Distribution of disease courses in familial vs sporadic multiple sclerosis

Exome sequencing reveals low-frequency and rare variant contributions to multiple sclerosis susceptibility in Turkish families

Multiple sclerosis (MS) is characterized as an immune-mediated central nervous system disease marked by chronic inflammation, demyelination, and progressive neurodegeneration. In this study, we evaluated the contribution of low-frequency and rare genetic variants to MS susceptibility within one of the largest family-based MS cohorts to date, comprising 215 individuals from 59 Turkish multiplex MS families. Whole exome sequencing was conducted on all samples including affected and unaffected members, followed by investigation of the effect of well-established human leukocyte antigen loci for MS on the elevated MS risk observed in our families. Subsequently, a gene-based burden analysis was performed on candidate genes identified through both our segregation analysis and existing literature. To prioritize the genes and pathways that are potentially associated with MS, a segregation-based analysis of the variants was conducted and complemented by gene-based pathway enrichment analysis. Our results highlighted the significance of the extracellular matrix in MS pathogenesis, as we identified laminin-related genes including LAMA5 and LAMB1 from both the segregation analysis and gene-based burden test. Hemidesmosome assembly emerged as a key pathway in our analysis, primarily driven by the identification of DST and PLEC as significant genes in the gene-based segregation analysis. Finally, we identified two rare coding variants passing our allele frequency and deleteriousness score-based filters, rs41266745 (C> T) in the CD109 gene with CADD phred score 24 and rs143093165 (T> G) in the ITPR1 gene with CADD phred score 22 and LOEUF 0.325, segregating within more than one family. Overall, this is one of the first and largest family-based MS studies from Turkey that features a unique cohort from an admixed population that enabled the detection of novel low-frequency and rare variants associated with MS. The findings from this study offer valuable insights that could guide future research aimed at further exploring and understanding the factors contributing to MS risk.

The role of parental consanguinity and familial aggregation in development of multiple sclerosis: a case-control study

BACKGROUND

Several studies pointed out the importance of genetic risk factors such as parental consanguinity (PC) and familial multiple sclerosis (FMS) in the risk of MS. This study aimed to investigate the PC and FMS among people with MS (pwMS) in Isfahan, Iran.

METHODS

This case-control study was conducted on pwMS from the MS clinic of Kashani Hospital, Isfahan, Iran, in October 2023. A group of healthy controls (HC) were also recruited. Data on demographic and clinical characteristics and history of PC and FMS were collected from participants. The relationships between PC, FMS, and developing MS were assessed using multinomial logistic regression analysis. The odds ratio (OR) with a 95% confidence interval (CI) was computed.

RESULTS

A total number of 4264 pwMS and 400 HCs were included. The prevalence of PC and FMS among pwMS were 29.3% and 24%, respectively. Multinomial logistic regression adjusted for age and sex indicated that the odds of developing MS were significantly associated with a history of PC (OR = 3.03, 95% CI 2.23 to 4.13, p < 0.001) and FMS (OR = 5.42, 95% CI 3.51 to 8.38, p < 0.001).

CONCLUSION

PC and FMS can increase the risk of developing MS. They should be considered along with other risk factors for developing MS. A comprehensive conclusion requires further research.

Earlier age of symptom onset in younger generation of familial cases of multiple sclerosis

AIM

The aim of this study was to assess the prevalence of familial MS (fMS) in Belgrade MS population, discern the differences between the persons with fMS and sporadic MS, and to detect the presence of anticipation phenomenon in fMS patients.

METHODS

The data on the demographic and clinical characteristics of MS patients was obtained from the Belgrade MS population Registry. In cases of vertical transmission of MS, the family members were divided into the younger and older generation, in order to assess the potential presence of anticipation phenomenon. To adjust for follow-up time bias, a secondary analysis including only patients who had the onset of symptoms before 39 years (75.percentile), and those who were 39 + years, was performed.

RESULTS

The prevalence of fMS in Belgrade MS population is 6.4%. FMS cases had earlier age at MS symptom onset (30.4 vs. 32.3 years) compared to sporadic MS cohort. When comparing fMS cases across generations, the younger generation had significantly lower age at onset compared with the older one (25.8 vs. 35.7 years, p < 0.001). After adjustment for the different length of the follow-up, the difference in age at symptom onset between the groups was reduced, but it still existed and was statistically significant (30.0 years in younger vs. 36.4 years in older generation, p = 0.040).

CONCLUSION

In our study, the analysis of fMS cases across generations, showed an earlier age of symptom onset in the younger generation, even after adjustment. These results indicate the possibility of existence of anticipation phenomenon.

