The effect of caregiving on women in families with Duchenne/Becker muscular dystrophy

Duchenne/Becker muscular dystrophy (DBMD) is a disorder of progressive muscle weakness that causes an increasing need for assistance with activities of daily living. Our objective was to assess the psychosocial health and contributing factors among female caregivers in families with DBMD. We conducted a survey of adult women among families with DBMD in the United States (US) from June 2006 through January 2007, collecting data related to the care recipient, perception of caregiving demands, personal factors, and socio‐ecologic factors. Life satisfaction, stress, and distress were assessed as outcomes. Existing validated instruments were used when available. We received responses from 1238 women who were caring for someone with DBMD, 24.2% of whom were caring for two or more people with DBMD. Caregivers were more likely to be married/cohabitating than women in the general US population, and a high level of resiliency was reported by 89.3% of caregivers. However, the rate of serious psychological distress was significantly higher among caregivers than among the general population. Likewise, 46.4% reported a high level of stress, and only 61.7% reported that they were satisfied with their life. A high level of caregiving demands based on the Zarit Burden Interview (ZBI) was reported by 50.4% of caregivers. The post‐ambulatory phase of DBMD was associated with decreased social support and increased ZBI scores. In multivariate logistic regression modelling, life satisfaction was dependent on high social support, high resiliency, high income, and form of DBMD. Distress and high stress were predicted by low resiliency, low social support, and low income. Employment outside of the home was also a predictor of high stress. Interventions focused on resiliency and social support are likely to improve the quality of life of DBMD caregivers, and perhaps caregivers of children with other disabilities or special health care needs as well.     

MLPA技术在假肥大型肌营养不良症基因检测和产前诊断中的应用

目的 评价多重连接依赖式探针扩增 (Multiplex ligation-dependent probe amplification,MLPA) 技术对假肥大型肌营养不良症(DMD)患者进行基因诊断和产前诊断的应用价值。方法 应用MLPA技术对具有典型表型的22例患者进行DMD基因79个外显子拷贝数变异(缺失/重复突变)检测,同时对部分家系中孕妇携带者进行产前诊断,STR毛细管电泳连锁分析方法进行辅助诊断及验证。结果 22例患者中15例为缺失突变,4例为重复突变,3例未见拷贝数变异。14例MLPA检测结果为阳性的患者母亲中有9例为携带者。产前诊断的7例胎儿中,3例为女性胎儿携带者,3例男性正常胎儿和1例女性正常胎儿。结论 MLPA技术能准确、快速、可靠地检测DMD基因拷贝数变异(缺失或重复突变)。     

Family function in families of children with Duchenne muscular dystrophy

This article investigates the relationships of child- and family-related variables with family function in families with children who have Duchenne muscular dystrophy. Child-related variables included level of disability (indicator: Barthel Index) and age at diagnosis. Family-related variables included caregiver health status (indicator: Duke Health Profile), family income and employment, family support (indicator: Family APGAR), family hardiness (indicator: Family Hardiness Index), and family functioning (indicator: Family Assessment Device). Family function displayed a significant correlation with age at diagnosis, but not with disability level. It was also significantly correlated with family hardiness, caregiver health status, and levels of family support, but not with income or employment variables. These findings highlight the need to assist families to cope with the presence of serious illness in their children.     

From gene to disease; the dystrophin gene involved in Duchenne and Becker muscular dystrophy

Duchenne and Becker muscular dystrophy (DMD and BMD) are progressive disorders, which almost exclusively affect males. DMD is the more severe type with an onset at 2-3 years of age. Patients become wheelchair-bound before the age of 13 and often die due to cardiac arrest or respiratory insufficiency. BMD, a more varying phenotype which may overlap with limb girdle muscular dystrophy (LGMD), has a less severe muscle weakness which starts later than in DMD patients. DMD carriers may show some muscle weakness. The dystrophin gene (2.4 Mb), known to be involved in DMD/BMD, codes for a 427 kilodalton muscle-specific protein named dystrophin as well as several tissue-specific isoforms. Dystrophin, as part of a membrane-bound complex of proteins, connects the cytoskeleton of the muscle cell to the extracellular matrix. Since 1985, when highly reliable carrier detection and prenatal diagnosis at the DNA level became possible, over 250 prenatal tests have been performed. Molecular genetic analysis, highlighted a phenomenon called germinal mosaicism, which explains the recurrence of de novo mutations and led to the discovery of the so-called reading-frame rule, which helps to discriminate between DMD and BMD. Fifteen years after the discovery of the dystrophin gene, mutations can be detected in 95% of the patients, while the remaining 5% are still hiding within this very large gene.     

