The Canadian Collaborative Project on Genetic Susceptibility to Multiple Sclerosis cohort population structure and disease etiology.

Background: Previous genetic and epidemiological studies have examined subpopulations from the Canadian Collaborative Project on Genetic Susceptibility to Multiple Sclerosis (CCPGSMS) patient cohort, but an encompassing analysis of the study population has not yet been carried out.

Objective: This study examines patterns of multiple sclerosis (MS) prevalence in 13,663 cohort members, including 4,821 patients with MS or suspected MS and 8,842 family members.

Methods: We grouped participants into epidemiologic subgroups based on age of MS onset, clinical stage at diagnosis, symptom type at disease onset, sex, proband status, disability as measured by the EDSS, and ancestry based on reported ethnicity.

The Canadian Multiple Sclerosis Pregnancy Study: First-trimester miscarriages in women with multiple sclerosis.

Background: There is increasing need for evidence-based data on reproduction for women with multiple sclerosis (MS). First-trimester (first 13 weeks) miscarriages are relatively common in the general population. It is therefore important to have information on the frequency with which this occurs in women with MS.

A Whole-Genome Sequencing Study Implicates GRAMD1B in Multiple Sclerosis Susceptibility.

While the role of common genetic variants in multiple sclerosis (MS) has been elucidated in large genome-wide association studies, the contribution of rare variants to the disease remains unclear. Herein, a whole-genome sequencing study in four affected and four healthy relatives of a consanguineous Italian family identified a novel missense c.1801T > C (p.

Peripartum disease activity in moderately and severely disabled women with multiple sclerosis.

Background: The effects of pregnancy on multiple sclerosis (MS) inflammatory activity are not well described in women with moderate to severe disabilities.

Objective: To quantify the peripartum annualized relapse rate (ARR) in women with MS with an Expanded Disability Status Scale (EDSS) ≥ 3.

Methods: We performed a retrospective cohort study of 85 pregnancies in 74 subjects with preconception EDSS ≥ 3.

Cortical morphology predicts placebo response in multiple sclerosis.

Despite significant insights into the neural mechanisms of acute placebo responses, less is known about longer-term placebo responses, such as those seen in clinical trials, or their interactions with brain disease. We examined brain correlates of placebo responses in a randomized trial of a then controversial and now disproved endovascular treatment for multiple sclerosis. Patients received either balloon or sham extracranial venoplasty and were followed for 48 weeks.

Risk factors for peripartum depression in women with multiple sclerosis.

Background: Peripartum depression (PPD) is underexplored in multiple sclerosis (MS).

Objective: To evaluate prevalence of and risk factors for PPD in women with MS.

Methods: Retrospective single-center analysis of women with MS with a live birth.

The road to conception for women with multiple sclerosis.

Objective: The objective of this prospective "real world" study is to gain insight into the different "roads to conception" that women with MS take as part of the prospective Canadian Multiple Sclerosis Pregnancy Study (CANPREG-MS).

Methods: Participants are women with MS who are planning a pregnancy. Data cut-off for analyses was April 30, 2020.

Genes and environment in multiple sclerosis: Impact of temporal changes in the sex ratio on recurrence risks.

Objective: To evaluate the impact of temporal increase of female to male (F:M) sex ratio for persons with multiple sclerosis (MS) on the familial risk (empiric recurrence risks or RRs) for biological relatives of affected individuals.

Methods: Detailed family histories were systematically obtained from people with MS attending the University of British Columbia Hospital MS Clinic. The study cohort was born in 1970 or more recently.

Genetic analysis of nucleotide-binding leucine-rich repeat (NLR) receptors in multiple sclerosis.

Genetic and functional analyses of the inflammasome suggest a role for this multiprotein complex in the biological mechanisms leading to the onset and progression of multiple sclerosis (MS). Nucleotide-binding, leucine-rich repeat (NLR) receptors trigger the activation and assembly of specific inflammasomes in response to danger signals. Mining exome sequencing data from 326 MS patients identified 17 rare missense or nonsense variants in NLR family pyrin domain containing 1 (NLRP1), NLRP3, NLRP6, NLRP7 and NLR family CARD domain containing 4 (NLRC4).

Canadian Multiple Sclerosis Pregnancy Study (CANPREG-MS): Rationale and Methodology.

Background: Multiple sclerosis (MS) is the most common cause of neurological disability, other than trauma, among young adults of reproductive age. In contrast to the past, today there is very little lag time from clinical onset to diagnosis. Disease-modifying therapies are also now available outside of clinical trials.

NLRX1 inhibits the early stages of CNS inflammation and prevents the onset of spontaneous autoimmunity.

Nucleotide-binding, leucine-rich repeat containing X1 (NLRX1) is a mitochondria-located innate immune sensor that inhibits major pro-inflammatory pathways such as type I interferon and nuclear factor-κB signaling. We generated a novel, spontaneous, and rapidly progressing mouse model of multiple sclerosis (MS) by crossing myelin-specific T-cell receptor (TCR) transgenic mice with Nlrx1-/- mice. About half of the resulting progeny developed spontaneous experimental autoimmune encephalomyelitis (spEAE), which was associated with severe demyelination and inflammation in the central nervous system (CNS).

