Anticipation of age at onset in multiple sclerosis: a Sardinian cohort study

Mitochondrial DNA haplogroup analysis in Saudi Arab patients with multiple sclerosis

Previous studies have suggested that mitochondrial DNA (mtDNA) variants are associated with multiple sclerosis (MS), a complex neurodegenerative immune-mediated disease of the central nervous system. Since mtDNA is maternally inherited without recombination, specific mtDNA variants defining genetic background are associated with the susceptibility to human diseases. To assess the contribution of mtDNA haplogroups to the predisposition of MS in an Arab population, we analysed sequencing data of mitochondrial genomes from 47 native Saudi Arab individuals including 23 patients with relapsing-remitting MS (RRMS) and 24 healthy controls. All patients and controls could be classified into ten haplogroups. The European-specific haplogroup U was more prevalent in patients than in the controls (26.1% vs. 4.2%), whereas haplogroup T was only present in patients and haplogroups HV and N were only found in controls. Haplogroup U was significantly association with increased risk of MS (odds ratio = 6.26, p<0.05), although the association did not maintain significance after adjustment for multiple comparisons. Haplotype U was more prevalent in patients with younger age of onset (p = 0.006), but there was no relationship between haplotype U and disease severity, disease duration or EDSS and age-matched carriers and non-carriers of haplogroup U (p>0.05). Definition site of haplogroup U include the variant m.12308A>G in MT-TL2 gene which was found to affect highly conserved position within the variable arm of tRNALeu(CUN) and thus may impact mitochondrial protein synthesis, and two other variants namely m.11467A>G in MT-ND4 gene and m.12372G>A in MT-ND5 gene which were previously linked with mitochondrial function. Despite the small number of subjects, which may limit the statistical power of the study, our results showed for the first time a possible contribution of haplogroup U to the predisposition to MS in an Arab population. These findings warrant further validation in a large cohort to distinguish a genuine effect specific to MS from a chance finding due to small sampling.

The age at onset of relapsing-remitting multiple sclerosis has increased over the last five decades

BACKGROUND

Patients with relapsing-remitting multiple sclerosis (RRMS) most commonly experience their first symptoms between 20 and 40 years of age. The objective of this study was to investigate how the age at which the first symptoms of RRMS occur has changed over the past decades.

METHODS

Patients who were followed up in our unit after an initial diagnosis of RRMS using the Poser or McDonald criteria and who experienced their first symptoms between January 1970 and December 2019 were included in the study. The cohort was divided into five groups according to the decade in which the first symptoms appeared. The age at disease onset was compared across decades. Changes in age were also determined after excluding patients with early-onset disease (<18 years of age) and those with late-onset disease (>50 years of age) to avoid bias.

RESULTS

The cohort included 1,622 patients with RRMS, 67.6% of whom were women. Among them, 5.9% and 4% had early-onset and late-onset disease, respectively. The mean age ± standard deviation at onset was 31.11 ± 9.82 years, with no differences between men and women. The mean ages at onset were 23.79 ± 10.19 years between 1970 and 1979, 27.86 ± 9.22 years between 1980 and 1989, 30.07 ± 9.32 years between 1990 and 1999, 32.12 ± 9.47 between 2000 and 2009, and 34.28 ± 9.83 years between 2010 and 2019. The ages at disease onset were progressively higher in the later decades; this trend was statistically significant (p < 0.001), with a Pearson linear correlation coefficient R of 0.264 and R² of 0.070 (p < 0.001). The results were similar when analysing men and women separately. We conducted an analysis of 1,460 patients (mean age at onset: 31.10 ± 7.99 years), after excluding patients with early-onset and late-onset disease. In this specific subgroup, the mean ages at disease onset were 28.38 ± 8.17 years between 1970 and 1979, 29.22 ± 7.51 years between 1980 and 1989, 30.06 ± 8.02 years between 1990 and 1999, 31.46 ± 7.77 years between 2000 and 2009, and 33.37 ± 7.97 years between 2010 and 2019. The trend was also statistically significant (p < 0.001), with a Pearson linear correlation coefficient R of 0.193 and R² of 0.037 (p < 0.001).

CONCLUSION

Our data showed that the age at RRMS onset has increased over the past decades.

