Long-term clinical outcomes in patients with CIS treated with interferon beta-1b: results from the 15-year follow up of the BENEFIT trial

Multiple sclerosis (MS) treatment intervention with immunomodulating therapy at early disease stage improves short term clinical outcomes. The objective of this study is to describe the long-term outcomes and healthcare utilization of patients with clinically isolated syndrome (CIS) included in the Betaferon®/Betaseron® in Newly Emerging MS for Initial Treatment (BENEFIT) randomized, parallel group trial. In BENEFIT patients were assigned to "early" IFNB-1b treatment or placebo ("delayed" treatment). After 2 years or conversion to clinically definite multiple sclerosis (CDMS), all patients were offered IFNB-1b and were reassessed 15 years later. Of 468 patients, 261 (55.8%) were enrolled into BENEFIT 15 (161 [55.1%] from the early, 100 [56.8%] from the delayed treatment arm). In the full BENEFIT analysis set, risk of conversion to CDMS remained lower in the early treatment group ( - 30.5%; hazard ratio 0.695 [95% CI, 0.547-0.883]; p = 0.0029) with a 15.7% lower risk of relapse than in the delayed treatment group (p = 0.1008). Overall, 25 patients (9.6%; 9.9% early, 9.0% delayed) converted to secondary progressive multiple sclerosis. Disability remained low and stable with no significant difference between groups in Expanded Disability Status Scale score or MRI metrics. Paced Auditory Serial Addition Task-3 scores were better in the early treatment group (p = 0.0036 for treatment effect over 15 years). 66.3% of patients were still employed at Year 15 versus 74.7% at baseline. In conclusion, results 15 years from initial randomization support long-term benefits of early treatment with IFNB-1b.

Body mass index as a predictor of MS activity and progression among participants in BENEFIT

BACKGROUND

There is a lack of studies on the association between obesity and conversion from a clinically isolated syndrome (CIS) to multiple sclerosis (MS).

OBJECTIVE

The aim of this study was to determine whether obesity predicts disease activity and prognosis in patients with CIS.

METHODS

Body mass index (BMI) at baseline was available for 464 patients with CIS in BENEFIT. Obesity was defined as BMI ⩾ 30 kg/m² and normal weight as 18.5 ⩽ BMI < 25. Patients were followed up for 5 years clinically and by magnetic resonance imaging. Hazard of conversion to clinically definite (CDMS) or to 2001 McDonald criteria (MDMS) MS, annual rate of relapse, sustained progression on Expanded Disability Status Scale (EDSS), change in brain and lesion volume, and development of new brain lesions were evaluated.

RESULTS

Obese individuals were 39% more likely to convert to MDMS (95% CI: 1.02-1.91, p = 0.04) and had a 59% (95% CI: 1.01-2.31, p = 0.03) higher rate of relapse than individuals with normal weight. No associations were observed between obesity and conversion to CDMS, sustained progression on EDSS or magnetic resonance imaging (MRI) outcomes, except for a larger reduction of brain volume in obese smokers as compared to normal weight smokers (-0.82%; 95% CI: -1.51 to -0.12, p = 0.02).

CONCLUSION

Obesity was associated with faster conversion to MS (MDMS) and a higher relapse rate.

Real-World Assessment of Interferon-β-1b and Interferon-β-1a Adherence Before and After the Introduction of the BETACONNECT® Autoinjector: A Retrospective Cohort Study

BACKGROUND

Both interferon beta-1b (IFN-β-1b) and interferon beta-1a (IFN-β-1a) are immunomodulators that require regular subcutaneous self-administration by patients with multiple sclerosis (MS). However, no electronic autoinjector is available for IFN-β-1a in the US.

OBJECTIVE

This retrospective cohort study investigated adherence to two subcutaneous disease-modifying therapies, IFN-β-1b and IFN-β-1a, during two periods (before and after the introduction of the BETACONNECT® autoinjector for IFN-β-1b).

PATIENTS AND METHODS

Data were evaluated from the MarketScan database for adults in the US with an MS diagnosis and a medical claim for subcutaneous IFN-β-1b or IFN-β-1a, either before (October 2013-September 2015) or after the introduction of BETACONNECT (October 2016-September 2018). Patient populations were propensity-score matched by demographic and clinical characteristics. Persistence was recorded, and adherence was evaluated by medication possession ratio (MPR).

