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Effect of the planet health intervention on eating disorder symptoms in Massachusetts middle schools, 2005-2008

Tue, 02/04/2014 - 5:20pm

INTRODUCTION: The Planet Health obesity prevention curriculum has prevented purging and abuse of diet pills (disordered weight control behavior [DWCB]) in middle-school girls in randomized trials, but the effects of Planet Health on DWCB when implemented by schools under dissemination conditions are not known.

METHODS: Massachusetts Department of Public Health and Blue Cross Blue Shield of Massachusetts disseminated Planet Health as part of the 3-year, Healthy Choices obesity prevention program in middle schools. We conducted an evaluation in 45 schools from fall 2005 to spring 2008. We gathered data from school staff to quantify intervention activities, and we gathered anonymous cross-sectional survey data from students on DWCB at baseline and Year 3 follow-up (n = 16,369). Multivariate logistic analyses with generalized estimating equations examined the effect of intervention activities on odds of students reporting DWCB at follow-up.

RESULTS: Students in schools reaching a high number of youth with Planet Health lessons on reducing television viewing had lower odds of DWCB at follow-up (odds ratio [OR], 0.80 per 100 lesson-exposures; 95% confidence interval [CI], 0.74-0.85). In addition, reduced odds of DWCB at follow-up were found in schools with active staff teamwork (OR, 0.76; 95% CI, 0.66-0.86) and the presence of programs addressing television viewing goals with staff (OR, 0.38; 95% CI, 0.28-0.53).

CONCLUSION: Combined evidence from efficacy and effectiveness trials and now from dissemination research indicates that appropriately designed obesity prevention programs can achieve DWCB prevention on a large scale.

Using qualitative methods to design a culturally appropriate child feeding questionnaire for low-income, Latina mothers

Tue, 02/04/2014 - 5:20pm

Obesity rates remain high among children in the United States (US), but children of low-income, minority families are at particularly high risk. Latinos are the largest and most rapidly growing US population group. Effective strategies will require attention to a wide array of culturally mediated variables that influence child feeding practices through the social contexts in which behaviors take place. This paper presents the design and implementation of a qualitative study examining low-income, Latina mothers' perceptions of child weight status and feeding practices, and their associations with the development of overweight in children. Guided by the social ecologic model and social contextual model on the role of the family in mediating health behavior, the Latina Mother Child Feeding Practices (LMCFP) study provided a systematic exploration of the influence of social class, culture, and environmental factors associated with mothers' perceptions of child overweight on feeding practices and behaviors. The design for this qualitative study consisted of three sequential phases: focus groups, in-depth interviews and cognitive interviews with Latina mothers conducted by Spanish-speaking researchers. Results showed the important role of socio-cultural factors in influencing Latina mothers' child feeding practices. In the short-term, this research yielded information to develop a child-feeding questionnaire appropriate for low-income, Latina mothers. Findings have important implications in developing nutrition education strategies for child health promotion that account for the social and cultural context of minority, low-income caregivers.

Facioscapulohumeral Muscular Dystrophy: Unraveling the Mysteries of a Complex Epigenetic Disease

Mon, 02/03/2014 - 5:10pm

Facioscapulohumeral muscular dystrophy (FSHD) is the third most common inherited neuromuscular disease, with an epigenetic basis linked to contractions or hypomethylation of the chromosome 4q subtelomere. Efforts to understand chromatin alterations in this region have yielded several interesting models of the disorder. This chapter summarizes the genetic and epigenetic etiology of FSHD and the search for candidate genes, with an emphasis on recent discoveries. It also seeks to highlight current therapeutic strategies and future directions for the field. In particular, there is a need for large, well-controlled studies to identify consistent biomarkers of early disease pathology.

The Handbook of Health Behavior Change

Mon, 02/03/2014 - 11:40am

Provides a comprehensive overview of behavior change as it relates to public health.

Addressing Tobacco Use and Dependence

Mon, 02/03/2014 - 11:40am

Objectives of this chapter: Understand the prevalence of tobacco use and cessation; Identify the biological, psychological, and social factors that influence tobacco use and dependence; Describe intervention approaches that can be used to help people change tobacco use behavior.

