled: 408 in cohorts I-III were randomly assigned to the 28-day interval group (123 to receive Ad26.ZEBOV and MVA-BN-Filo, and 13 to receive placebo), the 56-day interval group (124 to receive Ad26.ZEBOV and MVA-BN-Filo, and 13 to receive placebo), and the 84-day interval group (117 to receive Ad26.ZEBOV and MVA-BN-Filo, and 18 to receive placebo), and 15 participants in cohort IV were assigned to receive Ad26.ZEBOV and MVA-BN-Filo (n=13) or to receive placebo (n=2). 421 (99·5%) participants received at least one dose of vaccine or placebo. The trial was temporarily suspended after two serious neurological adverse events were reported, one of which was considered as possibly related to vaccination, and per-protocol vaccination was disrupted for some participants. Vaccinations were generally well tolerated. Mild or moderate local adverse events (mostly pain) were reported after 206 (62%) of 332 Ad26.ZEBOV vaccinations, 136 (58%) of 236 MVA-BN-Filo vaccinations, and 11 (15%) of 72 placebo injections. Systemic adverse events were reported after 255 (77%) Ad26.ZEBOV vaccinations, 116 (49%) MVA-BN-Filo vaccinations, and 33 (46%) placebo injections, and included mostly mild or moderate fatigue, headache, or myalgia. Unsolicited adverse events occurred after 115 (35%) of 332 Ad26.ZEBOV vaccinations, 81 (34%) of 236 MVA-BN-Filo vaccinations, and 24 (33%) of 72 placebo injections. At 21 days after receiving the MVA-BN-Filo vaccine, geometric mean concentrations of Ebola virus glycoprotein-binding antibodies were 4627 ELISA units (EU)/mL (95% CI 3649-5867) in the 28-day interval group, 10 131 EU/mL (8554-11 999) in the 56-day interval group, and 11 312 mL (9072-14106) in the 84-day interval group, with antibody concentrations persisting at 1149-1205 EU/mL up to day 365.

INTERPRETATION

The two-dose heterologous regimen with Ad26.ZEBOV and MVA-BN-Filo was safe, well tolerated, and immunogenic, with humoral and cellular immune responses persisting for 1 year after vaccination. Taken together, these data support the intended prophylactic indication for the vaccine regimen.

FUNDING

Innovative Medicines Initiative and Janssen Vaccines & Prevention BV.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

Identification of a chromosome 8p locus for early-onset coronary heart disease in a French Canadian population

Susceptibility to coronary heart disease (CHD) has long been known to exhibit familial aggregation, with heritability estimated to be greater than 50%. The French Canadian population of the Saguenay-Lac Saint-Jean region of Quebec, Canada is descended from a founder population that settled this region 300-400 years ago and this may provide increased power to detect genes contributing to complex traits such as CHD. Probands with early-onset CHD, defined by angiographically determined coronary stenosis, and their relatives were recruited from this population (average sibship size of 6.4). Linkage analysis was performed following a genome-wide microsatellite marker scan on 42 families with 284 individuals. Nonparametric linkage (NPL) analysis provided suggestive evidence for a CHD susceptibility locus on chromosome 8 with an NPL score of 3.14 (P=0.001) at D8S1106. Linkage to this locus was verified by fine mapping in an enlarged sample of 50 families with 320 individuals. This analysis provided evidence of linkage at D8S552 (NPL score=3.53, P=0.0003), a marker that maps to the same location as D8S1106. Candidate genes in this region, including macrophage scavenger receptor 1, farnesyl-diphosphate farnesyltransferase 1, fibrinogen-like 1, and GATA-binding protein 4, were resequenced in all coding exons in both affected and unaffected individuals. Association studies with variants in these and five other genes did not identify a disease-associated mutation. In conclusion, a genome-wide scan and additional fine mapping provide evidence for a locus on chromosome 8 that contributes to CHD in a French Canadian population.