Temporal trends in the incidence and prevalence of Multiple Sclerosis in the Northwest of Spain

BACKGROUND

During the last decades, the frequency of multiple sclerosis (MS) is increasing worldwide. Nevertheless, the higher sensibility of the new diagnostic criteria obscures the comparison between studies performed in different decades.

METHODS

The evolution of the frequency of MS in Santiago de Compostela (North-West of Spain) between 2003 and 2015 was analyzed using Poisson regression. The diagnosis was confirmed according to Poser criteria. Several sources were consulted for case ascertainment: databases from the MS Unit, the Infusion Center, and the Departments of Neurology, Pharmacy, Pediatric Neurology and Codification of the public Hospital of Santiago, private hospitals, neurologists with private activity, general practitioners, and associations of patients.

RESULTS

In 12 years, the prevalence increased from 68 to 143 cases/100,000 inhabitants, from 83 to 176 in females; and from 49 to 106 in males (p <0.0001, 0.0001, and 0.0002 respectively). The incidence rise was not significant (from 5 to 8 cases/ 100,000 inhabitants/ year (p=0.4243). The mean age of the population growth 5.7 years (p=0.008). The changes in female: male ratio (12.9%), in the age at the first symptom (2.2 years), and the diagnosis delay (0.12 years) did not achieve significance (p=0.7750, 0.1606, 0.8581).

CONCLUSION

The prevalence of MS doubled in 12 years whilst the difference in incidence was lower and not significant. The disproportion in the growth of both parameters, as well as the higher mean age in the last study, suggest a longer survival of patients with MS.

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.

Genetic Variants in TMEM39A Gene Are Associated with Autoimmune Thyroid Diseases

Transmembrane protein 39A (TMEM39A) gene polymorphisms have been related to various autoimmune diseases, but the relationship between TMEM39A polymorphisms and autoimmune thyroid disease (AITD) remains unknown. This study was aimed at investigating whether the polymorphisms of the TMEM39A were associated with AITD in the Chinese Han population. A case-control study was performed in a total of 906 AITD patients and 744 healthy controls. Four single nucleotide polymorphisms, including rs1132200, rs12492609, rs2282175, and rs7629750, in TMEM39A were examined by polymerase chain reaction-ligase detection reaction. We found that the allele T of rs12492609 in TMEM39A was associated with AITD and Hashimoto's thyroiditis (HT) (p = 0.023; p = 0.028 respectively). Compared with controls, the frequency of haplotype CCA in AITD patients was higher than that in controls (p = 0.036), but the frequency of haplotype CTA in AITD and HT patients was lower than that in controls (p = 0.046; p = 0.047 respectively). In addition, the frequency of allele A at rs7629750 in AITD patients with onset age ≤18 years old was higher than that in AITD patients with onset age ≥19 (p = 0.046). Further, there was an obvious difference in the genotype distributions of rs12492609 and rs7629750 between HT patients with hypothyroidism and those without hypothyroidism (p = 0.034 and p = 0.023, respectively). Our study first reveals that the polymorphisms of the TMEM39A gene are associated with the susceptibility to AITD, especially for early-onset AITD and HT with hypothyroidism.

TNFSF4 Gene Variations Are Related to Early-Onset Autoimmune Thyroid Diseases and Hypothyroidism of Hashimoto's Thyroiditis

The aim of the current study was to examine whether the polymorphism loci of the tumor necrosis factor superfamily member 4 (TNFSF4) gene increase the risk of susceptibility to autoimmune thyroid diseases (AITDs) in the Han Chinese population, and a case-control study was performed in a set of 1,048 AITDs patients and 909 normal healthy controls in the study. A total of four tagging single nucleotide polymorphisms (SNPs) in the TNFSF4 region, including rs7514229, rs1234313, rs16845607 and rs3850641, were genotyped using the method of ligase detection reaction. An association between GG genotype of rs3850641 in TNFSF4 gene and AITDs was found (p = 0.046). Additionally, the clinical sub-phenotype analysis revealed a significant association between GG genotype in rs7514229 and AITDs patients who were ≤18 years of age. Furthermore, rs3850641 variant allele G was in strong association with hypothyroidism in Hashimoto’s thyroiditis (HT) (p = 0.018). The polymorphisms of the TNFSF4 gene may contribute to the susceptibility to AITDs pathogenesis.