Smoking frequency among current college student smokers: distinguishing characteristics and factors related to readiness to quit smoking

Fri, 01/31/2014 - 4:36pm

Given the increased prevalence of non-daily smoking and changes in smoking patterns, particularly among young adults, we examined correlates of smoking level, specifically motives for smoking, and readiness to quit smoking among 2682 college undergraduates who completed an online survey. Overall, 64.7% (n = 1736) were non-smokers, 11.6% (n = 312) smoked 1-5 days, 10.5% (n = 281) smoked 6-29 days and 13.2% (n = 353) were daily smokers. Ordinal regression analyses modeling smoking level indicated that correlates of higher smoking level included having more friends who smoke (beta = 0.63, 95% CI 0.57-0.69) and more frequent other tobacco use (beta = 0.04, 95% CI 0.02-0.05), drinking (beta = 0.04, 95% CI 0.02-0.07) and binge drinking (beta = 0.09, 95% CI 0.06-0.13). Bivariate analyses indicated that daily smokers (versus the subgroups of non-daily smokers) were less likely to smoke for social reasons but more likely to smoke for self-confidence, boredom, and affect regulation. Controlling for sociodemographics, correlates of readiness to quit among current smokers included fewer friends who smoke (P = 0.002), less frequent binge drinking (P = 0.03), being a social smoker (P < 0.001), smoking less for self-confidence (P = 0.04), smoking more for boredom (P = 0.03) and less frequent smoking (P = 0.001). Specific motives for smoking and potential barriers to cessation particularly may be relevant to different groups of college student smokers.

Tobacco dependence treatment teaching by medical school clerkship preceptors: survey responses from more than 1,000 US medical students

Fri, 01/31/2014 - 4:36pm

OBJECTIVE: To determine factors associated with tobacco cessation counseling in medical school clerkships.

METHODS: Third-year medical students at 10 medical schools across the United States completed a 100-item survey, measuring the frequency with which they experienced their preceptors providing clinical teaching components: clear instruction, feedback, modeling behavior, setting clear objectives, and responding to questions about tobacco dependence counseling as well as frequency of use of tobacco prompts and office systems. Our primary dependent measure was student self-reported skill level for items of tobacco dependence treatment (e.g. "5As").

RESULTS: Surveys were completed by 1213 students. For both family medicine and internal medicine clerkships, modeling and providing clear instruction on ways to provide tobacco counseling were reported most commonly. In contrast, providing feedback and clear objectives for tobacco dependence treatment lagged behind. Overall, students who reported preceptors' provision of optimal clinical teaching components and office system prompts in both family medicine and internal medicine clerkships had higher self-reported skill (P<0.001) than students with no exposure or exposure during only one of the clerkships.

CONCLUSIONS: Future educational interventions intended to help students adopt effective tobacco dependence treatment techniques should be engineered to facilitate these critical precepting components.

Smokeless tobacco products sold in Massachusetts from 2003 to 2012: trends and variations in brand availability, nicotine contents and design features

Fri, 01/31/2014 - 4:36pm

BACKGROUND: Sales of smokeless tobacco products have increased in the USA. More than one in eight males in the 12th grade are current users of smokeless tobacco. Surveillance data examining nicotine levels of smokeless tobacco subsequent to 2006 have not been reported in the literature.

METHODS: Data on nicotine levels and design features (eg, pH, moisture content, leaf cut and flavour) of smokeless tobacco products sold in Massachusetts were obtained from manufacturers between 2003 and 2012. Design features, levels and temporal trends in unionised (free) nicotine and nicotine content of smokeless tobacco products were analysed overall and by manufacturer and product type.

RESULTS: The annual total number of moist snuff products increased from 99 in 2003 to 127 in 2012. The annual total number of reported snus products increased from 4 in 2003 to the highest level of 62 in 2011, before decreasing to 26 in 2012. Overall, mean unionised (free) nicotine remained relatively stable (beta=0.018 (95% CI -0.014 to 0.050) mg/g dry weight/year) from 2003 to 2012. However, both levels and temporal trends of mean free nicotine varied significantly among manufacturers (p<0.001). Since 2003, the free nicotine content of snus has increased at an overall rate of 0.192 (95% CI 0.138 to 0.246) mg/g dry weight/year, but varied by manufacturer (p<0.001).

CONCLUSIONS: The number of smokeless tobacco products increased in the Massachusetts market. Further, mean unionised (free) nicotine levels in smokeless tobacco products of several manufacturers continued to rise despite decreasing levels from other manufacturers. The current success in tobacco control is very likely undermined without government surveillance, regulation and widespread public disclosure of nicotine levels in these products.