RESULTS

The study included 196 IFN-β-1b and 365 IFN-β-1a people with MS (PwMS) (pre-BETACONNECT period), and 126 IFN-β-1b and 223 IFN-β-1a PwMS (post-BETACONNECT period). In the pre-BETACONNECT period, the proportion with at least 80% MPR was higher for IFN-β-1a (90%) than for IFN-β-1b (83%), but in the post-BETACONNECT period the proportion with ≥ 80% MPR was higher for IFN-β-1b (92%) than for IFN-β-1a (86%). In the pre-BETACONNECT period, median persistence (in days) was higher for IFN-β-1a (199) than for IFN-β-1b (152), while in post-BETACONNECT period persistence was higher for IFN-β-1b (327) than for IFN-β-1a (229).

CONCLUSIONS

Following the introduction of BETACONNECT, this exploratory study suggested that PwMS taking IFN-β-1b were more adherent compared with those taking IFN-β-1a, with higher persistence, and more than 90% reached 80% MPR, a threshold commonly used to define good adherence.

Clinical characteristics of middle-aged and older patients with MS treated with interferon beta-1b: post-hoc analysis of a 2-year, prospective, international, observational study

Background

Despite trends towards the increased age of patients living with multiple sclerosis (MS), little is known about the response of older adults with MS to disease-modifying therapies (DMTs). Thus, a post-hoc analysis was undertaken using data from a 2-year, international, non-interventional, prospective cohort study (NCT00787657; BEACON: BEtaferon prospective study on Adherence, COping and Nurse support) of patients above the age of 40 years with MS and starting interferon beta-1b (IFNB-1b) treatment within 6 months before study entry.

Methods

Middle-aged and older patients with MS were divided into two sub-groups: 41–50 years and > 50 years. Treatment with IFNB-1b started within 6 months before study entry. Patients were followed-up for a 2-year observation period. Assessments included disease history and course, annualised relapse rate (ARR), Expanded Disability Scale Score (EDSS), treatment adherence, Hospital Anxiety and Depression Scale (HADS), and adverse events (AE).

Results

At baseline, the intention-to-treat (ITT) population (n = 481) aged 41–50 years (n = 327) and > 50 years (n = 154), had mean (standard deviation [SD]) ages of 45.1 (2.8) and 56.2 (4.2) years, maximum age of 72 years, and duration of MS since onset of symptoms of 3.9 (5.2) and 5.9 (7.1) years, respectively. At baseline, the proportion of patients with relapsing–remitting MS (RRMS) was 96.3 and 94.9 %, and secondary progressive MS (SPMS) was 3.7 and 5.1 %, in the 41–50 and > 50 years sub-groups, respectively. The ARR in the 2 years before study start was 0.93 (0.48) and 0.86 (0.54) for the 41–50 and > 50 years groups, respectively, and decreased since study start to 0.20 (1.09) and 0.07 (0.37), respectively. The percentage of patients with anxiety and depression, as measured by HADS, were stable over the study period. Polypharmacy (five or more medications) was seen in 32.3 and 41.2 % of patients aged 41–50 and > 50 years. No unexpected AEs were reported.

Conclusions

This study provides observational data on patients between 40 and 72 years of age, suggesting that IFNB-1b can be an effective and well-tolerated treatment option in MS patients of advanced age.

Trial registration

ClinicalTrials.gov, NCT00787657.

Vitamin D, smoking, EBV, and long-term cognitive performance in MS: 11-year follow-up of BENEFIT

OBJECTIVE

To investigate whether vitamin D, smoking, and anti-Epstein-Barr virus (EBV) antibody concentrations predict long-term cognitive status and neuroaxonal injury in multiple sclerosis (MS).

METHODS

This study was conducted among 278 patients with clinically isolated syndrome who participated in the clinical trial BENEFIT (Betaferon/Betaseron in Newly Emerging Multiple Sclerosis for Initial Treatment) and completed the 11-year assessment (BENEFIT-11). We measured serum 25-hydroxyvitamin-D (25(OH)D), cotinine (smoking biomarker), and anti-Epstein-Barr virus nuclear antigen 1 (EBNA-1) immunoglobulin G (IgG) at baseline and at months 6, 12, and 24 and examined whether these biomarkers contributed to predict Paced Auditory Serial Addition Test (PASAT)-3 scores and serum neurofilament light chain (NfL) concentrations at 11 years. Linear and logistic regression models were adjusted for sex, baseline age, treatment allocation, steroid treatment, multifocal symptoms, T2 lesions, and body mass index.