A new form of childhood onset, autosomal recessive spinocerebellar ataxia and epilepsy is localized at 16q21-q23

Childhood ataxias are a complex set of inherited disorders. Ataxias associated with generalized tonic-clonic epilepsy are usually included with the progressive myoclonus epilepsies (PME). Five disease entities, Unverricht-Lundborg disease, Lafora's disease, neuronal ceroid lipofuscinoses, myoclonic epilepsy with ragged red fibres and sialidoses, account for the majority of PME cases. Two rare forms of ataxia plus epilepsy, sensory ataxic neuropathy, dysarthria and ophthalmoparesis, and infantile onset spinocerebellar ataxia were described recently and found to be caused by defective mitochondrial proteins. We report here a large consanguineous family from Saudi Arabia with four affected children presenting with generalized tonic-clonic epilepsy, ataxia and mental retardation, but neither myoclonus nor mental deterioration. MRI and muscle biopsy of one patient revealed, respectively, posterior white matter hyperintensities and vacuolization of the sarcotubular system. We localized the defective gene by homozygosity mapping to a 19 Mb interval in 16q21-q23 between markers D16S3091 and D16S3050. Linkage studies in this region will allow testing for homogeneity of this novel ataxia-epilepsy entity.

Genome-wide scan linkage analysis for Parkinson's disease: the European genetic study of Parkinson's disease

OBJECTIVE

To undertake a full genome-wide screen for Parkinson's disease susceptibility loci.

METHODS

A genome-wide linkage study was undertaken in 227 affected sibling pairs from 199 pedigrees with Parkinson's disease. The pedigree sample consisted of 188 pedigrees from five European countries, and 11 from the USA. Individuals were genotyped for 391 microsatellite markers at approximately 10 cM intervals throughout the genome. Multipoint model-free affected sibling pair linkage analyses were carried out using the MLS (maximum LOD score) test.

RESULTS

There were six chromosomal regions with maximum MLS peaks of 1 or greater (pointwise p<0.018). Four of these chromosomal regions appear to be newly identified regions, and the highest MLS values were obtained on chromosomes 11q (MLS = 1.60, at 91 cM, D11S4175) and 7p (MLS = 1.51, at 5 cM, D7S531). The remaining two MLS peaks, on 2p11-q12 and 5q23, are consistent with excess sharing in regions reported by other studies. The highest MLS peak was observed on chromosome 2p11-q12 (MLS = 2.04, between markers D2S2216 and D2S160), within a relatively short distance (approximately 17 cM) from the PARK3 region. Although a stronger support of linkage to this region was observed in the late age of onset subgroup of families, these differences were not significant. The peak on 5q23 (MLS = 1.05, at 130 cM, D5S471) coincides with the region identified by three other genome scans. All peak locations fell within a 10 cM distance.

CONCLUSIONS

These stratified linkage analyses suggest linkage heterogeneity within the sample across the 2p11-q12 and 5q23 regions, with these two regions contributing independently to Parkinson's disease susceptibility.

Apolipoprotein E4 is probably responsible for the chromosome 19 linkage peak for Parkinson's disease

Analysis of the apolipoprotein E genotype in sibpairs with Parkinson's disease showed the E4 allele was over represented in those who shared the adjacent chromosome 19 markers. This suggests that apolipoprotein E4 is responsible for the linkage peak in this region and that it is a modest risk factor for Parkinson's disease.

Genome screen in the French EGEA study: detection of linked regions shared or not shared by allergic rhinitis and asthma

In the sample of 295 French EGEA families with at least one asthmatic subject, a genome screen was conducted to identify potential linkage regions specific either to allergic rhinitis (AR) or to asthma as well as those shared by the two diseases. Two binary rhinitis phenotypes based on (1) diagnosis (ARbin1) and (2) symptoms (ARbin2) and a categorical ordered trait (ARcat) were considered. Asthma phenotype was based on answers to a standardized questionnaire plus the presence of bronchial hyper-responsiveness. Linkage analyses were conducted using the maximum likelihood binomial (MLB) method. These analyses provided potential evidence for linkage to three regions in the whole sample: 1p31 for the phenotype defined by ARbin2 plus asthma (P=0.00016), 2q32 for ARbin2 (P=0.00016) and 3p24-p14 for ARcat (P=0.001). Two other regions were detected in the subset of 185 families with at most one asthmatic sib: 9p22 and 9q22-q34 for ARbin1 (P=0.001 and 0.0007, respectively). No region showed evidence for linkage to asthma without being also linked to AR. While 1p31 may contain a genetic determinant common to asthma and AR, 2q32, 3p24-p14, 9p22 and 9q22-q34 are more likely to harbor genetic factors specific to AR.