Differences in Gene-Gene Interactions in Graves' Disease Patients Stratified by Age of Onset

Background

Graves’ disease (GD) is a complex disease in which genetic predisposition is modified by environmental factors. Each gene exerts limited effects on the development of autoimmune disease (OR = 1.2–1.5). An epidemiological study revealed that nearly 70% of the risk of developing inherited autoimmunological thyroid diseases (AITD) is the result of gene interactions. In the present study, we analyzed the effects of the interactions of multiple loci on the genetic predisposition to GD. The aim of our analyses was to identify pairs of genes that exhibit a multiplicative interaction effect.

Material and Methods

A total of 709 patients with GD were included in the study. The patients were stratified into more homogeneous groups depending on the age at time of GD onset: younger patients less than 30 years of age and older patients greater than 30 years of age. Association analyses were performed for genes that influence the development of GD: HLADRB1, PTPN22, CTLA4 and TSHR. The interactions among polymorphisms were analyzed using the multiple logistic regression and multifactor dimensionality reduction (MDR) methods.

Results

GD patients stratified by the age of onset differed in the allele frequencies of the HLADRB1*03 and 1858T polymorphisms of the PTPN22 gene (OR = 1.7, p = 0.003; OR = 1.49, p = 0.01, respectively). We evaluated the genetic interactions of four SNPs in a pairwise fashion with regard to disease risk. The coexistence of HLADRB1 with CTLA4 or HLADRB1 with PTPN22 exhibited interactions on more than additive levels (OR = 3.64, p = 0.002; OR = 4.20, p < 0.001, respectively). These results suggest that interactions between these pairs of genes contribute to the development of GD. MDR analysis confirmed these interactions.

Conclusion

In contrast to a single gene effect, we observed that interactions between the HLADRB1/PTPN22 and HLADRB1/CTLA4 genes more closely predicted the risk of GD onset in young patients.

Disease onset in familial and sporadic multiple sclerosis in Argentina

The present study was carried out to assess if there is an anticipation of age at onset in younger generations of familial multiple sclerosis (FMS) vs. sporadic MS (SMS) in Argentina.

METHODS

multicenter study that included patients from 14 MS Centers of Argentina. Patients were considered as FMS if they had in their family at least one relative of first or second degree diagnosed with MS; otherwise, patients were considered to have SMS. We compared the age at onset between familial and sporadic cases as well as the age at onset between relatives from different generations in FMS vs. SMS.

RESULTS

1333 patients were included, 97 of them were FMS (7.3%). A lower age at onset in the younger generations of FMS cases was found compared with older generations of FMS as well as. SMS cases (24.1±3.7 years vs. 30.3±5.7 years, and 32.4±9.4 respectively; p<0.001). No differences were observed between older generations of FMS vs. SMS cases (p=0.12).

CONCLUSION

we observed an anticipation of age at onset of MS in younger generations of patients with FMS vs. older generations of FMS and SMS.

Higher weight in adolescence and young adulthood is associated with an earlier age at multiple sclerosis onset

BACKGROUND

Growing evidence suggests an association between adolescent obesity and increased risk of multiple sclerosis (MS).

OBJECTIVE

The objective of this paper is to investigate whether weight or body mass index (BMI) in adolescence and young adulthood was associated with age at MS symptom onset.

METHODS

Our cohort is comprised of a sub-group of 184 women enrolled in the New York State MS Consortium registry. Individuals were asked to recall their weight at the time of first menstruation and at age 25. BMI was calculated accordingly for age 25. Regression analyses were carried out to investigate the association between weight or BMI and age at onset.

RESULTS

Weight at menarche was significantly related to younger age at symptom onset (β = -0.073, p = 0.001). These results were also found at age 25 for weight (β = -0.080, p < 0.001) and BMI (β = -0.448, p = 0.001). Significantly earlier disease onset (26.9 years ±9.9) was observed in individuals who were overweight at 25 compared to those who were not overweight (32.1 years ±9.2, p = 0.006).