A review of nutrition in Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a recessive X linked genetic disorder characterised by progressive muscle weakness and reduced muscle tone. Affecting only boys, it limits life expectancy to approximately 20 years. A literature review was conducted using MEDLINE and the Cochrane Library, employing the term 'Duchenne muscular dystrophy'. A total of 1491 articles in English were recovered. These papers were searched thematically under the headings: body composition ( n  = 10), energy expenditure ( n  = 10), nutrition ( n  = 6), corticosteroid therapy ( n  = 55) and gene therapy ( n  = 199). Key dietetic practice points were identified relevant to nutritional management. Papers supporting these key themes were assigned a level of evidence and grade of recommendation. There is limited high-quality evidence to guide the nutritional management of boys with DMD. Currently, the majority of evidence is based on expert opinion and clinical expertise. Delayed growth, short stature, muscle wasting and increased fat mass are characteristics of DMD and impact on nutritional status and energy requirements. The early introduction of steroids has altered the natural history of the disease, but can exacerbate weight gain in a population already susceptible to obesity. Prior to commencing steroids, anticipatory guidance for weight management should be provided. Malnutrition is a feature of end stage disease requiring a multidisciplinary approach, such as texture modification and supplemental feeding. Micronutrient requirements are yet to be determined but, as a result of corticosteroid treatment, vitamin D and calcium should be supplemented. Some evidence exists supporting supplementation with creatine monohydrate to improve muscle strength. More research is needed to provide a higher quality of evidence for dietitians working within this area.     

Genetic epidemiology of Duchenne muscular dystrophy in Japan: classical segregation analysis

Classical segregation analysis was performed on 651 male probands in 597 families with Duchenne muscular dystrophy (DMD) collected from 20 of 25 National Institutions for Muscle Diseases in Japan. The proportion of sporadic cases is compatible with 1/3 expected for an X-linked lethal trait with an equal mutation rate in egg and sperm, the estimated mutation rates being 9.2 X 10(-5) and 10.9 X 10(-5)/gamete/generation, respectively. The incidence and prevalence among males were estimated to be 29.2 X 10(-5) and 6.7 X 10(-5), respectively. These results indicated no difference from the patterns of DMD in Western countries.     

Duchenne型肌营养不良症的临床特点和基因分析

目的探讨Duchenne型肌营养不良症(DMD)的临床特点和基因特点,为临床诊断提供依据。方法回顾性分析2015—2019年中山大学附属第六医院遗传代谢实验室基因检测确诊的15例DMD患儿的基因检测结果和临床资料,探讨DMD的临床特征和基因特点。结果 15例患儿发病年龄1个月～12岁,临床表现以小腿腓肠肌假性肥大、Gowers征及走路摇摆(鸭步)为主,AST、ALT、CK、CK-MB及肌红蛋白等肌酶水平均明显升高。通过组合的高通量检测技术等检查DMD基因情况,结果多为缺失突变,共12例(80.0%),其中大片重复缺失突变10例(66.7%),点突变2例(13.3%);错义突变1例(6.6%);插入突变1例(6.6%);无义突变1例(6.6%)。其中7例(46.7%)患儿母亲进行了相关基因检测,4例患儿母亲为该基因突变点携带者。而根据ACMG变异类型,15例患儿中13例(86.7%)为致病突变,2例(13.3%)为疑似致病突变。同时15例病例中有2例暂无相关文献报道过。所有的突变可发生在基因的任何位置,但缺失的热点区域位于基因的中央区外显子45～55区共8例,占缺失突变的53.3%。结论...     

Body composition and energy expenditure in Duchenne muscular dystrophy

OBJECTIVE: To investigate the relationship between resting energy expenditure (REE) and body composition in Duchenne Muscular Dystrophy (DMD). DESIGN: An observational study. SETTING: University Research Centre. SUBJECTS: Nine Duchenne children (age range 6-12 y), mean relative weight 128%, agreed to undergo the investigation and all of them completed the study; INTERVENTIONS: Assessment of body composition (total body fat and skeletal muscle mass) by magnetic resonance imaging and resting energy expenditure by indirect calorimetry. MAIN OUTCOME MEASURES: Fat mass (FM; kg and percentage weight), fat-free mass (FFM; kg and percentage weight), muscle mass (kg and percentage weight), resting energy expenditure (kJ/kg body weight and kJ/kg fat-free mass). RESULTS:: In Duchenne children fat mass averages 32% and total skeletal muscle mass 20% of body weight. Resting energy expenditure per kg of body weight falls within the normal range for children of the same age range, while when expressed per kg of FFM is significantly higher than reference values. No relationship was found between REE and total skeletal muscle mass. CONCLUSIONS: Our results do not demonstrate a low REE in DMD boys; on the contrary REE per kg of FFM is higher than normal, probably due to the altered FFM composition. We suggest that the development of obesity in DMD children is not primarily due to a low REE but to other causes such as a reduction in physical activity and or overfeeding.     