A non-DM1, non-DM2 multisystem myotonic disorder with frontotemporal dementia: phenotype and suggestive mapping of the DM3 locus to chromosome 15q21-24

The majority of proximal myotonic myopathy syndromes reported so far have been related to the myotonic dystrophy (DM) type 2 (DM2) mutation, an expanded (CCTG)n repeat in the ZNF9 gene. Here, we describe the phenotype and the histological features in muscle and brain of the first large pedigree with a non-myotonic dystrophy type 1 (DM1) non-DM2 multisystem myotonic disorder associated with severe frontotemporal dementia. Thirty individuals from three generations underwent detailed neurological, neuropsychological, electrophysiological, brain imaging and molecular analyses. Ten of them had proximal muscle weakness at onset, clinical/electrical myotonia and DM-type cataracts. The mean age at onset was 46.7 +/- 12.6 years (range: 32-69). Dementia was observed later in the course of the disease. On muscle biopsies, rare nuclear clumps, rimmed vacuoles and small angulated type 1 and type 2 fibres were seen early in the disease. They were replaced by fibrous adipose tissue at later stages. Immunohistochemical analysis of myosin heavy chain isoforms showed no selective fibre type atrophy-both type 1 and type 2 fibres being affected. Cortical atrophy without white matter lesions was seen on brain MRI. A brain single photon emission computed tomography (SPECT) study revealed marked frontotemporal hypoperfusion. Post-mortem examination of the brains of two patients showing prominent frontotemporal spongiosis, neuronal loss and rare neuronal and glial tau inclusions suggested frontotemporal dementia. Western blot analyses of the tau protein showed a triplet of isoforms (60, 64 and 69 kDa) in neocortical areas, and a doublet (64 and 69 kDa) in subcortical areas that distinguish our myotonic disorder from other's myotonic dystrophies. Molecular analyses failed to detect a repeat expansion in the DMPK and ZNF9 genes excluding both DM1 and DM2, whereas a genome-wide linkage analysis strongly suggested a linkage to chromosome 15q21-24. This previously unreported multisystem myotonic disorder including findings resembling DM1, DM2 and frontotemporal dementia provides further evidence of the clinical and genetic heterogeneity of the myotonic dystrophies. We propose to designate this disease myotonic dystrophy type 3, DM3.

Homozygosity mapping of Marinesco-Sjögren syndrome to 5q31

Marinesco-Sjögren syndrome (MSS), first described in 1931, is an autosomal recessive condition characterised by somatic and mental retardation, congenital cataracts and cerebellar ataxia. Progressive myopathy was later reported to be also a cardinal sign of MSS, with myopathic changes on muscle biopsies. Hypergonadotrophic hypogonadism and skeletal deformities related to pronounced hypotonia were also reported. The major differential diagnosis of MSS is the syndrome defined by congenital cataracts, facial dysmorphism and peripheral neuropathy (CCFDN), which is localised to 18qter. Using homozygosity mapping strategy in two large consanguineous families of Turkish and Norwegian origin, respectively, we have identified the MSS locus on chromosome 5q31. LOD score calculation, including the consanguinity loops, gave a maximum value of 2.9 and 5.6 at theta=0 for the Turkish and the Norwegian families, respectively, indicating linkage between the disease and the D5S1995-D5S436 haplotype spanning a 9.3 cM interval. Patients of the two families presented with the strict clinical features of MSS. On the other hand, the study of two smaller French and Italian families, initially diagnosed as presenting an atypical MS syndrome, clearly excluded linkage from both the MSS locus on 5q31 and the CCFDN locus in 18qter. Patients of the two excluded families had all MSS features (but the myopathic changes) plus peripheral neuropathy and optic atrophy, and various combinations of microcornea, hearing impairment, seizures, Type I diabetes, cerebral atrophy and leucoencephalopathy, indicating that only the pure MSS syndrome is a homogeneous genetic entity.

Homozygosity mapping of a third Joubert syndrome locus to 6q23

BACKGROUND

Joubert syndrome (JS) is a recessively inherited disorder characterised by hypotonia at birth and developmental delay, followed by truncal ataxia and cognitive impairment, characteristic neuroimaging findings (cerebellar vermis hypoplasia, "molar tooth sign") and suggestive facial features. JS is clinically heterogeneous with some patients presenting with breathing abnormalities in the neonatal period, oculomotor apraxia, retinal dystrophy, retinal coloboma, ptosis, hexadactyly, and nephronophtisis or cystic dysplastic kidneys. JS is also genetically heterogeneous, with two known loci, on 9q34 (JBTS1) and 11p11-q12 (CORS2), representing only a fraction of cases.