Cotinine and Tobacco-Specific Carcinogen Exposure Among Nondaily Smokers in a Multiethnic Sample

Fri, 01/31/2014 - 4:36pm

BACKGROUND: Nondaily smoking has increased among current U.S. smokers in the past decade and is practiced by a significant percentage of smokers. Although research in nondaily smoking has grown, little is known about levels of exposure to tobacco toxicants among nondaily smokers and their variation across ethnic groups.

METHODS: We examined urinary levels of cotinine and a tobacco-specific nitrosamine (NNAL) in community participants. Associations between the biomarker data and smoking characteristics were evaluated using Spearman's correlation analysis.

RESULTS: Participants were 28 Blacks, 4 Latinos, and 25 Whites who smoked at least 1 cigarette on 4-24 days in the past 30 days. Participants averaged 3.3 (SD = 2.1) cigarettes per day (cpd) on days smoked, smoked an average of 13.0 (SD = 5.4) days in the past month, and smoked nondaily for 10.5 (SD = 10.5) years. Median levels of creatinine-normalized cotinine and NNAL were 490.9ng/mg and 140.7 pg/mg, respectively. NNAL and cotinine were highly correlated, r = .84; NNAL and cotinine were modestly correlated with cpd, r = .39 and r = .34 (all p values <.05). The number of days smoked per month was not associated with any biomarker levels.

CONCLUSIONS: Our findings demonstrate that nondaily smokers are, on average, exposed to significant levels of nicotine and carcinogenic nitrosamines, with exposures of 40%-50% of those seen in daily smokers. This level of exposure suggests a significant health risk. Nicotine and carcinogen exposure is most closely related to number of cigarettes smoked per day but not to number of days per month of smoking.

Pei-Pei Lei on Using InfoPath as a Project Management/Data Collection Tool

Thu, 01/30/2014 - 12:45pm

Blog post to AEA365, a blog sponsored by the American Evaluation Association (AEA) dedicated to highlighting Hot Tips, Cool Tricks, Rad Resources, and Lessons Learned for evaluators. The American Evaluation Association is an international professional association of evaluators devoted to the application and exploration of program evaluation, personnel evaluation, technology, and many other forms of evaluation. Evaluation involves assessing the strengths and weaknesses of programs, policies, personnel, products, and organizations to improve their effectiveness.

Health Information Literacy Outreach: A Curriculum for Improving Health Information Literacy of 6th Grade Children

Wed, 01/29/2014 - 2:35pm

This health information literacy (HIL) curriculum is designed for sixth grade students. It was developed by librarian and faculty from MCPHS University in collaboration with a local public library, art museum, local department of public health and local public elementary schools. It is designed around a major environmental health problem in the U.S., childhood lead poisoning.

The curriculum is designed to: 1) improve the health information literacy skills, and 2) increase knowledge of lead poisoning. A secondary goal of the project is to encourage 6th grade students to include attending college as one of their aspirations.

The curriculum is highly interactive and designed to be utilized over three to five sessions. A detailed description of the program components can be found in the following paper: Bond I, Friel C, Lahoz M. Spearheading Health Information Literacy in the Community: The Libraries as Leaders, IFLA Congress, June 04, 2011. Available at:

Materials in this curriculum packet include: a pre and post-test to evaluate the effectiveness of the program, laboratory “experiments” to be conducted in the classroom or college laboratory, worksheets to guide students as they evaluate health information websites, non-fiction stories to read to students about lead poisoning cases, and a poster template for students to use to design a capstone poster. The curriculum also includes fictional Medical Mystery cases that contain artwork specific to the Worcester Art Museum. These cases could be adapted to include works of art from any partnering art museum.

This curriculum can be modified and used by librarians, teachers, public health workers, museum staff and anyone interested in conducting an HIL outreach project. The project was funded by the National Network of Libraries of Medicine-New England Region.

