Aileen Kenneson

GJB2 (connexin 26) variants and nonsyndromic sensorineural hearing loss: A HuGE review

Despite the enormous heterogeneity of genetic hearing loss, variants in one locus, Gap Junction Beta 2 or GJB2 (connexin 26), account for up to 50% of cases of nonsyndromic sensorineural hearing loss in some populations. This article reviews genetic epidemiology studies of the alleles of GJB2, prevalence rates, genotype-phenotype relations, contribution to the incidence of hearing loss, and other issues related to the clinical validity of genetic testing for GJB2. This review focuses primarily on three alleles: 167ΔT, 35ΔG, and 235ΔC. These alleles are recessive for nonsyndromic prelingual sensorineural hearing loss, and the evidence suggests complete penetrance but variable expressivity.

Genetics Evaluation Guidelines for the Etiologic Diagnosis of Congenital Hearing Loss

The advent of hearing screening in newborns in many states has led to an increase in the use of genetic testing and related genetic services in the follow-up of infants with hearing loss. A significant proportion of those with congenital hearing loss have genetic etiologies underlying their hearing loss. To ensure that those identified with congenital hearing loss receive the genetic services appropriate to their conditions, the Maternal and Child Health Bureau of the Health Resources and Services Administration funded the American College of Medical Genetics to convene an expert panel to develop guidelines for the genetic evaluation of congential hearing loss. After a brief overview of the current knowledge of hearing loss, newborn screening, and newborn hearing screening, we provide an overview of genetic services and a guideline that describes how best to ensure that patients receive appropriate genetic services. The significant contribution of genetic factors to these conditions combined with the rapid evolution of knowledge about the genetics of these conditions overlaid with the inherently multidisciplinary nature of genetic services provides an example of a condition for which a well-integrated multidisciplinary approach to care is clearly needed.The advent of hearing screening in newborns in many states has led to an increase in the use of genetic testing and related genetic services in the follow-up of infants with hearing loss. A significant proportion of those with congenital hearing loss have genetic etiologies underlying their hearing loss. To ensure that those identified with congenital hearing loss receive the genetic services appropriate to their conditions, the Maternal and Child Health Bureau of the Health Resources and Services Administration funded the American College of Medical Genetics to convene an expert panel to develop guidelines for the genetic evaluation of congential hearing loss. After a brief overview of the current knowledge of hearing loss, newborn screening, and newborn hearing screening, we provide an overview of genetic services and a guideline that describes how best to ensure that patients receive appropriate genetic services. The significant contribution of genetic factors to these conditions combined with the rapid evolution of knowledge about the genetics of these conditions overlaid with the inherently multidisciplinary nature of genetic services provides an example of a condition for which a well-integrated multidisciplinary approach to care is clearly needed.

From Public Health Emergency to Public Health Service: The Implications of Evolving Criteria for Newborn Screening Panels

PEDIATRICS is the official journal of the American Academy of Pediatrics. A monthly publication, it has been published continuously since 1948. PEDIATRICS is owned, published, and trademarked by the American Academy of Pediatrics, 141 Northwest Point Boulevard, Elk Grove Village, Illinois, 60007. Copyright

Health Care Utilization and Expenditures for Children and Young Adults With Muscular Dystrophy in a Privately Insured Population

We provide estimates of medical care utilization and expenditures for children and young adults younger than age 30 with muscular dystrophies in the United States. Accurate estimates are essential for calculations of lifetime costs and for economic evaluations of screening and management strategies for muscular dystrophy. We compare the medical expenditures for persons with muscular dystrophy with others by age groups. The incremental annual expenditures of medical care for privately insured individuals with muscular dystrophy relative to others in 2004 averaged

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

18 930 and ranged from

Methodology of a multistate study of congenital hearing loss: Preliminary data from Utah newborn screening

13 464 at ages 5 to 9 to

Adherence to american academy of pediatrics recommendations for cardiac care among female carriers of duchenne and becker muscular dystrophy.