Diagnosis of Duchenne muscular dystrophy: parents'experiences and satisfaction

The purpose of the study was to investigate parents' experiences of diagnosis of Duchenne muscular dystrophy. Data were collected retrospectively by postal questionnaire from the parents of 158 boys diagnosed at different times and locations and, for some, after lengthy periods of uncertainty. Most parents knew nothing about Duchenne before being given the diagnosis. There was considerable variation in parents' experiences but the only independent predictors of parents' satisfaction with how the diagnosis was given were obtaining the information that they wanted and feeling that they had understood and remembered it. What distinguishes Duchenne from, say, Down syndrome is that doctors are having to deliver a death sentence on a child. Our data show that this can be done in a way that is satisfactory to parents. What is required is empathy and sensitivity to parents' informational and emotional needs.     

Natural evolution of weight status in Duchenne muscular dystrophy: a retrospective audit

The life expectancy of patients with Duchenne muscular dystrophy (DMD) has increased. A cross-sectional study of DMD patients showed that 54 % of 13-year-old patients are obese and that 54 % of 18-year-old patients are underweight. We aimed to describe the natural evolution of weight status in DMD. This retrospective multi-centre audit collected body-weight measurements for seventy DMD patients born before 1992. The body-weight:age ratio (W:A) was used to evaluate weight status in reference to the Griffiths and Edwards chart. At the age of 13 years, 73 % were obese and 4 % were underweight. At maximal follow-up (age 15-26 years, mean 18·3 (sd 2·3) years), 47 % were obese and 34 % were underweight. Obesity at the age of 13 years was associated with later obesity, whereas normal weight status and underweight in 13-year-old patients predicted later underweight. A W:A ≥ 151 % in 13-year-old patients predicted later obesity, and a W:A ≤ 126·5 % predicted later underweight. Our audit provides the first longitudinal information about the spontaneous outcome of weight status in DMD. Patients (13 years old) with a W:A ≥ 151 % were more likely to become obese in late adolescence, but obesity prevented later underweight. These data suggest that mild obesity in 13-year-old DMD patients (W:A between 120 and 150 %) should not be discouraged because it prevents later underweight.     

Three novel serum biomarkers,miR-1, miR-133a,and miR-206 for Limb-girdle muscular dystrophy,Facioscapulohumeral muscular dystrophy,and Becker muscular dystrophy

Objectives

Muscular dystrophies are a clinically and genetically heterogeneous group of inherited myogenic disorders. In clinical tests for these diseases, creatine kinase (CK) is generally used as diagnostic blood-based biomarker. However, because CK levels can be altered by various other factors, such as vigorous exercise, etc., false positive is observed. Therefore, three microRNAs (miRNAs), miR-1, miR-133a, and miR-206, were previously reported as alternative biomarkers for duchenne muscular dystrophy (DMD). However, no alternative biomarkers have been established for the other muscular dystrophies.

Methods

We, therefore, evaluated whether these miR-1, miR-133a, and miR-206 can be used as powerful biomarkers using the serum from muscular dystrophy patients including DMD, myotonic dystrophy 1 (DM1), limb-girdle muscular dystrophy (LGMD), facioscapulohumeral muscular dystrophy (FSHD), becker muscular dystrophy (BMD), and distal myopathy with rimmed vacuoles (DMRV) by qualitative polymerase chain reaction (PCR) amplification assay.

Results

Statistical analysis indicated that all these miRNA levels in serum represented no significant differences between all muscle disorders examined in this study and controls by Bonferroni correction. However, some of these indicated significant differences without correction for testing multiple diseases (P < 0.05). The median values of miR-1 levels in the serum of patients with LGMD, FSHD, and BMD were approximately 5.5, 3.3 and 1.7 compared to that in controls, 0.68, respectively. Similarly, those of miR-133a and miR-206 levels in the serum of BMD patients were about 2.5 and 2.1 compared to those in controls, 1.03 and 1.32, respectively.

Conclusions

Taken together, our data demonstrate that levels of miR-1, miR-133a, and miR-206 in serum of BMD and miR-1 in sera of LGMD and FSHD patients showed no significant differences compared with those of controls by Bonferroni correction. However, the results might need increase in sample sizes to evaluate these three miRNAs as variable biomarkers.