RESULTS

Higher vitamin D predicted better, whereas smoking predicted worse cognitive performance. A 50-nmol/L higher mean 25(OH)D in the first 2 years was related to 65% lower odds of poorer PASAT performance at year 11 (95% confidence intervals [95% CIs]: 0.14-0.89). Standardized PASAT scores were lower in smokers and heavy smokers than nonsmokers (p _trend = 0.026). Baseline anti-EBNA-1 IgG levels did not predict cognitive performance (p _trend = 0.88). Associations with NfL concentrations at year 11 corroborated these findings-a 50-nmol/L higher mean 25(OH)D in the first 2 years was associated with 20% lower NfL (95% CI: -36% to 0%), whereas smokers had 20% higher NfL levels than nonsmokers (95% CI: 2%-40%). Anti-EBNA-1 antibodies were not associated with NfL.

CONCLUSIONS

Lower vitamin D and smoking after clinical onset predicted worse long-term cognitive function and neuronal integrity in patients with MS.

Pregnancy outcomes from the global pharmacovigilance database on interferon beta-1b exposure

BACKGROUND

The goal of the present cohort study was to review outcomes of patients exposed to interferon beta-1b during pregnancy.

METHODS

Pregnancy cases with exposure to interferon beta-1b reported to Bayer's pharmacovigilance (PV) database from worldwide sources from January 1995 through February 2018 were retrieved for evaluation. Only cases where pregnancy outcomes were unknown at the time of reporting (i.e. prospective cases) were included in the analysis of this retrospective cohort study.

RESULTS

As of February 2018, 2581 prospective pregnancies exposed to interferon beta-1b were retrieved from the database; 1348 pregnancies had documented outcomes. The majority of outcomes [1106 cases (82.0%)] were live births. Health status was known for 981 live births (no known health status for 125). Most of the prospective pregnancies with known outcomes corresponded to live births with no congenital anomalies [896 cases (91.3%)]. Spontaneous abortion occurred in 160 cases (11.9%). Congenital birth defects were observed in 14/981 live births with known health status [1.4%, 95% confidence interval (CI) 0.78-2.38]. No consistent pattern in the type of birth defect was identified. Rates of both spontaneous abortion and birth defects were not higher than the general population.

CONCLUSIONS

These PV data, the largest sample of interferon beta-1b-exposed patients reported to date, suggest no increase in risk of spontaneous abortion or congenital anomalies in women exposed during pregnancy.

MRI-based prediction of conversion from clinically isolated syndrome to clinically definite multiple sclerosis using SVM and lesion geometry

Neuroanatomical pattern classification using support vector machines (SVMs) has shown promising results in classifying Multiple Sclerosis (MS) patients based on individual structural magnetic resonance images (MRI). To determine whether pattern classification using SVMs facilitates predicting conversion to clinically definite multiple sclerosis (CDMS) from clinically isolated syndrome (CIS). We used baseline MRI data from 364 patients with CIS, randomised to interferon beta-1b or placebo. Non-linear SVMs and 10-fold cross-validation were applied to predict converters/non-converters (175/189) at two years follow-up based on clinical and demographic data, lesion-specific quantitative geometric features and grey-matter-to-whole-brain volume ratios. We applied linear SVM analysis and leave-one-out cross-validation to subgroups of converters (n = 25) and non-converters (n = 44) based on cortical grey matter segmentations. Highest prediction accuracies of 70.4% (p = 8e-5) were reached with a combination of lesion-specific geometric (image-based) and demographic/clinical features. Cortical grey matter was informative for the placebo group (acc.: 64.6%, p = 0.002) but not for the interferon group. Classification based on demographic/clinical covariates only resulted in an accuracy of 56% (p = 0.05). Overall, lesion geometry was more informative in the interferon group, EDSS and sex were more important for the placebo cohort. Alongside standard demographic and clinical measures, both lesion geometry and grey matter based information can aid prediction of conversion to CDMS.

Predictive validity of NEDA in the 16- and 21-year follow-up from the pivotal trial of interferon beta-1b

BACKGROUND

Long-term follow-up from the randomized trial of interferon beta-1b (IFNB-1b) permitted the assessment of different definitions of no evidence of disease activity (NEDA) for predicting long-term outcome in multiple sclerosis (MS).