CONCLUSIONS

Women who reported higher weight in adolescence and BMI in early adulthood were younger at MS onset. Future research should investigate whether there is a causal link between body weight and MS, as prevention lifestyle and dietary interventions could be implemented.

Association between age at diagnosis of Graves' disease and variants in genes involved in immune response

Background

Graves' disease (GD) is a complex disease in which genetic predisposition is modified by environmental factors. The aim of the study was to examine the association between genetic variants in genes encoding proteins involved in immune response and the age at diagnosis of GD.

Methods

735 GD patients and 1216 healthy controls from Poland were included into the study. Eight genetic variants in the HLA-DRB1, TNF, CTLA4, CD40, NFKb, PTPN22, IL4 and IL10 genes were genotyped. Patients were stratified by the age at diagnosis of GD and the association with genotype was analysed.

Results

Polymorphism in the HLA-DRB1, TNF and CTLA4 genes were associated with GD. The carriers of the HLA DRB1*03 allele were more frequent in patients with age at GD diagnosis ≤30 years than in patients with older age at GD diagnosis.

Conclusions

HLADRB1*03 allele is associated with young age at diagnosis of Graves' disease in polish population.

Genetic and environmental backgrounds responsible for the changes in the phenotype of MS in Japanese subjects

There are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as opticospinal (OSMS) and conventional (CMS) forms. In Japan, the results of four nationwide surveys of MS conducted between 1972 and 2004 have revealed a four-fold increase in the estimated number of clinically definite MS patients in 2003 compared with 1972; a shift in the peak age at onset from the early 30s in 1989 to the early 20s in 2003; a successive proportional decrease in optic-spinal involvement in clinically definite MS patients; an increase in the number of CMS patients with Barkhof brain lesions with advancing birth year and a decrease in the number of OSMS patients with LESCLs. These findings suggest that MS phenotypes are drastically altered by environmental factors such as latitude and "Westernization". Helicobacter pylori infection rates, reflecting sanitary conditions in infancy, are significantly different between CMS and OSMS patients. Both phenotypes show distinct HLA class II gene associations. Therefore, changes in environmental factors may have differentially influenced susceptibility to each disease subtype, given that disease susceptibility is only partly genetically determined.

Temporal trends of disability progression in multiple sclerosis: findings from British Columbia, Canada (1975-2009)

BACKGROUND

Recent natural history studies suggest that multiple sclerosis (MS) is a more slowly progressing disease than previously thought. These observations are from studies separated by time, geography and methodological approach.

OBJECTIVES

We investigated whether MS disease progression has changed over time in British Columbia, Canada.

METHODS

The British Columbia MS database was queried for relapsing-onset MS patients with symptom onset from 1975 to <1995, first assessed within 15 years from onset and with at least two Expanded Disability Status Scale (EDSS) scores. Latest follow-up was to 2009. Patients were grouped by 5-year onset intervals (1975 to <1980, 1980 to <1985, 1985 to <1990, 1990 to <1995). Outcome was defined as time to reach sustained and confirmed EDSS 6 within 15 years of disease duration. Kaplan-Meier analysis was used to compare: the proportion of patients reaching EDSS 6 (primary analysis) and the time to EDSS 6 (secondary analysis) across the time-period groups.

RESULTS

A total of 2236 relapsing-onset MS patients (73.4% female; mean age at onset: 32.3 ± 8.8 years) were included. No significant temporal trend was found in the proportion of patients reaching EDSS 6 within 15 years from onset (28.5%, 26.4%, 27.7%, 22.3% for intervals 1975 to <1980, 1980 to <1985, 1985 to <1990, 1990 to <1995, respectively; p = 0.09) or in survival curves for time to reach the outcome (p = 0.14).

CONCLUSIONS

Rates of disease progression remained relatively stable over two decades of MS onset in British Columbia, Canada. Our results suggest that differences in disease progression findings between natural history studies may be related to factors other than time period.

Anticipation of age at onset in multiple sclerosis: methodologic pitfalls

BACKGROUND/AIM

There are several reports that claim anticipation in complex or polygenic diseases such as multiple sclerosis (MS), Crohn disease or schizophrenia. The aim of the present study was to assess age at onset of MS during the last 60 years in the region of Costa de Ponent (Barcelona, Spain) showing how apparent changes in age at onset between generations can be an artefact of analysis based on cohorts that have not been followed enough time.