Electronic supplementary material

The online version of this article (doi:10.1007/s12199-014-0405-7) contains supplementary material, which is available to authorized users.     

反义寡核苷酸治疗Duchenne型肌营养不良的研究进展

Duchenne型肌营养不良(DMD)是由抗肌萎缩蛋白基因Dystrophin发生移码突变导致的儿童遗传性致死性肌病。反义寡核苷酸(AON)靶向外显子中的剪接调控序列可以诱导Dystrophin基因的相应外显子跳读,以恢复dystrophin mRNA阅读框,是目前新的DMD治疗方法。该治疗方法的有效性已在患者来源的肌细胞及动物模型中得到证实。目前,AON靶向治疗DMD已经进入药物临床试验阶段。笔者拟对DMD的分子致病机制、AON治疗DMD的作用机制及其临床试验新进展进行综述,为AON在DMD治疗中的临床应用提供理论依据。     

18 years experience with mechanical ventilation in patients with Duchenne muscular dystrophy

OBJECTIVE: To find out which patients with Duchenne muscular dystrophy are eligible for starting home mechanical ventilation and what the survival rate is. DESIGN: Retrospective. METHOD: In 48 patients with Duchenne muscular dystrophy who were treated with home ventilation from 1987, the results were assessed in the follow-up visit in February 2005. Initially, ventilation was only given through a tracheotomy (TPPV), but after starting up a multidisciplinary neuromuscular consultation, non-invasive ventilation (NIPPV) was offered in an earlier stage of the disease. The following data were derived from the outpatient medical record: indication for ventilation, vital capacity (VC), arterial blood gas values, duration of ventilation up to February 2005, survival and causes of death. RESULTS: 15 patients died. The 5-year survival rate was 75% from the start of mechanical ventilation and 67% (18/27) of the patients were still living at home at the time of the follow-up visit. The most important causes of death were cardiomyopathy (5/15) and tracheal bleeding (3/15). The group of patients who started ventilation before 1995 (n = 17) had a significantly smaller VC than the group (n = 31) who started after the neuromuscular consultation was set up. The PaCO2 during daytime was significantly higher in the group that started ventilation before 1995 compared to the group that started later. CONCLUSION: Home mechanical ventilation can be implemented effectively in patients with Duchenne dystrophy, with a 5-year survival of 75%.     

Duchenne型肌营养不良症植入前遗传学诊断研究进展

植入前遗传学诊断是在胚胎着床前确定其遗传物质是否正常 ,从而决定该胚胎能否移植的一门新兴技术 ,该技术已应用于性别、单基因遗传病及染色体遗传病的诊断。目前世界上已有两百多个正常婴儿通过植入前诊断技术诞生 ,该资料回顾了DMD植入前诊断技术的发展 ,并对其技术路线及目前存在的问题及解决方法进行综述。     

Social/economic costs and health-related quality of life in patients with Duchenne muscular dystrophy in Europe

Objective

The aim of this study was to determine the economic burden from a societal perspective and the health-related quality of life (HRQOL) of patients with Duchenne muscular dystrophy (DMD) in Europe.

Methods

We conducted a cross-sectional study of patients with DMD from Bulgaria, France, Germany, Hungary, Italy, Spain, Sweden, and the UK. Data on demographic characteristics, healthcare resource utilization, informal care, labor productivity losses, and HRQOL were collected from the questionnaires completed by patients or their caregivers. HRQOL was measured with the EuroQol 5-domain (EQ-5D) questionnaire. Costs have been estimated from a societal perspective adopting a bottom-up approach.

Results

A total of 422 questionnaires were included in the study; 268 of which were collected from patients with DMD and 154 from caregivers. The average annual cost per person in 2012 ranged from €7657 in Hungary to €58,704 in France. Direct non-healthcare costs are the main component of whole costs and informal care is the main driver of non-healthcare costs. Costs are also shown to differ between children and adults. With regard to HRQOL of adult patients, the EQ-5D VAS score and EQ-5D index scores were 50.5 and 0.24, respectively. The corresponding EQ-5D VAS and EQ-5D index scores for caregivers were 74.7 and 0.71, respectively.

Conclusions

We have estimated the average annual cost per patient with DMD in eight European countries adopting a social perspective, and to our knowledge this is the first study with such a wide perspective. The results on costs show a considerable gap between Eastern and Western European countries. Non-healthcare costs range from 64 to 89 % of overall costs and informal care is to a great extent the main driver of this cost category. The HRQOL of people with DMD is much lower than that of the general population.