Comparing Clinical and Radiological Features in Familial and Sporadic Multiple Sclerosis

Objective To compare the initial presentation, clinical features, disease courses, and radiological parameters between familial multiple sclerosis (fMS) and sporadic multiple sclerosis (sMS) to determine if the two represent distinct clinical entities. Methods This retrospective study was conducted at the Neurology Clinic at Kocaeli University Hospital. Records of 114 fMS and 150 sMS patients, aged 18-65, diagnosed based on either the Poser criteria or the McDonald 2001 criteria were analyzed. Radiological data and Expanded Disability Status Scale (EDSS) evaluations were conducted by a specialist neurologist. Variables included age at MS onset, first symptoms, relapses, EDSS scores at diagnosis and last examination, and MRI findings. Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 28, Armonk, NY) was utilized for data analysis. Results Both fMS and sMS groups were comparable in age (43.55±12.50 and 42.35±10.61 years, respectively) and gender distribution (females: fMS 71.9%, sMS 71.3%). No significant difference was noted regarding disease onset age (fMS 29.83±10.77, sMS 30.42±9.7). Age of onset, final EDSS, and relapse rate didn't significantly vary among sMS, fMS with first-degree relatives having MS (fMS(1)), and fMS with second or third-degree relatives having MS (fMS(2)). The fMS group showed a significantly higher incidence of initial spinal cord lesions on MRI compared to the sMS group (38.6% vs. 17.3%; p<0.001). Within the fMS group, the presence of spinal cord lesions on initial MRI correlated with a higher relapse rate and elevated initial and final EDSS scores. Conclusion Despite overarching similarities between fMS and sMS, spinal cord lesions' prevalence and implications in fMS may point to a genetic underpinning warranting in-depth exploration.

Epidemiology of familial multiple sclerosis in Iran: a national registry-based study

Background

Admittedly, little is known about the epidemiological signatures of familial multiple sclerosis (FMS) in different geographical regions of Iran.

Objective

To determine the epidemiology and the risk of FMS incidence in several provinces of Iran with a different ethnic population including, Fars, Tehran, Isfahan (Persians), and Mazandaran (Mazanis), Kermanshah (Kurds), and Chaharmahal and Bakhtiari (Lors).

Methods

This cross-sectional registry-based study was performed on nationwide MS registry of Iran (NMSRI) data collected from 2018 to 2021. This system, registers baseline characteristics, clinical presentations and symptoms, diagnostic and treatments at regional and national levels.

Results

A total of 9200 patients including, 7003 (76.1%) female and 2197 (23.9%) male, were participated. About 19% of patients reported a family history of MS; the order from highest to lowest FMS prevalence was as follows: Fars (26.5%), Chaharmahal and Bakhtiari (21.1%), Tehran (20.5%), Isfahan (20.3%), Mazandaran (18.0%), and Kermanshah (12.5%). Of all FMS cases, 74.7% (1308 cases) were female and 25.3% (442 cases) were male. FMS occurrence was much more common in females than males (P-value = 0.001). Further, the mean age at onset was 30 years among FMS cases. A substantially higher probability of relapsing-remitting MS and secondary-progressive MS was found among FMS cases than sporadic MS (SMS) (P_value = 0.001). There was no significant difference in Expanded Disability Status Scale (EDSS) scores between FMS and SMS. The majority of FMS cases were observed among first-degree relatives, with the highest rate in siblings. There was a significant association between MS risk and positive familial history in both maternal and paternal aunt/uncle (P_value = 0.043 and P_value = 0.019, respectively). Multiple sclerosis occurrence among offspring of females was higher than males (P_value = 0.027).

Conclusions

In summary, our findings imply a noteworthy upward trend of FMS in Iran, even more than the global prevalence, which suggests a unique Atlas of FMS prevalence in this multi-ethnic population. Despite the highest rate of FMS within Persian and Lor ethnicities, no statistically significant difference was observed among the provinces.

The global prevalence of familial multiple sclerosis: an updated systematic review and meta-analysis

BACKGROUND

Considering that many recent studies have reported the prevalence of familial multiple sclerosis (FMS), we performed an updated meta-analysis of the worldwide prevalence of FMS by the addition of recent publications.

METHODS

A search in PubMed, Scopus, the ISI Web of Science, and Google Scholar was undertaken up to 20 December 2020. The inclusion criteria were based on the CoCoPop approach (condition, context, and population). Meta-analysis of the qualified studies was conducted by comprehensive meta-analysis ver. 2 software.

RESULTS

The pooled prevalence of MS in relatives of 16,179 FMS cases was estimated to be 11.8% (95% CI: 10.7-13) based on a random-effects model. The pooled mean age of disease onset in adult probands was calculated to be 28.7 years (95% CI: 27.2 ± 30.2). Regarding 13 studies that reported the data of FMS in pediatrics (n = 877) and adults (n = 6636), the FMS prevalence in pediatrics and adults was 15.5% (95% CI: 13.8-17.4) and 10.8% (95% CI: 8.1-14.2), respectively. The prevalence of FMS in affected males (n = 5243) and females (n = 11,503) was calculated to be 13.7% (95% CI: 10.1-18.2) and 15.4% (95% CI: 10.3-22.4), respectively. The odds ratio of male/female in FMS cases was not statistically significant (OR = 0.9; 95% CI: 0.6-1.2, P = 0.55). Subgroup analysis demonstrated a significant difference in the prevalence of FMS between the geographical areas (P = 0.007). The meta-regression model indicated that the prevalence of FMS is lower with higher latitude and higher MS prevalence (P < 0.001). In contrast, meta-regression based on prevalence day was not statistically significant (P = 0.29).