OBJECTIVE

To examine the predictive validity of different NEDA definitions.

METHODS

Predictive validity for negative disability outcomes (NDOs) at 16 years and survival at 21 years post-randomization were assessed. NEDA in the first 2 years was defined as follows: clinical NEDA: no relapses or Expanded Disability Status Scale (EDSS) progression from baseline to Year 2; NEDA-3a: no relapses, no confirmed ⩾1-point EDSS progression, and no new T2-active lesions; NEDA-3b: no relapses, no EDSS progression, and no increase in T2 burden of disease (T2-BOD); and NEDA-4: no relapses, no EDSS progression, and no increase in T2-BOD or atrophy. NDOs were defined as death, need for wheelchair, EDSS ⩾6, or progressive MS.

RESULTS

A total of 245 and 371 patients were evaluated at 16 and 21 years, respectively. Clinical NEDA predicted NDOs ( p = 0.0029), as did baseline EDSS ( p < 0.0001), baseline T2-BOD ( p < 0.0001), and change in T2-BOD ( p = 0.0033). IFNB-1b treatment ( p = 0.0251), relapse rate in the 2 years before study start ( p = 0.0260), T2-BOD at baseline ( p = 0.0014), and change in T2-BOD ( p = 0.0129) predicted survival at 21 years.

CONCLUSION

Clinical NEDA predicted long-term disability outcome. By contrast, definitions of NEDA that included on-therapy changes in magnetic resonance imaging variables did not increase the predictive validity.

Effect of HLA-DRB1 alleles and genetic variants on the development of neutralizing antibodies to interferon beta in the BEYOND and BENEFIT trials

BACKGROUND

Treatment of multiple sclerosis (MS) with interferon β can lead to the development of antibodies directed against interferon β that interfere with treatment efficacy. Several observational studies have proposed different HLA alleles and genetic variants associated with the development of antibodies against interferon β.

OBJECTIVE

To validate the proposed genetic markers and to identify new markers.

METHODS

Associations of genetic candidate markers with antibody presence and development were examined in a post hoc analysis in 941 patients treated with interferon β-1b in the Betaferon^® Efficacy Yielding Outcomes of a New Dose (BEYOND) and BEtaseron^®/BEtaferon^® in Newly Emerging multiple sclerosis For Initial Treatment (BENEFIT) prospective phase III trials. All patients were treated with interferon β-1b for at least 6 months. In addition, a genome-wide association study was conducted to identify new genetic variants.

RESULTS

We confirmed an increased risk for carriers of HLA-DRB1*04:01 (odds ratio (OR) = 3.3, p = 6.9 × 10^-4) and HLA-DRB1*07:01 (OR = 1.8, p = 3.5 × 10^-3) for developing neutralizing antibodies (NAbs). Several additional, previously proposed HLA alleles and genetic variants showed nominally significant associations. In the exploratory analysis, variants in the HLA region were associated with NAb development at genome-wide significance (OR = 2.6, p = 2.30 × 10^-15).

CONCLUSION

The contribution of HLA alleles and HLA-associated single-nucleotide polymorphisms (SNPs) to the development and titer of antibodies against interferon β was confirmed in the combined analysis of two multi-national, multi-center studies.

Sodium intake and multiple sclerosis activity and progression in BENEFIT

OBJECTIVE

To assess whether a high-salt diet, as measured by urinary sodium concentration, is associated with faster conversion from clinically isolated syndrome (CIS) to multiple sclerosis (MS) and MS activity and disability.

METHODS

BENEFIT was a randomized clinical trial comparing early versus delayed interferon beta-1b treatment in 465 patients with a CIS. Each patient provided a median of 14 (interquartile range = 13-16) spot urine samples throughout the 5-year follow-up. We estimated 24-hour urine sodium excretion level at each time point using the Tanaka equations, and assessed whether sodium levels estimated from the cumulative average of the repeated measures were associated with clinical (conversion to MS, Expanded Disability Status Scale [EDSS]) and magnetic resonance imaging (MRI) outcomes.