METHODS

A large consanguineous Joubert family (five affected) was analysed for linkage with a marker set covering the entire genome and 16 smaller families were subsequently tested for candidate loci.

RESULTS

We report here the identification of a third locus in 6q23 (JBTS3) from the study of two consanguineous families. LOD score calculation, including the consanguinity loops, gave a maximum value of 4.1 and 2.3 at q = 0 for the two families, respectively.

CONCLUSIONS

Linkage between the disease and the D6S1620-D6S1699 haplotype spanning a 13.1 cM interval is demonstrated. Genotype-phenotype studies indicate that, unlike CORS2, JBTS3 appears not to be associated with renal dysfunction.

Mapping susceptibility genes for bipolar disorder: a pharmacogenetic approach based on excellent response to lithium

Genetic mapping studies in bipolar disorder (BD) have been hampered by the unclear boundaries of the phenotypic spectrum, and possibly, by the complexity of the underlying genetic mechanisms, and heterogeneity. Among the suggested approaches to circumvent these problems, a pharmacogenetic strategy has been increasingly proposed. Several studies have indicated that patients with BD who respond well to lithium prophylaxis constitute a biologically distinct subgroup. In this study we have conducted a complete genome scan using 378 markers spaced at an average distance of 10 cM in 31 families ascertained through excellent lithium responders. Response to lithium was evaluated prospectively with an average follow-up of 12 years. Evidence for linkage was found with a locus on chromosome 15q14 (ACTC, lod score = 3.46, locus-specific P-value = 0.000014) and suggestive results were observed for another marker on chromosome 7q11.2 (D7S1816, lod score = 2.68, locus-specific P-value = 0.00011). Other interesting findings were obtained with markers on chromosomes 6 and 22, namely D6S1050 (lod score = 2.0, locus-specific P-value = 0.00004) and D22S420 (lod score = 1.91). Nonparametric linkage analysis provided additional support for the role of these loci. Further analyses of these results suggested that the locus on chromosome 15q14 may be implicated in the etiology of BD, whereas the 7q11.2 locus may be relevant for lithium response. In conclusion, our results provide original evidence suggesting that loci on 15q14 and 7q11.2 may be implicated in the pathogenesis of BD responsive to lithium.

Shwachman-Diamond syndrome with exocrine pancreatic dysfunction and bone marrow failure maps to the centromeric region of chromosome 7

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by exocrine pancreatic insufficiency and hematologic and skeletal abnormalities. A genomewide scan of families with SDS was terminated at approximately 50% completion, with the identification of chromosome 7 markers that showed linkage with the disease. Finer mapping revealed significant linkage across a broad interval that included the centromere. The maximum two-point LOD score was 8.7, with D7S473, at a recombination fraction of 0. The maximum multipoint LOD score was 10, in the interval between D7S499 and D7S482 (5.4 cM on the female map and 0 cM on the male map), a region delimited by recombinant events detected in affected children. Evidence from all 15 of the multiplex families analyzed provided support for the linkage, consistent with a single locus for SDS. However, the presence of several different mutations is suggested by the heterogeneity of disease-associated haplotypes in the candidate region.

Localization of a recessive gene for North American Indian childhood cirrhosis to chromosome region 16q22-and identification of a shared haplotype

North American Indian childhood cirrhosis (NAIC, or CIRH1A) is an isolated nonsyndromic form of familial cholestasis reported in Ojibway-Cree children and young adults in northwestern Quebec. The pattern of transmission is consistent with an autosomal recessive mode of inheritance. To map the NAIC locus, we performed a genomewide scan on three DNA pools of samples from 13 patients, 16 unaffected siblings, and 22 parents from five families. Analysis of 333 highly polymorphic markers revealed 3 markers with apparent excess allele sharing among affected individuals. Additional mapping identified a chromosome 16q segment shared by all affected individuals. When the program FASTLINK/LINKAGE was used and a completely penetrant autosomal recessive mode of inheritance was assumed, a maximum LOD score of 4.44 was observed for a recombination fraction of 0, with marker D16S3067. A five-marker haplotype (D16S3067, D16S752, D16S2624, D16S3025, and D16S3106) spanning 4.9 cM was shared by all patients. These results provide significant evidence of linkage for a candidate gene on chromosome 16q22.

