Genetic Patterns of Selected Muscular Dystrophies in the Muscular Dystrophy Surveillance, Tracking, and Research Network

Background and Objectives

To report the genetic etiologies of Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy (LGMD), congenital muscular dystrophy (CMD), and distal muscular dystrophy (DD) in 6 geographically defined areas of the United States.

Methods

This was a cross-sectional, population-based study in which we studied the genes and variants associated with muscular dystrophy in individuals who were diagnosed with and received care for EDMD, LGMD, CMD, and DD from January 1, 2008, through December 31, 2016, in the 6 areas of the United States covered by the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet). Variants of unknown significance (VUSs) from the original genetic test reports were reanalyzed for changes in interpretation.

Results

Among 243 individuals with definite or probable muscular dystrophy, LGMD was the most common diagnosis (138 cases), followed by CMD (62 cases), DD (22 cases), and EDMD (21 cases). There was a higher proportion of male individuals compared with female individuals, which persisted after excluding X-linked genes (EMD) and autosomal genes reported to have skewed gender ratios (ANO5, CAV3, and LMNA). The most common associated genes were FKRP, CAPN3, ANO5, and DYSF. Reanalysis yielded more definitive variant interpretations for 60 of 144 VUSs, with a mean interval between the original clinical genetic test of 8.11 years for all 144 VUSs and 8.62 years for the 60 reclassified variants. Ten individuals were found to have monoallelic pathogenic variants in genes known to be primarily recessive.

Discussion

This study is distinct for being an examination of 4 types of muscular dystrophies in selected geographic areas of the United States. The striking proportion of resolved VUSs demonstrates the value of periodic re-examinations of these variants. Such re-examinations will resolve some genetic diagnostic ambiguities before initiating repeat testing or more invasive diagnostic procedures such as muscle biopsy. The presence of monoallelic pathogenic variants in recessive genes in our cohort indicates that some individuals with muscular dystrophy continue to face incomplete genetic diagnoses; further refinements in genetic knowledge and diagnostic approaches will optimize diagnostic information for these individuals.

Colorectal Cancer Screening Adherence in Selected Disabilities Over 10 Years

INTRODUCTION

Colorectal cancer (CRC) is the second leading cause of cancer mortality in the U.S.; however, if the population aged 50 years or older received routine screening, approximately 60% of these deaths could be eliminated. This study investigates whether adults, aged 50-75 years, with one of three disabilities (blind/low vision [BLV], intellectual disability [ID], spinal cord injury [SCI]) receive CRC screening at rates equivalent to adults without the three disabilities, by accounting for combinations of recommended CRC screenings during a 10-year period (colonoscopy, sigmoidoscopy, fecal occult blood test).

METHODS

South Carolina Medicaid and Medicare, State Health Plan, and hospital discharge data (2000-2009) were analyzed (2013-2015) to estimate the proportion of adherence to and adjusted odds of CRC screening over time among adults with one of the three disabilities, BLV, ID, or SCI, versus adults without these conditions.

RESULTS

The estimated proportion of adults who adhere to changing recommendations over time was lower for adults with ID (34.32%) or SCI (44.14%) compared with those without these disabilities (48.48%). All three case groups had significantly lower AORs of adherence versus those without (BLV: AOR=0.88, 95% CI=0.80, 0.96; ID: AOR=0.55, 95% CI=0.52, 0.59; SCI: AOR=0.88, 95% CI=0.82, 0.95).

CONCLUSIONS

In this study, adults with BLV, ID, or SCI were less likely to receive and adhere to CRC screening recommendations than those without these disabilities. This method provides a thorough evaluation of adherence to CRC screening by considering levels of adherence during each month of Medicaid or Medicare coverage.

Adherence to US Preventive Services Task Force recommendations for breast and cervical cancer screening for women who have a spinal cord injury

CONTEXT

Women with spinal cord injury (SCI) may face barriers that result in disparities in receipt of recommended mammography and Papanicolaou testing.

SETTING

South Carolina.

PARTICIPANTS

South Carolina women with SCI were identified using International Classification of Diseases codes in 2000-2010 Medicaid and Medicare billing data.

OUTCOME MEASURES

Receipt of mammography and Pap testing was determined using procedure billing codes. Partial proportional odds models were estimated to examine the association between SCI and adherence with screening recommendations from the United States Preventive Services Task Force. Each individual's screening experience was classified as full adherence, partial adherence, or no screening.

RESULTS

The cohort for mammography consisted of 3,173 women with SCI and 6,433 comparison women without SCI. The cohort for Pap testing consisted 5,025 women with SCI and 9,538 comparison women. Women with SCI were less likely to have full adherence with mammography recommendations (aOR = 0.69, 95% CI 0.64, 0.76) and Pap test recommendations (aOR = 0.53, 95% CI 0.49, 0.57). They were more likely to have no mammography screening (aOR = 1.44, 95% CI 1.33, 1.57) and no Pap testing (aOR = 1.89, 95% CI 1.77, 2.03) than women without SCI.

CONCLUSION

Using longitudinal data with multiple outcome levels, women with SCI were less likely to be fully adherent with receipt of recommended breast and cervical cancer screenings and more likely to have no screenings during the eligible years when compared to women without SCI.

Dynamic model for preventing mental retardation in the population: the importance of poverty and deprivation

A dynamic simulation model is used to answer the question, "What is the most effective child health policy initiative for the prevention of mental retardation (MR)?" The impact of medical strategies is contrasted with social interventions to see how they affect the prevalence of MR in the general population. The model is based on data from four U.S. Census and California Vital Statistics reports (1960, 1970, 1980, 1990). An interstate comparison (California and South Carolina) uses 1990 data. The results of the simulations reveal that medical interventions to improve the developmental outcome of low birth weight (LBW) infants did not cause a reduction in the rate of MR in the population after a 24-year trial period. In contrast, reducing the proportion of children living in poverty who are exposed to environmental deprivation significantly decreased (10%) MR at the end of the model's time period. This analysis supports the view that long-term reduction in MR prevalence is attainable by modifying public policies that influence children's development. Effective MR prevention calls for public policy committed to multifaceted health and educational services for both affected parents and their young children.

The delayed immunization of children of migrant farm workers in South Carolina

A study was conducted to evaluate the immunization status of migrant farm worker children in South Carolina. Results of this study indicate that the children receive their immunizations at times which are significantly later than the recommended schedule. The first, second, third, and fourth oral poliomyelitis vaccine (OPV) doses are being given approximately 10, 15, 23, and 32 months late, respectively. Diphtheria, pertussis, tetanus vaccine (DPT) is likewise late with the first, second, third, and fourth doses occurring 9, 14, 20, and 26 months late. The fifth booster dose in both series was timed properly. The mumps, measles, rubella vaccine (MMR) is approximately 28 months late, on average. An evaluation of antibody status of 41 migrant farm worker children (5-10 years old) revealed that, even with aberrant patterns of administration, all children had adequate antibody titers. These data indicate that, although adequate levels of protection are reached with the pattern of immunization that migrant farm worker children have, there are large groups of children that are unprotected early in life when they are most susceptible to these diseases.