Abnormal effector and regulatory T cell subsets in paediatric-onset multiple sclerosis.

Elucidation of distinct T-cell subsets involved in multiple sclerosis immune-pathophysiology continues to be of considerable interest since an ultimate goal is to more selectively target the aberrant immune response operating in individual patients. While abnormalities of both effector (Teff) and regulatory (Treg) T cells have been reported in patients with multiple sclerosis, prior studies have mostly assessed average abnormalities in either limb of the immune response, rather than both at the same time, which limits the ability to evaluate the balance between effectors and regulators operating in the same patient. Assessing both phenotypic and functional responses of Teffs and Tregs has also proven important.

TPP2 mutation associated with sterile brain inflammation mimicking MS.

Objective: To ascertain the genetic cause of a consanguineous family from Syria suffering from a sterile brain inflammation mimicking a mild nonprogressive form of MS.

Methods: We used homozygosity mapping and next-generation sequencing to detect the disease-causing gene in the affected siblings. In addition, we performed RNA and protein expression studies, enzymatic activity assays, immunohistochemistry, and targeted sequencing of further MS cases from Austria, Germany, Canada and Jordan.

Increased mean R2* in the deep gray matter of multiple sclerosis patients: Have we been measuring atrophy?

Background: Magnetic resonance relaxometry studies in multiple sclerosis (MS) have suggested that iron accumulates within deep gray matter (DGM) structures early in the disease course. However, the commonly utilized mean R2* and magnetic susceptibility measures reflect regional iron concentration but not a structure's total iron content. Thus, tissue atrophy could impact mean R2* and magnetic susceptibility estimates.

Safety and efficacy of venoplasty in MS: A randomized, double-blind, sham-controlled phase II trial.

Objective: To determine the safety and efficacy of balloon vs sham venoplasty of narrowing of the extracranial jugular and azygos veins in multiple sclerosis (MS).

Methods: Patients with relapsing or progressive MS were screened using clinical and ultrasound criteria. After confirmation of >50% narrowing by venography, participants were randomized 1:1 to receive balloon or sham venoplasty of all stenoses and were followed for 48 weeks.

Exome sequencing study in patients with multiple sclerosis reveals variants associated with disease course.

Background: It remains unclear whether disease course in multiple sclerosis (MS) is influenced by genetic polymorphisms. Here, we aimed to identify genetic variants associated with benign and aggressive disease courses in MS patients.

Methods: MS patients were classified into benign and aggressive phenotypes according to clinical criteria.

Analysis of NOD-like receptor NLRP1 in multiple sclerosis families.

The implementation of exome sequencing technologies has started to unravel the genetic etiology of familial multiple sclerosis (MS). A homozygote p.G587S mutation in NLRP1 has been suggested as potentially causative for the onset of MS in an affected sibling pair, who later developed malignant melanoma.

Multiple sclerosis in First Nations Canadians: A pilot comparison study.

Background: Genetic and clinical characteristics associated with multiple sclerosis (MS) may differ by ethnicity but few studies have evaluated whether characteristics of MS differ between individuals according to First Nations (FN) ethnicity.

Objective: Using a cross-sectional observational design, we compared clinical and genetic characteristics between people with MS of FN and non-FN ethnicity.

Methods: We recruited participants of FN ethnicity with MS.

Genetic modifiers of multiple sclerosis progression, severity and onset.

The genetic contribution to clinical outcomes for multiple sclerosis (MS) has yet to be defined. We performed exome sequencing analysis in 100 MS patients presenting opposite extremes of clinical phenotype (discovery cohort), and genotyped variants of interest in 2016 MS patients (replication cohort). Linear and logistic regression analyses were used to identify significant associations with disease course, severity and onset.

Common genetic etiology between "multiple sclerosis-like" single-gene disorders and familial multiple sclerosis.

Several single-gene disorders with clinical and radiological characteristics similar to those observed in multiple sclerosis (MS) patients have been described. To evaluate whether this phenotypic overlap can be ascribed to a common genetic etiology, 28 genes known to present pathogenic mutations for 24 of these disorders were sequenced in 270 MS patients. All identified variants were genotyped in 2131 MS cases and 830 healthy controls, and those exclusively observed in patients were assessed for segregation within families.

Purinergic receptors P2RX4 and P2RX7 in familial multiple sclerosis.

Genetic variants in the purinergic receptors P2RX4 and P2RX7 have been shown to affect susceptibility to multiple sclerosis (MS). In this study, we set out to evaluate whether rare coding variants of major effect could also be identified in these purinergic receptors. Sequencing analysis of P2RX4 and P2RX7 in 193 MS patients and 100 controls led to the identification of a rare three variant haplotype (P2RX7 rs140915863:C>T [p.