METHODS

The study comprised 1100 patients diagnosed of MS. The method used to correct for follow-up time bias involves constructing comparison cohorts that had been observed for the same amount of time. To ensure equal follow-up times, we restricted our analysis to patients whose onset was by 37 years of age (percentile 75) and were at least 37 years old. We analysed differences in age at onset using log-rank test to compare survival curves estimated by Kaplan-Meier method.

RESULTS

Age at onset decreases progressively from older to younger generations. However, when adjustment to equal follow-up time was done, anticipation in age at onset was not found.

CONCLUSION

Anticipation of age at onset is undetectable when adjusted for follow-up time.

Anticipation of age at onset in familial multiple sclerosis

BACKGROUND AND OBJECTIVE

Anticipation of age at onset in the younger generations is a widely known characteristic of many diseases with genetic inheritance. This study was performed to assess whether there is anticipation of age at onset in younger generations of familial multiple sclerosis (MS) in a Spanish population and to compare clinical characteristics of familial and sporadic MS.

METHODS

We studied a cohort of 1110 patients diagnosed with MS and followed-up in our MS Unit. Patients were considered as familial MS if they had in their family at least one relative of first or second degree diagnosed with MS. Otherwise, patients were considered to have sporadic MS. We compared the age at onset between relatives from different generations, and we also compared the age at onset of familial and sporadic MS.

RESULTS

A lower age at onset in the younger generations was found (median 22 years vs. 30 years, P < 0.001) and a significant lower age at onset of the disease in familial MS comparing to sporadic MS (median 25 years vs. 29 years, P = 0.042).

CONCLUSIONS

There is an anticipation of the age at onset of MS in the younger generations of patients with familial MS. There is also a lower age at onset in familial versus sporadic MS.

Age of onset in concordant twins and other relative pairs with multiple sclerosis

The ages of onset in multiple sclerosis cases span more than 7 decades. Data are presented for affected relative pairs from a Canadian population base of 30,000 multiple sclerosis index cases (1993–2008). The effects of genetic sharing, parent of origin, intergenerational versus collinear differences, and gender on the ages of onset were evaluated in the following concordant pairs: monozygotic twins (n = 29), dizygotic twins (n = 10), siblings (n = 614), first cousins (n = 405), half siblings (n = 29), parent/child (n = 285), and aunt/uncle/niece/nephew (avunculars) (n = 289). Fisher's z test assessed intraclass correlation (r) for ages of onset. Correlations for monozygotic twins, dizygotic twins, full siblings, and first cousins were 0.60, 0.54, 0.20, and 0.10, respectively. Dizygotic twins resembled monozygotic twins more than siblings. The age-of-onset correlation for maternal half siblings (r = 0.37) was higher than that for paternal half siblings (r = 0.26), consistent with other observations suggesting an intrauterine environmental effect on multiple sclerosis risk. Intergenerational comparisons are complicated by substantial increases of multiple sclerosis incidence over time. Genetic loading (familial vs. sporadic cases) did not generally influence the age of onset, but correlation of age of onset in multiple sclerosis relative pairs was proportional to genetic sharing. A maternal parent-of-origin effect on the age of onset in collinear generations was suggested.

Multiple sclerosis risk: interaction between human leukocyte antigen and the environment in Sardinian population

Background

The island of Sardinia features a high incidence of multiple sclerosis (MS) characterized by early age at onset and a progressively increasing trend. The current study was aimed at examining variations in human leukocyte antigen–risk genotypes occurring over time in a cohort of patients.

Methods

Susceptible and neutral DRB1-DQB1 genotypes were identified in 1660 patients. Age at onset was established in 1436 patients divided into two cohorts, an older cohort (subjects born before 1949, N = 233) and a younger one (subjects born from 1960 to 1989, N = 850). Patients from the older cohort were randomly assigned to patients of the same sex from the younger cohort, matched for age at onset. The final sample included 170 pairs. Logistic conditional analysis was performed to determine the probability of a neutral genotype in both cohorts. Kaplan–Meier analysis was applied to ascertain the influence of predisposing and neutral genotypes in age at onset for both cohorts.