Transcriptional regulation differs in affected facioscapulohumeral muscular dystrophy patients compared to asymptomatic related carriers

Tue, 01/28/2014 - 4:40pm

Facioscapulohumeral muscular dystrophy (FSHD) is a progressive muscle disorder that has been associated with a contraction of 3.3-kb repeats on chromosome 4q35. FSHD is characterized by a wide clinical inter- and intrafamilial variability, ranging from wheelchair-bound patients to asymptomatic carriers. Our study is unique in comparing the gene expression profiles from related affected, asymptomatic carrier, and control individuals. Our results suggest that the expression of genes on chromosome 4q is altered in affected and asymptomatic individuals. Remarkably, the changes seen in asymptomatic samples are largely in products of genes encoding several chemokines, whereas the changes seen in affected samples are largely in genes governing the synthesis of GPI-linked proteins and histone acetylation. Besides this, the affected patient and related asymptomatic carrier share the 4qA161 haplotype. Thus, these polymorphisms by themselves do not explain the pathogenicity of the contracted allele. Interestingly, our results also suggest that the miRNAs might mediate the regulatory network in FSHD. Together, our results support the previous evidence that FSHD may be caused by transcriptional dysregulation of multiple genes, in cis and in trans, and suggest some factors potentially important for FSHD pathogenesis. The study of the gene expression profiles from asymptomatic carriers and related affected patients is a unique approach to try to enhance our understanding of the missing link between the contraction in D4Z4 repeats and muscle disease, while minimizing the effects of differences resulting from genetic background.

Ku70 regulates Bax-mediated pathogenesis in laminin-alpha2-deficient human muscle cells and mouse models of congenital muscular dystrophy

Tue, 01/28/2014 - 4:40pm

The severely debilitating disease Congenital Muscular Dystrophy Type 1A (MDC1A) is caused by mutations in the gene encoding laminin-alpha2. Bax-mediated muscle cell death is a significant contributor to the severe neuromuscular pathology seen in the Lama2-null mouse model of MDC1A. To extend our understanding of pathogenesis due to laminin-alpha2-deficiency, we have now analyzed molecular mechanisms of Bax regulation in normal and laminin-alpha2-deficient muscles and cells, including myogenic cells obtained from patients with a clinical diagnosis of MDC1A. In mouse myogenic cells, we found that, as in non-muscle cells, Bax co-immunoprecipitated with the multifunctional protein Ku70. In addition, cell permeable pentapeptides designed from Ku70, termed Bax-inhibiting peptides (BIPs), inhibited staurosporine-induced Bax translocation and cell death in mouse myogenic cells. We also found that acetylation of Ku70, which can inhibit binding to Bax and can be an indicator of increased susceptibility to cell death, was more abundant in Lama2-null than in normal mouse muscles. Furthermore, myotubes formed in culture from human laminin-alpha2-deficient patient myoblasts produced high levels of activated caspase-3 when grown on poly-L-lysine, but not when grown on a laminin-alpha2-containing substrate or when treated with BIPs. Finally, cytoplasmic Ku70 in human laminin-alpha2-deficient myotubes was both reduced in amount and more highly acetylated than in normal myotubes. Increased susceptibility to cell death thus appears to be an intrinsic property of human laminin-alpha2-deficient myotubes. These results identify Ku70 as a regulator of Bax-mediated pathogenesis and a therapeutic target in laminin-alpha2-deficiency.

Establishment of clonal myogenic cell lines from severely affected dystrophic muscles - CDK4 maintains the myogenic population

Tue, 01/28/2014 - 4:40pm

BACKGROUND: A hallmark of muscular dystrophies is the replacement of muscle by connective tissue. Muscle biopsies from patients severely affected with facioscapulohumeral muscular dystrophy (FSHD) may contain few myogenic cells. Because the chromosomal contraction at 4q35 linked to FSHD is thought to cause a defect within myogenic cells, it is important to study this particular cell type, rather than the fibroblasts and adipocytes of the endomysial fibrosis, to understand the mechanism leading to myopathy.

RESULTS: We present a protocol to establish clonal myogenic cell lines from even severely dystrophic muscle that has been replaced mostly by fat, using overexpression of CDK4 and the catalytic component of telomerase (human telomerase reverse transcriptase; hTERT), and a subsequent cloning step. hTERT is necessary to compensate for telomere loss during in vitro cultivation, while CDK4 prevents a telomere-independent growth arrest affecting CD56+ myogenic cells, but not their CD56- counterpart, in vitro.

CONCLUSIONS: These immortal cell lines are valuable tools to reproducibly study the effect of the FSHD mutation within myoblasts isolated from muscles that have been severely affected by the disease, without the confounding influence of variable amounts of contaminating connective-tissue cells.