Molecular scanning of the human PPARa gene: association of the L162v mutation with hyperapobetalipoproteinemia

Peroxisome proliferator-activated receptor alpha (PPARalpha) is a member of the steroid hormone receptor super family involved in the control of cellular lipid utilization. This makes PPARalpha a candidate gene for type 2 diabetes and dyslipidemia. The aim of this study was to investigate whether genetic variation in the human PPARalpha gene can influence the risk of type 2 diabetes and dyslipidemia among French Canadians. We therefore first determined the genomic structure of human PPARalpha, and then designed intronic primers to sequence the coding region and the exon-intron boundaries of the gene in 12 patients with type 2 diabetes and in 2 nondiabetic subjects. Sequence analysis revealed the presence of a L162V missense mutation in exon 5 of one diabetic patient. Leucine 162 is contained within the DNA binding domain of the human PPARalpha gene, and is conserved among humans, mice, rats, and guinea pigs. We subsequently screened a sample of 121 patients newly diagnosed with type 2 diabetes and their age and sex-matched nondiabetic controls, recruited from the Saguenay-Lac-St-Jean region of Northeastern Quebec, for the presence of the L162V mutation by a PCR-RFLP based method. There was no difference in L162 homozygote or V162 carrier frequencies between diabetics and nondiabetics. However, whether diabetic or not, carriers of the V162 allele had higher plasma apolipoprotein B levels compared to noncarriers (P 5 0.05). To further this association, we screened another sample of 193 nondiabetic subjects recruited in the greater Quebec City area. Carriers of the V162 allele compared with homozygotes of the L162 allele had significantly higher concentrations of plasma total and LDL-apolipoprotein B as well as LDL cholesterol (P </= 0.02). These results suggest an association between the PPARalpha V162 allele and the atherogenic/hyperapolipoprotein B dyslipidemia.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS): high-resolution physical and transcript map of the candidate region in chromosome region 13q11

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS or SACS) is a neurodegenerative disease frequent in northeastern Québec. In a previous study, we localized the disease gene to chromosome region 13q11 by identifying excess sharing of a marker allele in patients followed by linkage analysis and haplotyping. To create a detailed physical map of this region, we screened CEPH mega-YACs with 41 chromosome 13 sequence-tagged-sites (STSs) known to map to 13q11-q12. The YAC contig, composed of 27 clones, extends on the genetic map from D13S175 to D13S221, an estimated distance of at least 19.3 cM. A high-resolution BAC and PAC map that includes the ARSACS critical region flanked by D13S1275 and D13S292 was constructed. These YAC and BAC/PAC maps allowed the accurate placement of 29 genes and ESTs previously mapped to the proximal region of chromosome 13q. We confirmed the position of two candidate genes within the critical region and mapped the other 27 genes and ESTs to nearby intervals. Six BAC/PAC clones form a contig between D13S232 and D13S787 for sequencing within the ARSACS critical region.

Influence of genetic variability in the nondeletion LDL-receptor allele on phenotypic variation in French-Canadian familial hypercholesterolemia heterozygotes sharing a 'null' LDL-receptor gene defect

We investigated the associations between low density lipoprotein (LDL)-receptor gene haplotypes and lipid and lipoprotein levels in French-Canadian individuals with familial hypercholesterolemia (FH). The 112 unrelated patients studied shared the same > 10 Kb deletion in the 5' region of the LDL-receptor gene, leading to a null allele. Support for the hypothesis that the deletion is carried on only one LDL-receptor restriction fragment length polymorphism (RFLP) haplotype in this sample has previously been demonstrated [1]. We studied associations of genetic variability in DNA polymorphisms of the nondeletion LDL-receptor allele with variation in plasma lipid levels in these patients heterozygous for the deletion. All analyses were done separately in males and females. The traits were adjusted for variation in the concomitants age, height and weight, and for variation in apolipoprotein (apo) E phenotype, and then the association between variability in haplotypes defined by two RFLP loci and variation in trait levels were tested. The results indicated that in this sample of French-Canadian > 10 Kb deletion FH heterozygotes, variability at the LDL-receptor gene contributes to quantitative variation in measures of lipid metabolism and that the effects are different in males and females. The results indicated that variability at the LDL-receptor gene defined by two RFLP loci contributes to quantitative variation in high density lipoprotein (HDL)-cholesterol and LDL-cholesterol concentrations in French-Canadian FH women heterozygous for the > 10 Kb deletion and not in men.