CONCLUSIONS

The prevalence of FMS is higher in the pediatric group than that of adults, distinct between geographical areas, and diminishes with the increment of MS prevalence and latitude. Also, the symptoms initiate relatively at younger ages in the FMS cases. Interestingly, our analysis unveiled that FMS is not more prevalent in men than women and the risk of MS development in relatives is not higher when the affected proband is male.

Multiple sclerosis projection in Tehran, Iran using Bayesian structural time series

BACKGROUND

The prevalence of Multiple Sclerosis (MS) has been increasing worldwide and the highest prevalence ratio among Asian countries was reported in Iran. This study aims to estimate the increase in MS occurrence during more than three decades in Tehran and forecast the future condition of the disease using time series approaches for the next ten years.

METHODS

The cross-sectional study was conducted from 1999 to 2019 based on records of MS cases from Iranian MS Society (IMSS) registry system. The prevalence was estimated using population data presented by the Statistical Centre of Iran. Through Bayesian Structural Time Series (BSTS) model, we want to predict the prevalence of familial and sporadic MS in the next ten years. .

RESULTS

Among 22,421 cases with MS, 16,831 (75.1 %) were female and 5589 (24.9 %) were male. Female to male ratio was 3.0:1 and the number of familial MS cases were 2982 (13.3 %) of subjects. Female gender was less responsible for higher rate of MS in familial definition (beta = 0.020) in comparison to sporadic cases (beta = 0.034). Forecasting by BSTS revealed an increase in MS prevalence for the next ten years so that the prevalence rate for total, familial and sporadic MS respectively begins with 189.50 (183.94-195.14), 25.69 (24.97-26.45) and 163.74(159.06-168.57) in 2020 and ends with 220.84 (171.48-266.92), 30.79 (24.16-37.15), and 189.33(146.97-230.19) in 2029.

CONCLUSIONS

According to the findings, MS prevalence increased during three decades and it will increase over the next ten years. Tehran province is one of the regions with highest MS prevalence in Asia. The results of present study indicated that females are at higher risk for MS than males in both sporadic and familial MS.

Gene expression profiles of YAP1, TAZ, CRB3, and VDR in familial and sporadic multiple sclerosis among an Iranian population

Alterations in the regulatory mechanisms that control the process of myelination in the nervous system, may lead to the impaired myelination in the Multiple sclerosis. The Hippo pathway is an important mediator of myelination in the nervous system and might contribute to the pathophysiology of MS. This study examined via qPCR the RNA expression of YAP1, TAZ, and CRB3 as the key effectors of the Hippo pathway and also, VDR in the peripheral blood of 35 sporadic, 37 familial MS patients; and also 34 healthy first-degree relatives of the familial MS patients (HFR) and 40 healthy individuals without a family history of the disease (control). The results showed the increased expression of VDR in the sporadic group, as compared to other groups. There was also an increased expression of TAZ in the familial and HFR groups, as compared to the control group. The familial and sporadic patients displayed a significantly lower level of expression of YAP1 in comparison to the HFR group. The increased expression level in the sporadic patients and control group, as compared to the HFR group, was seen in CRB3. We also assessed different clinical parameters and MRI characteristics of the patients. Overall, these findings suggest that Hippo pathway effectors and also VDR gene may play a potential role in the pathophysiology of the sporadic and familial forms of MS. Confirmation of different gene expression patterns in sporadic and familial MS groups may have obvious implications for the personalization of therapies in the disease.

Demographic and clinical characteristics of familial and sporadic multiple sclerosis: A single center exploratory study from Abu Dhabi

Demographic and clinical characteristics of Familial Multiple Sclerosis (FMS) have not been fully investigated yet in Abu Dhabi. The aim of this single center exploratory study was to investigate demographic and clinical characteristics of FMS compared to sporadic MS (SMS) in Abu Dhabi. A chart review single center study was conducted in 98 patients with MS. Group comparisons were performed using Mann-Whitney and Chi-Square tests as appropriate. A p < 0.05 was considered statistically significant. 24.5% were patients with FMS and 83% were Emirates. No significant differences in demographic and clinical characteristics were found between patients with FMS and SMS in overall all MS patients and in the Emirati group analyzed alone. Patients with FMS did not differ in demographic and clinical characteristics compared to patients with SMS. Further prospective studies are needed to elucidate environmental and genetic risk factors contributing to FMS in the Emirati population.