Gene expression profiling of skeletal muscles treated with a soluble activin type IIB receptor

Tue, 01/28/2014 - 4:40pm

Inhibition of the myostatin signaling pathway is emerging as a promising therapeutic means to treat muscle wasting and degenerative disorders. Activin type IIB receptor (ActRIIB) is the putative myostatin receptor, and a soluble activin receptor (ActRIIB-Fc) has been demonstrated to potently inhibit a subset of transforming growth factor (TGF)-beta family members including myostatin. To determine reliable and valid biomarkers for ActRIIB-Fc treatment, we assessed gene expression profiles for quadriceps muscles from mice treated with ActRIIB-Fc compared with mice genetically lacking myostatin and control mice. Expression of 134 genes was significantly altered in mice treated with ActRIIB-Fc over a 2-wk period relative to control mice (fold change > 1.5, P < 0.001), whereas the number of significantly altered genes in mice treated for 2 days was 38, demonstrating a time-dependent response to ActRIIB-Fc in overall muscle gene expression. The number of significantly altered genes in Mstn(-/-) mice relative to control mice was substantially higher (360), but for most of these genes the expression levels in the 2-wk treated mice were closer to the levels in the Mstn(-/-) mice than in control mice (P < 10(-)(3)(0)). Expression levels of 30 selected genes were further validated with quantitative real-time polymerase chain reaction (qPCR), and a correlation of >/= 0.89 was observed between the fold changes from the microarray analysis and the qPCR analysis. These data suggest that treatment with ActRIIB-Fc results in overlapping but distinct gene expression signatures compared with myostatin genetic mutation. Differentially expressed genes identified in this study can be used as potential biomarkers for ActRIIB-Fc treatment, which is currently in clinical trials as a therapeutic agent for muscle wasting and degenerative disorders.

Peripheral nerve pathology, including aberrant Schwann cell differentiation, is ameliorated by doxycycline in a laminin-alpha2-deficient mouse model of congenital muscular dystrophy

Tue, 01/28/2014 - 4:40pm

The most common form of childhood congenital muscular dystrophy, Type 1A (MDC1A), is caused by mutations in the human LAMA2 gene that encodes the laminin-alpha2 subunit. In addition to skeletal muscle deficits, MDC1A patients typically show a loss of peripheral nerve function. To identify the mechanisms underlying this loss of nerve function, we have examined pathology and cell differentiation in sciatic nerves and ventral roots of the laminin-alpha2-deficient (Lama2(-/-)) mice, which are models for MDC1A. We found that, compared with wild-type, sciatic nerves of Lama2(-/-) mice had a significant increase in both proliferating (Ki67+) cells and premyelinating (Oct6+) Schwann cells, but also had a significant decrease in both immature/non-myelinating [glial fibrillary acidic protein (GFAP)(+)] and myelinating (Krox20+) Schwann cells. To extend our previous work in which we found that doxycycline, which has multiple effects on mammalian cells, improves motor behavior and more than doubles the median life-span of Lama2(-/-) mice, we also determined how nerve pathology was affected by doxycycline treatment. We found that myelinating (Krox20+) Schwann cells were significantly increased in doxycycline-treated compared with untreated sciatic nerves. In addition, doxycycline-treated peripheral nerves had significantly less pathology as measured by assays such as amount of unmyelinated or disorganized axons. This study thus identified aberrant proliferation and differentiation of Schwann cells as key components of pathogenesis in peripheral nerves and provided proof-of-concept that pharmaceutical therapy can be of potential benefit for peripheral nerve dysfunction in MDC1A.

Large-scale population analysis challenges the current criteria for the molecular diagnosis of fascioscapulohumeral muscular dystrophy

Tue, 01/28/2014 - 4:40pm

Facioscapulohumeral muscular dystrophy (FSHD) is a common hereditary myopathy causally linked to reduced numbers (≤8) of 3.3 kilobase D4Z4 tandem repeats at 4q35. However, because individuals carrying D4Z4-reduced alleles and no FSHD and patients with FSHD and no short allele have been observed, additional markers have been proposed to support an FSHD molecular diagnosis. In particular a reduction in the number of D4Z4 elements combined with the 4A(159/161/168)PAS haplotype (which provides the possibility of expressing DUX4) is currently used as the genetic signature uniquely associated with FSHD. Here, we analyzed these DNA elements in more than 800 Italian and Brazilian samples of normal individuals unrelated to any FSHD patients. We find that 3% of healthy subjects carry alleles with a reduced number (4-8) of D4Z4 repeats on chromosome 4q and that one-third of these alleles, 1.3%, occur in combination with the 4A161PAS haplotype. We also systematically characterized the 4q35 haplotype in 253 unrelated FSHD patients. We find that only 127 of them (50.1%) carry alleles with 1-8 D4Z4 repeats associated with 4A161PAS, whereas the remaining FSHD probands carry different haplotypes or alleles with a greater number of D4Z4 repeats. The present study shows that the current genetic signature of FSHD is a common polymorphism and that only half of FSHD probands carry this molecular signature. Our results suggest that the genetic basis of FSHD, which is remarkably heterogeneous, should be revisited, because this has important implications for genetic counseling and prenatal diagnosis of at-risk families.