Findings

The probability of carrying a neutral genotype was 1.76-fold higher in the younger than in the older cohort ( P = 0.02) and 3.67-fold higher in men ( P = 0.005). Kaplan–Meier analysis revealed an earlier age at onset in patients of the young cohort carrying the predisposing genotype ( P = 0.004).

Interpretation

In the Sardinian population, an environment more prone and propitious to autoimmunity may contribute toward the rising incidence of MS or anticipate overt manifestation of the disease in genetically predisposed subjects.

Mitochondrial mutation in Iranian patients with multiple sclerosis, correlation between haplogroups H, A and clinical manifestations

As multiple sclerosis (MS) has long been known to be associated with Leber, hereditary optic neuropathy (LHON), a disease caused by mitochondrial (mtDNA) mutations, in this study we assessed possible involvement of mtDNA point mutation in MS patients. Fifty-two MS patients whose disease was confirmed with revised McDonald criteria and referred to Iranian Center of Neurological Research of Imam Khomeini hospital during 2006-2007 entered the study. Secondary mtDNA mutations, age, gender, clinical disability according to expanded disability status scale (EDSS), course of the disease, and presenting symptoms were the variables investigated in this study. DNA purification was performed by Diatom DNA Extraction Kit. Analysis of data was done by SPSS V11.5. The prevalent mutations with frequency of 19.2% were J, L, and T haplogroups. Haplotype A was more prevalent in patients with younger age of onset (P-value = 0.012) and high proportion of haplogroup H was associated with optic nerve involvement (P-value = 0.015). No motor symptoms were seen in haplogroup H patients. There is no significant relationship between duration of the disease and EDSS in different mutation of mtDNA.

Temporal changes and geographical differences in multiple sclerosis phenotypes in Japanese: nationwide survey results over 30 years

Background

There are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as optic-spinal (OSMS) and conventional (CMS) forms. In Japan, four nationwide surveys of MS have been conducted. The first three were in 1972, 1982, and 1989, and we performed the fourth in 2004.

Results

The recent survey showed six main findings as follows: (1) a four-fold increase in the estimated number of clinically definite patients with MS in 2003 (9900; crude MS prevalence, 7.7/100,000) compared with 1972; (2) a shift in the peak age at onset from early 30s in 1989 to early 20s in 2003; (3) a successive proportional decrease in optic-spinal involvement in clinically definite patients with MS; (4) a significant north–south gradient for the CMS/OSMS ratio; (5) after subdivision of the mainland (30–45° North) into northern and southern parts at 37°N, northern-born northern residents (northern patients) showed a significantly higher CMS/OSMS ratio and higher frequency of brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) than southern-born southern residents (southern patients); (6) among northern patients, the absolute numbers of patients with CMS and those with Barkhof brain lesions rapidly increased with advancing birth year.

Conclusions

These findings suggest that MS phenotypes are drastically altered by environmental factors, such as latitude and “Westernization.”

Multiple sclerosis in the province of Ferrara : evidence for an increasing trend

BACKGROUND

Epidemiological studies on the distribution of multiple sclerosis (MS) conducted in the Mediterranean area in the last two decades have disclosed a significant increase in frequency of the disease, indicating caution when a latitude-related model of MS is accepted. Previous descriptive surveys in the province of Ferrara, northern Italy, carried out by our own epidemiological research group, have established that this area is at high risk for MS.

OBJECTIVE

To confirm the above assumption and to update MS frequency estimates in this area.

DESIGN AND SETTING

We conducted a community-based intensive prevalence and incidence study, by adopting a complete enumeration approach.

RESULTS

On December 31, 2004, 423 patients (300 women and 123 men) suffering from definite or probable MS (Poser's criteria) living in the province of Ferrara, yielded a crude prevalence rate of 120.93 (95 % CI, 110.05-134.23) per 100,000, 164.26 for women and 73.59 for men. The average incidence from 1990 to 2003 was 4.35 per 100,000 (95 % CI, 3.77-4.99), 5.91 for women and 2.63 for men. The incidence rate,which was relatively stable during the previous 25 years (1965-1989) with a mean rate of 2.3 per 100,000, increased to a value of 3.39 per 100,000 in the period 1990-1994, 4.09 per 100,000 in the period 1995-1999 and 3.84 per 100,000 in the period 2000-2003.