32 541 at ages 15 to 19. Individuals with muscular dystrophy had average medical expenditures 10 to 20 times greater than individuals without muscular dystrophy. Individuals aged 15 to 19 years had the highest number of inpatient admissions related to respiratory infections and cardiac complications. The findings underscore the need for appropriate treatment options for individuals with muscular dystrophy as they age.

Trends and racial disparities in muscular dystrophy deaths in the United States, 1983–1998: An analysis of multiple cause mortality data

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.

Review and meta-analysis of the epidemiology of congenital cytomegalovirus (CMV) infection.

A multistate Centers for Disease Control and Prevention (CDC) study was designed to investigate the etiology of congenital hearing loss in infants ascertained through state‐mandated hearing screening or early hearing loss detection and intervention (EHDI) programs. At least 50% of permanent childhood‐onset hearing loss is due to genetic causes, and approximately 20% of all infants with congenital hearing loss have mutations in the GJB2 gene. Another 1% of childhood hearing loss is due to mitochondrial DNA (mtDNA) mutations. The specific aims of this study are to 1) classify the etiology of congenital hearing loss in infants by doing prospective genetic evaluations of all newborns with permanent hearing loss from defined geographic areas, 2) determine the frequency of mutations in GJB2 and two common mitochondrial mutations in these populations, and 3) establish a model infrastructure linking genetic services to statewide EHDI programs. As of April 2003, Utah is the only center evaluating patients. Study subjects identified through the Utah Department of Health EHDI program are contacted by letter and offered a comprehensive medical genetics evaluation with DNA testing for GJB2 and mitochondrial mutations A1555G and A7445G. To date, 25 probands and their immediate family members have been evaluated. We have identified 20 cases with nonsyndromic hearing loss (7 multiplex and 13 simplex), 4 with syndromic hearing loss, and 1 with presumed cytomegalovirus (CMV)‐induced hearing loss. Six of 19 (32%) nonsyndromic cases with sensorineural hearing loss have mutations of one or both alleles of the GJB2 gene, and 21% are homozygous or compound heterozygotes for the 35delG mutation. No A1555G or A7445G mtDNA mutations have been found. Data reported to date include only children born in Utah, but EHDI programs in Hawaii, Rhode Island, and designated areas of Georgia have begun enrolling children in what is now a multistate collaborative study. This is the first comprehensive investigation to determine the etiology of hearing loss from populations ascertained through EHDI programs. The results of this study will facilitate the incorporation of genetic services into EHDI programs.

The muscular Dystrophy Surveillance Tracking and Research Network (MD STARnet): surveillance methodology.

Objective. The goal was to assess womens knowledge and heart health behaviors consistent with the American Academy of Pediatrics recommendations for cardiac care among female carriers of Duchenne/Becker muscular dystrophy. Methods. Using an advocacy group mailing list and working with 50 Muscular Dystrophy Association clinics, we surveyed women who had given birth to a son with Duchenne/Becker muscular dystrophy, thought that they were definitely or probably (≥50% likelihood) a Duchenne/Becker muscular dystrophy carrier, or both. Self-report data classified respondents as carriers, noncarriers, or women with unknown status. Results. The respondents included 833 Duchenne/Becker muscular dystrophy carriers, 376 noncarriers, and 192 women with unknown status. Carriers were more likely than noncarriers and women in the unknown-status group to have ever undergone electrocardiography or other heart testing and to have seen a cardiologist in the past year, but they were not more likely to report a recent blood pressure or cholesterol level check. Only 64.4% of the carriers had ever had a heart test; 18.3% had seen a cardiologist in the past year. Only 62.9% of the carriers were aware of their cardiomyopathy risks before participating in the survey; 69.3% had informed their health care provider of their carrier status. Among carriers who had informed their provider, 70.2% had ever had a heart test and 21.4% had seen a cardiologist in the past year. In adjusted logistic regression models, factors that significantly increased the likelihood among carriers of ever having had a heart test and seeing a cardiologist in the previous year included older age (≥50 years), feeling informed about their cardiomyopathy risks before the survey, and having told their provider about their carrier status. Conclusion. More health education efforts are needed for both patients and their providers, to improve adherence to the American Academy of Pediatrics cardiac care guidelines for female Duchenne/Becker muscular dystrophy carriers.