Distribution of brain cytochrome oxidase activity in various neurodegenerative diseases

Cytochrome oxidase (CO) is the terminal complex of the mitochondrial respiratory chain which generates ATP by oxidative phosphorylation. We have measured CO activity in six different brain regions of patients with senile dementia of Alzheimer type (SDAT, n = 10), presenile dementia of Alzheimer type (PDAT, n = 10), Lewy body dementia with SDAT (LBD, n = 5), cerebrovascular dementia (CVD, n = 10), Parkinson dementia (PD, n = 5), and in controls (n = 8), as all confirmed by neuropathological evaluation. CO activity was lower in the frontal and parietal cortex of SDAT patients compared to controls. Patients with PDAT, LBD, CVD or PD showed no significant reduction of the enzymatic activity in the six regions studied. Our results show that reduced CO activity might play a role in the physiopathology of senile dementia of Alzheimer type.

Apo E allele frequencies in Alzheimer's disease, Lewy body dementia, Alzheimer's disease with cerebrovascular disease and vascular dementia

Apolipoprotein (Apo E) was genotyped using a fluorescent PCR-RFLP assay in 187 patients with a probable or possible clinical diagnosis of sporadic Alzheimer's disease (AD) and in 166 autopsied patients with dementia (21 presenile AD, 70 senile AD, 18 Lewy body dementia (LBD), 38 AD with cerebrovascular disease (AD-CVD), 19 vascular dementia). The relative epsilon 4 allele frequency was 0.472 in LBD, 0.513 in AD-CVD, 0.405 in presenile AD, 0.364 in senile AD, and 0.079 in vascular dementia. The relative epsilon 2 allele frequency was 0.211 in vascular dementia, 0.083 in LBD, 0.047 in presenile AD, 0.100 in senile AD and 0.039 in AD with CVD. We infer that apo E is a major risk factor for structural phenotypes of dementia involving AD, alone or in conjunction with another pathology. In addition, the epsilon 2 allele is likely to represent a risk factor for vascular morbidity, as the relative epsilon 2 allele frequency was 0.211 in patients with vascular dementia compared with 0.144 in elderly controls.

Mutations of low-density-lipoprotein-receptor gene, variation in plasma cholesterol, and expression of coronary heart disease in homozygous familial hypercholesterolaemia

Variation in plasma-cholesterol concentration and the expression of coronary heart disease in patients with homozygous familial hypercholesterolaemia (FH) is well documented, but the underlying reasons for variation are not clearly defined. Because FH is caused by mutations at the low-density-lipoprotein-gene locus, we compared plasma-cholesterol concentrations in 21 FH homozygotes with either the greater than 10 kb deletion (promoter region and exon 1) (11 subjects) or the exon 3 missense (trp66-->gly) mutation (10 subjects) of the low-density-lipoprotein gene. Subjects with the greater than 10 kb deletion had a higher mean plasma-cholesterol concentration than those with the exon 3 mutations (26.7 vs 16.1 mmol/L; p = 0.000006), and there was no overlap in individual plasma-cholesterol concentrations between subjects in the two groups. Although the frequency of coronary heart disease was similar in the two groups, age-of-onset was earlier in subjects with the greater than 10 kb deletion (p = 0.059). Also, coronary deaths were more frequent (p = 0.044) and occurred at an earlier age (p = 0.009) in subjects with the greater than 10 kb deletion. Our results provide evidence that there is less variation in plasma-cholesterol concentrations among FH homozygotes when they are subdivided into groups according to low-density-lipoprotein-receptor-gene defect. Furthermore, differences in plasma-cholesterol concentrations are reflected in the severity of coronary heart disease expression.

Phenotypic heterogeneity associated with defective apolipoprotein B-100 and occurrence of the familial hypercholesterolemia phenotype in the absence of an LDL-receptor defect within a Canadian kindred