CONCLUSIONS

These results confirm that in Ferrara MS occurs more frequently than suggested by the geographic- related distribution model and, based on other recent national surveys, support the view that northern Italy is a high-risk area for the disease. The marked increase in MS prevalence rate, in comparison with previous investigations, is in part due to the increasing survival of patients as a result of improved supportive care and the accumulation of new incidence cases owing to the reduction in diagnostic latency for better quality of neurological diagnostic procedures. The incidence in the province of Ferrara was found to slowly change with an incremental trend,which cannot only be attributed to improvements in diagnostic ability. Environmental risk factors in genetically predisposed people over time could be considered.

The influence of parental age and gender on anticipation in familial B-cell malignancies

Anticipation occurs when a disease manifests at an earlier age and/or with an increased clinical severity in the next generation. Its relationship with parental age and gender is relevant to the patterns of genetic transmission of familial B-cell neoplasms. One hundred and sixty pairs [44 non-Hodgkin's lymphoma (NHL), 38 Hodgkin's disease (HD), 48 HD/NHL, and 30 CLL] were analyzed retrospectively for presence of anticipation in paternal (PT), maternal (MT), and overall transmission. Overall mean anticipation measured -23.0 yr, and varied between -18.93 and -26.46 yr with no significant difference among different diseases, except between CLL and mixed HD/NHL (mean difference -7.68 yr, p = 0.03). A significant Pearson correlation (PC) between the parental age at conception and anticipation was found for all malignancies (PC = -0.339, p < 0.0001), with the exception of mixed HD/NHL pairs of MT. Higher PCs were observed with PT than MT for all diseases. Anticipation manifests in all familial B-cell malignancies analyzed and it correlates with the parental age at conception. Although less prominent than with neurological disease, this phenomenon indicates a possible germline inheritance of B-cell malignancies and a common genetic basis for HD and NHL.

Anticipation in families with Hodgkin's and non-Hodgkin's lymphoma in their pedigree

Anticipation is an earlier onset and/or increasing severity in successive generations. This study was conducted to determine whether anticipation occurs in families that exhibit both Hodgkin's (HD) and non-Hodgkin's (NHL) lymphoma in their pedigrees. Nine published reports of multi-generational lymphoma and 33 previously unreported families with both lymphomas were analysed for evidence of anticipation. The difference between age at onset for each affected related pair was tested against the null hypothesis that there is no difference in age at onset. Differences between disease-free survival in affected generations were determined. These analyses were also conducted separately using only parent - child pairs with an age of onset above 25 years in an effort to avoid ascertainment bias. Age at onset in studied cases was also compared with the HD and NHL series from the Surveillance Epidemiology and End Results (SEER) Program of the US National Cancer Institute. The mean age at onset in the child and parent generations of all case families (60.2 and 35.7 years, respectively) and in the selected pairs (61.5 and 45.6, years) were significantly different (mean difference -24.5 years; P < 0.00001, and -15.9 years, P < 0.00001, respectively). Mean anticipation for parents with HD and children with NHL was -6.8 years (P = 0.01) for the unpublished and -14.4 years (P = 0.002) for the published families (overall anticipation -10.1 years). Mean anticipation for parents with NHL and children with HD was -34.4 years (P < 0.0001) for the unpublished and -32.7 years (P < 0.0001) for the published families (overall anticipation -34.2 years, P < 0.0001). The signed rank test rejected the null hypothesis which stated that there was no difference in age at onset between parents and children for overall, as well as selected pairs (P < 0.00001). The null hypothesis was also rejected for both the parents with HD/children with NHL group and the parents with NHL/children with HD group pairs (P < 0.0001). Age at onset distributions were significantly different for all generations with HD or NHL when compared to the SEER population (P < 0.00001), except for the parents with NHL, which showed no difference. In addition, this study reports four previously unpublished families with three generations of lymphoma in their pedigrees. These data suggest that anticipation occurs in families that exhibit both HL and NHL and that both neoplasms may have a common genetic basis.