Optimization of large gel 2D electrophoresis for proteomic studies of skeletal muscle

Tue, 01/28/2014 - 4:40pm

We describe improved methods for large format, two-dimensional gel electrophoresis (2DE) that improve protein solubility and recovery, minimize proteolysis, and reduce the loss of resolution due to contaminants and manipulations of the gels, and thus enhance quantitative analysis of protein spots. Key modifications are: (i) the use of 7 M urea and 2 M thiourea, instead of 9 M urea, in sample preparation and in the tops of the gel tubes; (ii) standardized deionization of all solutions containing urea with a mixed bed ion exchange resin and removal of urea from the electrode solutions; and (iii) use of a new gel tank and cooling device that eliminate the need to run two separating gels in the SDS dimension. These changes make 2DE analysis more reproducible and sensitive, with minimal artifacts. Application of this method to the soluble fraction of muscle tissues reliably resolves ~1800 protein spots in adult human skeletal muscle and over 2800 spots in myotubes.

A unique library of myogenic cells from facioscapulohumeral muscular dystrophy subjects and unaffected relatives: family, disease and cell function

Tue, 01/28/2014 - 4:40pm

To explore possible mechanisms of pathology in facioscapulohumeral muscular dystrophy (FSHD), we generated a novel library of myogenic cells composed of paired cultures derived from FSHD subjects and unaffected first-degree relatives. We prepared cells from biopsies of both biceps and deltoid muscles obtained from each of 10 FSHD and 9 unaffected donors. We used this new collection to determine how family background and disease affected patterns of growth and differentiation, expression of a panel of candidate, and muscle-specific genes, and responses to exogenous stressors. We found that FSHD and unaffected cells had, on average, indistinguishable patterns of differentiation, gene expression, and dose-response curves to staurosporine, paraquat, hydrogen peroxide, and glutathione depletion. Differentiated FSHD and unaffected cultures were both more sensitive to glutathione depletion than proliferating cultures, but showed similar responses to paraquat, staurosporine, and peroxide. For stress responses, the sample size was sufficient to detect a 10% change in effect at the observed variability with a power of >99%. In contrast, for each of these properties, we found significant differences among cells from different cohorts, and these differences were independent of disease status, gender, or muscle biopsied. Thus, though none of the properties we examined could be used to reliably distinguish between FSHD and unaffected cells, family of origin was an important contributor to gene-expression patterns and stressor responses in cultures of both FSHD and unaffected myogenic cells.

Facioscapulohumeral muscular dystrophy family studies of DUX4 expression: evidence for disease modifiers and a quantitative model of pathogenesis

Tue, 01/28/2014 - 4:40pm

Facioscapulohumeral muscular dystrophy (FSHD), the most prevalent myopathy afflicting both children and adults, is predominantly associated with contractions in the 4q35-localized macrosatellite D4Z4 repeat array. Recent studies have proposed that FSHD pathology is caused by the misexpression of the DUX4 (double homeobox 4) gene resulting in production of a pathogenic protein, DUX4-FL, which has been detected in FSHD, but not in unaffected control myogenic cells and muscle tissue. Here, we report the analysis of DUX4 mRNA and protein expression in a much larger collection of myogenic cells and muscle biopsies derived from biceps and deltoid muscles of FSHD affected subjects and their unaffected first-degree relatives. We confirmed that stable DUX4-fl mRNA and protein were expressed in myogenic cells and muscle tissues derived from FSHD affected subjects, including several genetically diagnosed adult FSHD subjects yet to show clinical manifestations of the disease in the assayed muscles. In addition, we report DUX4-fl mRNA and protein expression in muscle biopsies and myogenic cells from genetically unaffected relatives of the FSHD subjects, although at a significantly lower frequency. These results establish that DUX4-fl expression per se is not sufficient for FSHD muscle pathology and indicate that quantitative modifiers of DUX4-fl expression and/or function and family genetic background are determinants of FSHD muscle disease progression.