RESULTS

Average 24-hour urine sodium levels were not associated with conversion to clinically definite MS over the 5-year follow-up (hazard ratio [HR] = 0.91, 95% confidence interval [CI] = 0.67-1.24 per 1g increase in estimated daily sodium intake), nor were they associated with clinical or MRI outcomes (new active lesions after 6 months: HR = 1.05, 95% CI = 0.97-1.13; relative change in T2 lesion volume: -0.11, 95% CI = -0.25 to 0.04; change in EDSS: -0.01, 95% CI = -0.09 to 0.08; relapse rate: HR = 0.78, 95% CI = 0.56-1.07). Results were similar in categorical analyses using quintiles.

INTERPRETATION

Our results, based on multiple assessments of urine sodium excretion over 5 years and standardized clinical and MRI follow-up, suggest that salt intake does not influence MS disease course or activity. Ann Neurol 2017;82:20-29.

The 11-year long-term follow-up study from the randomized BENEFIT CIS trial

Objective:

To assess outcomes for patients treated with interferon beta-1b immediately after clinically isolated syndrome (CIS) or after a short delay.

Methods:

Participants in BENEFIT (Betaferon/Betaseron in Newly Emerging MS for Initial Treatment) were randomly assigned to receive interferon beta-1b (early treatment) or placebo (delayed treatment). After conversion to clinically definite multiple sclerosis (CDMS) or 2 years, patients on placebo could switch to interferon beta-1b or another treatment. Eleven years after randomization, patients were reassessed.

Results:

Two hundred seventy-eight (59.4%) of the original 468 patients (71.3% of those eligible at participating sites) were enrolled (early: 167 [57.2%]; delayed: 111 [63.1%]). After 11 years, risk of CDMS remained lower in the early-treatment arm compared with the delayed-treatment arm (p = 0.0012), with longer time to first relapse (median [Q1, Q3] days: 1,888 [540, not reached] vs 931 [253, 3,296]; p = 0.0005) and lower overall annualized relapse rate (0.21 vs 0.26; p = 0.0018). Only 25 patients (5.9%, overall; early, 4.5%; delayed, 8.3%) converted to secondary progressive multiple sclerosis. Expanded Disability Status Scale scores remained low and stable, with no difference between treatment arms (median [Q1, Q3]: 2.0 [1.0, 3.0]). The early-treatment group had better Paced Auditory Serial Addition Task–3 total scores (p = 0.0070). Employment rates remained high, and health resource utilization tended to be low in both groups. MRI metrics did not differ between groups.

Conclusions:

Although the delay in treatment was relatively short, several clinical outcomes favored earlier treatment. Along with low rates of disability and disease progression in both groups, this supports the value of treatment at CIS.

ClinicalTrials.gov identifier:

NCT01795872.

Classification of evidence:

This study provides Class IV evidence that early compared to delayed treatment prolongs time to CDMS in CIS after 11 years.

Reports of patients and relatives from the CogniCIS study about cognition in clinically isolated syndrome: what are our patients telling us?

OBJECTIVE

To assess the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) in patients with clinically isolated syndrome (CIS).

METHODS

130 European CIS patients and 60 relatives completed the MSNQ.

RESULTS

The mean (SD) MSNQ score for CIS patients was 15.5 (10.8) and for their informants 11.3 (9.6). Neither the CIS patient nor relative MSNQ report scores correlated with any of the cognitive test scores in the Brief Repeatable Battery of Neuropsychological Tests, but they were significantly related to psychosocial scales including depression.

CONCLUSIONS

In CIS, patient and relative MSNQ scores are influenced by psychosocial variables rather than actual objective cognitive status. Formal cognitive test assessment is recommended for CIS patients.

Disability and quality of life in Charcot-Marie-Tooth disease type 1

OBJECTIVES

Charcot-Marie-Tooth disease type I (CMT1) is a hereditary sensorimotor neuropathy causing variable degrees of handicap. The risk for relevant disability in respect to genetic counselling is unknown. An attempt was made to define it.

METHODS

Disability and ambulation of 50 patients with CMT1 were scored by the Hauser ambulation index score and the Rankin scale. Rankin score 2 was subdivided into 2a (independent without relevant slowness) and 2b (independent, though at the cost of excessive time consumption). The sickness impact profile was assessed and compared with patients 6 months after stroke who were without mental deficit. To define at which degree sickness and disability become relevant for genetic counselling, the patients were asked whether they would refrain from childbearing if the children were at risk of inheriting a disease that caused as much disability as they experienced themselves.