Of 163 individuals with a diagnosis of heterozygous familial hypercholesterolemia (FH), only one subject was found to be positive for familial defective apo B-100 (FDB). The eight-member kindred ascertained through this subject who presented with both a clinical phenotype of FH and the FDB apo B-100 (Arg3500----Gln) mutation was studied. Plasma lipid and lipoprotein profiles, apo E phenotypes, apo B gene markers at the 3' hypervariable region and LDL-receptor haplotypes (ApaLI, PvuII, NcoI), were determined, together with LDL-receptor activity on freshly isolated blood lymphocytes. The FDB mutation, present in four relatives, was associated with three different phenotypes: FH and severe hypercholesterolemia, moderate hypercholesterolemia and normolipidemia. The FH phenotype occurred in the absence of any functional LDL-receptor defect. In homozygotes for the absence of the PvuII cutting site who had the apo B mutation, LDL-cholesterol levels were low in the presence of the apo E3/2 phenotype and high in the presence of the apo E4/4 phenotype. None of the major known environmental influences accounted for the wide range of variation in LDL-cholesterol among the affected members. Further observations in the spouse and offspring of the normolipidemic FDB subject confirmed the association of apo E4, the FDB mutation and the PvuII(-/-) genotype with high cholesterol levels. It is concluded that the phenotypic expression of the FDB mutation may vary widely as a function of the genetic environment within a family.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular genetic evidence for a founder effect in familial hypercholesterolemia among French Canadians

Familial hypercholesterolemia (FH), at a prevalence of about 1 in 200 in the French-Canadian population, is caused by a 10-kb deletion in the low-density lipoprotein (LDL) receptor gene in 60% of French-Canadian FH heterozygotes. We genotyped 159 FH patients who carry this common mutation and 221 healthy French-Canadian controls for five DNA restriction fragment length polymorphisms (RFLPs) of the LDL receptor gene. The allele numbers for four of the five RFLPs differed significantly (P less than 0.001) between FH patients and control subjects. Our results suggest that the 10-kb deletion carrier allele is associated with a single haplotype (called the B haplotype). In a family study including a patient homozygous for the 10-kb deletion, we showed that the B haplotype cosegregates with the deletion in affected members and that the B haplotype is also associated with the normal allele in some members of the family. We identified 15 different haplotypes for the normal allele in 10-kb deletion carrier FH heterozygotes. These results offer strong support, at a molecular level, for the hypothesis of a founder effect for the 10-kb deletion in the French-Canadian population.

Patterns of association between genetic variability in apolipoprotein (apo) B, apo AI-CIII-AIV, and cholesterol ester transfer protein gene regions and quantitative variation in lipid and lipoprotein traits: influence of gender and exogenous hormones

Patterns of RFLP association were studied, to identify gene regions influencing quantitative variation in lipid and lipoprotein traits (coronary artery disease [CAD] risk factors or metabolically related traits). Subjects (118 female and 229 male; age 20-59 years) were selected for health. Multiple RFLPs were used to sample variability in regions around genes for apolipoprotein (apo) B (restriction enzymes HincII, PvuII, EcoRI, and XbaI), apo AI-CIII-AIV (BamHI, XmnI, TaqI, PstI, SstI, and PvuII) and cholesterol ester transfer protein (TaqI). Separate analyses were done by gender. The sample was truncated at mean +/- 4 SD, to remove extreme outliers. There was no significant gender difference in RFLP genotype frequency distribution. After trait-level adjustment to maximize removal of concomitant variability, analysis of variance was used to estimate the percentage trait phenotypic variance explained by measured variability in the gene regions studied. Fewer gene regions were involved in men, with less influence on quantitative trait variation than in women, in whom hormone use affected association patterns. Gender differences imply that pooling genders or adjusting data for gender effects removes genetic information and should be avoided. The association patterns show that variability around the candidate genes modulates trait levels: the genes are contributors to the genetics of CAD risk variables in a healthy sample.

Identification of a second "French Canadian" LDL receptor gene deletion and development of a rapid method to detect both deletions

Hobbs et al. (N. Engl. J. Med. 317: 734-737, 1987) reported a large deletion of approximately 10 kilobases in the 5' portion of the human low-density lipoprotein (LDL) receptor gene. This deletion affects about 60% of familial hypercholesterolemia (FH) heterozygotes in the French Canadian population. We have developed a rapid, convenient method for the detection of the deletion using double digestion with the restriction enzymes XbaI and EcoRV, or triple digestion with XbaI, EcoRV and XmnI, and a 650 bp cDNA probe, radio-labeled using a random oligonucleotide primer technique. Eighty French Canadian FH heterozygotes were screened for the presence of the deletion. Forty-seven (59%) of them were found to carry the 10 kb deletion. Using the same method, we also identified a new mutation which was found in four of the 80 (5%) FH patients. This mutation has been found to be a 5 kb deletion removing exons 2 and 3 of the LDL receptor gene, which correspond to the first two repeats of the LDL receptor binding domain. Cosegregation of the 5 kb deletion and the FH phenotype was observed in one family. Possible structure-function relationship is discussed.