Influences of age, gender, smoking, and family history on autoimmune thyroid disease phenotype

CONTEXT

Both genetic and environmental factors contribute to susceptibility to Graves' disease (GD) and Hashimoto's thyroiditis (HT), as well as disease manifestations.

OBJECTIVE

The objective of the study was to define how endogenous/environmental factors contribute to variation in phenotype.

DESIGN/SETTING

This was a multicenter cohort study. PATIENTS/OUTCOME MEASURES: We prospectively collected clinical/biochemical data as part of the protocol for a United Kingdom DNA collection for GD and HT. We investigated, in 2805 Caucasian subjects, whether age at diagnosis, gender, family history (FH), smoking history, and presence of goiter influenced disease manifestations.

RESULTS

For 2405 subjects with GD, the presence of goiter was independently associated with disease severity (serum free T4 at diagnosis) (P < 0.001). Free T4 (P < 0.05) and current smoking (P < 0.001) were both independent predictors of the presence of ophthalmopathy. Approximately half of those with GD (47.4% of females, 40.0% of males) and HT (n = 400) (56.4% of females, 51.7% of males) reported a FH of thyroid dysfunction. In GD, a FH of hyperthyroidism in any relative was more frequent than hypothyroidism (30.1 vs. 24.4% in affected females, P < 0.001). In HT, a FH of hypothyroidism was more common than hyperthyroidism (42.1 vs. 22.8% in affected females, P < 0.001). For GD (P < 0.001) and HT (P < 0.05), a FH was more common in maternal than paternal relatives. The reporting of a parent with thyroid dysfunction (hyper or hypo) was associated with lower median age at diagnosis of both GD (mother with hyperthyroidism, P < 0.001) and HT (father with hypothyroidism, P < 0.05). In GD and HT, there was an inverse relationship between the number of relatives with thyroid dysfunction and age at diagnosis (P < 0.01).

CONCLUSIONS

Marked associations among age at diagnosis, disease severity, goiter, ophthalmopathy, smoking, and FH provide evidence for interactions between genetic and environmental/endogenous factors; understanding these may allow preventive measures or better tailoring of therapies.

Increasing Incidence of Multiple Sclerosis in the Province of Sassari, Northern Sardinia

Sardinia is a high-risk area for multiple sclerosis (MS), with prevalence rates of 150 per 100,000 population. The study included 689 MS patients (female-male ratio 2.6) with disease onset between 1965 and 1999 in the province of Sassari. The mean annual incidence rate increased significantly from 1.1 per 100,000 population in 1965-1969 to 5.8 in 1995-1999, with no significant difference for gender and province sub-areas. The mean age at onset increased significantly during the same period from 25.7 to 30.6 years, while the proportion of patients with progressive initial course declined over time. The marked increase of MS incidence and the change of MS clinical phenotype over time cannot be explained by ascertainment bias only, thus pointing to a corresponding change in the distribution of exogenous risk factors in this highly genetically stable population.

Genes, environment, and susceptibility to multiple sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system affecting young adults and thus representing a major burden also for their families and communities. The etiology of MS is obscure and its pathogenesis is yet incompletely depicted. Increased evidences indicate a strong genetic contribution to MS susceptibility, although others support the view that it is also influenced by environmental factors, possibly related to still unidentified pathogens. MS appears to be more heterogeneous than previously believed at the immunological level, and new pathological studies indicate a series of subset of conditions under the common denominator MS. The use of genetically homogeneous and geographically isolated populations at high MS risk, such as that of Sardinia, insular Italy, becomes in principle a vital requirement to reduce biological variables and the intrinsic complexity of the disease. This review will focus on recent findings on the peculiarity of Sardinian MS concerning epidemiological, genetic, and environmental aspects. Epidemiological studies reveal a clear heterogeneous distribution of MS cases in the Northern province of Sassari which may not be uniquely assigned to genetic variations. Furthermore, a different immunogenetic profile, including the association with other immunomediated diseases, and a progressive change in clinical phenotype, including age at onset, are present in this island which gives us unexpected variations at the level of patients' cohort and territorial distribution, especially when the northern province is compared to the southern one. This renders MS etiopathogenesis more complex than formerly thought even in this selected and genetically stable population.