RESULTS

Subdivision of Rankin score 2 was reliable and improved validity. High disability significantly predicted an attitude against childbearing (stepwise logistic regression) only with this subdivision. Thirty six per cent of the patients voted against childbearing. The cut off for relevant disability in respect to childbearing was a Rankin score higher than 2a, which was present in 44% of the patients. Psychosocial impact was comparable with patients with stroke and similar disability. Depression was present in 18% of the patients.

CONCLUSION

Subdivision of Rankin score 2 is recommended for the assessment of longstanding disability in neuromuscular disorders. Disability becomes relevant for the attitude towards childbearing as soon as everyday activities become markedly slow (Rankin score 2b). Relevant disability occurred in 44% of the patients. Emotional stress in CMT is similar to that of patients with stroke and comparable disability.

Sensitivity and specificity of different conduction block criteria

OBJECTIVES

To resolve the discrepancy between conduction block criteria derived from healthy controls and stricter criteria suggested by computer simulation of interphase cancellation through altered motor units.

METHODS

An EMG database provided control nerves from patients with amyotrophic lateral sclerosis (ALS) or neural muscular atrophy (CMT1) (disease controls) and from subjects without neuromuscular diseases (healthy controls). We estimated normal limits from the healthy controls (criterion A) and from the pooled sample of healthy and disease controls (criterion B). We compared their sensitivity with that of an arbitrary limit of 0.5 (criterion C) in acute (AIDP) and chronic inflammatory demyelinating neuropathy (CIDP) and in multifocal motor neuropathy (MMNP). Specificity was assessed in ALS and CMT1.

RESULTS

Limits estimated from healthy controls (criterion A: amplitude ratio of <0.7 in median and peroneal nerves and <0.8 in the ulnar nerve) gave false positive results in 17.3% of the ALS nerves. High scatter of the amplitude ratio of the nerves with distal response amplitudes below 1 mV required amplitude-dependent limits (0.36 for distal responses below 1 mV, 0.56 between 1 and 2 mV, and between 0.67 and 0.73 for higher response amplitudes) for criterion B. It was false positive in 4.3% of the ALS nerves and in 28.3% of the CMT1 nerves. A limit of 0.5 for nerves with distal responses above 1 mV and a limit of 0.36 for smaller responses (criterion D) avoided false positive results in ALS without further impairing sensitivity per patient in MMNP. Sensitivity in AIDP was 34.9% for criterion A, 19.5% for criterion B, and 10.2% for criterion D. Amplitude ratios were more sensitive than area ratios in CIDP and MMNP, but less specific in CMT1.

CONCLUSIONS

Limits derived from healthy controls are unspecific in chronic neuromuscular diseases and in nerves with low response amplitudes. Criterion D should be used if motor unit restructuring or conduction delays have to be taken into account. Criterion A may be applicable in early AIDP if the distal response amplitude is above 1 mV.

Clinical and molecular genetic spectrum of autosomal dominant Emery-Dreifuss muscular dystrophy due to mutations of the lamin A/C gene

Emery-Dreifuss muscular dystrophy (EDMD) is characterized by early contractures of the elbows and Achilles tendons, slowly progressive muscle wasting and weakness, and life-threatening cardiomyopathy with conduction blocks. We recently identified LMNA encoding two nuclear envelope proteins, lamins A and C, to be implicated in the autosomal dominant form of EDMD. Here, we report on the variability of the phenotype and spectrum of LMNA mutations in 53 autosomal dominant EDMD patients (36 members of 6 families and 17 sporadic cases). Twelve of the 53 patients showed cardiac involvement exclusively, although the remaining 41 all showed muscle weakness and contractures. We were able to identify a common phenotype among the patients with skeletal muscle involvement, consisting of humeroperoneal wasting and weakness, scapular winging, rigidity of the spine, and elbow and Achilles tendon contractures. The disease course was generally slow, but we observed either a milder phenotype characterized by late onset and a mild degree of weakness and contractures or a more severe phenotype with early presentation and a rapidly progressive course in a few cases. Mutation analysis identified 18 mutations in LMNA (i.e., 1 nonsense mutation, 2 deletions of a codon, and 15 missense mutations). All the mutations were distributed between exons 1 and 9 in the region of LMNA that is common to lamins A and C. LMNA mutations arose de novo in 76% of the cases; 2 of these de novo mutations were typical hot spots, and 2 others were identified in 2 unrelated cases. There was no clear correlation between the phenotype and type or localization of the mutations within the gene. Moreover, a marked inter- and intra-familial variability in the clinical expression of LMNA mutations exists, ranging from patients expressing the full clinical picture of EDMD to those characterized only by cardiac involvement, which points toward a significant role of possible modifier genes in the course of this disease. In conclusion, the high proportion of de novo mutations together with the large spectrum of both LMNA mutations and the expression of the disease should now prompt screening for LMNA in familial and sporadic cases of both EDMD and dilated cardiomyopathy associated with conduction system disease.

Molecular diagnosis of McArdle disease: revised genomic structure of the myophosphorylase gene and identification of a novel mutation

McArdle disease is a rare autosomal recessive disorder of the muscle glycogen metabolism caused by mutations in the muscle glycogen phosphorylase gene. Until now, a total number of 11 different mutations in the coding region or splice sites of the myophosphorylase gene have been identified. In contrast to a wealth of data on the RNA and protein level, little information is available on the genomic sequence of the corresponding gene. To facilitate molecular diagnosis of McArdle disease, we reinvestigated the genomic structure of the myophosphorylase gene and sequenced about 9.8 kilobases (kb) on the genomic level. By choosing 14 intronic primer pairs, we were able to amplify the complete human coding sequence as well as the adjacent splice sites of the 20 exons. Direct sequencing of the amplification products of a consanguineous Turkish family with typical McArdle disease revealed a novel single base pair deletion in exon 18, which predicts a frameshift and a premature termination of the protein. In summary, we established a system for molecular diagnosis of McArdle disease based on a revised genomic structure of the myophosphorylase gene and demonstrated its feasibility by identification of a novel mutation.

Prominent sensory ataxia in Guillain-Barré syndrome associated with IgG anti-GD1b antibody

Sensitization with GD1b has been shown to cause sensory neuropathy in rabbit. A patient with chronic sensory-dominant polyneuropathy who had IgM antibody specifically to GD1b has been reported previously. This report describes the first patient with acute demyelinating polyneuropathy with prominent sensory symptoms who had a high titer of serum IgG anti-GD1b antibody. The serum reacted with neither GM1 nor with other b-series gangliosides (GD2, GD3, GT1b and GQ1b). Improvement in symptoms was coincident with decrease in IgG anti-GD1b antibody titer after plasmapheresis. This case supports the experimental results in rabbit suggesting that anti-GD1b antibody functions in the development of sensory ataxia.

Missense mutation (R15W) of the connexin32 gene in a family with X chromosomal Charcot-Marie-Tooth neuropathy with only female family members affected

A small family with sensorimotor neuropathy of dominant inheritance was examined. All three affected members were female. They had unusually severe symptoms and pronounced reduction of motor nerve conduction velocities with absent sensory nerve action potentials. Molecular genetic analysis disclosed a missense mutation in the connexin32 gene in codon 15 (Arg15Trp) which predicts the replacement of a basic amino acid to a non-polar amino acid in the first cytoplasmic loop of the protein. This report illustrates that in small pedigrees in which only women are affected, and which show a severe clinical phenotype, X chromosomal Charcot-Marie-Tooth neuropathy should be considered as differential diagnosis.

[Type I Charcot-Marie-Tooth syndrome. Disability and management]

Molecular genetic research on Charcot-Marie-Tooth 1 syndrome (CMT 1) progresses rapidly, still obviously no cure is available for affected individuals. Our aim was to investigate current management in clinical CMT 1 50 patients with Charcot-Marie-Tooth syndrome type I (CMT 1) were explored for applied means of therapy and use of health care institutions. We documented the number of annual appointments at a neurologist, orthopaedist and psychologist. Previous admissions to hospitals and rehabilitation centres and surgical procedures were assessed. Practice of physiotherapy, occupational and physical therapy were investigated, also administered orthopaedic devices, mechanical devices and technical modification of car and home. Drugs prescribed were listed and the number of patients seeking advice at para-medical institutions was determined. Degree of medical support did not correlate with severity of disease. We observed that persons with marked disability did not uniformly receive adequate therapy. This was partly due to the responsible physicians, and partly due to lacking cooperation of the patients. Support of affected individuals and counselling to our opinion are to be improved. This would require further evaluation of therapies, establishment and distribution of guidelines, as well as motivation of patients, which might be facilitated by the offer of molecular genetic diagnostics.