DNA Polymerase Epsilon Deficiency Causes IMAGe Syndrome with Variable Immunodeficiency.

During genome replication, polymerase epsilon (Pol ε) acts as the major leading-strand DNA polymerase. Here we report the identification of biallelic mutations in POLE, encoding the Pol ε catalytic subunit POLE1, in 15 individuals from 12 families. Phenotypically, these individuals had clinical features closely resembling IMAGe syndrome (intrauterine growth restriction [IUGR], metaphyseal dysplasia, adrenal hypoplasia congenita, and genitourinary anomalies in males), a disorder previously associated with gain-of-function mutations in CDKN1C. POLE1-deficient individuals also exhibited distinctive facial features and variable immune dysfunction with evidence of lymphocyte deficiency. All subjects shared the same intronic variant (c.1686+32C>G) as part of a common haplotype, in combination with different loss-of-function variants in trans. The intronic variant alters splicing, and together the biallelic mutations lead to cellular deficiency of Pol ε and delayed S-phase progression. In summary, we establish POLE as a second gene in which mutations cause IMAGe syndrome. These findings add to a growing list of disorders due to mutations in DNA replication genes that manifest growth restriction alongside adrenal dysfunction and/or immunodeficiency, consolidating these as replisome phenotypes and highlighting a need for future studies to understand the tissue-specific development roles of the encoded proteins

Long-term effects of medical management on growth and weight in individuals with urea cycle disorders

Low protein diet and sodium or glycerol phenylbutyrate, two pillars of recommended long-term therapy of individuals with urea cycle disorders (UCDs), involve the risk of iatrogenic growth failure. Limited evidence-based studies hamper our knowledge on the long-term effects of the proposed medical management in individuals with UCDs. We studied the impact of medical management on growth and weight development in 307 individuals longitudinally followed by the Urea Cycle Disorders Consortium (UCDC) and the European registry and network for Intoxication type Metabolic Diseases (E-IMD). Intrauterine growth of all investigated UCDs and postnatal linear growth of asymptomatic individuals remained unaffected. Symptomatic individuals were at risk of progressive growth retardation independent from the underlying disease and the degree of natural protein restriction. Growth impairment was determined by disease severity and associated with reduced or borderline plasma branched-chain amino acid (BCAA) concentrations. Liver transplantation appeared to have a beneficial effect on growth. Weight development remained unaffected both in asymptomatic and symptomatic individuals. Progressive growth impairment depends on disease severity and plasma BCAA concentrations, but cannot be predicted by the amount of natural protein intake alone. Future clinical trials are necessary to evaluate whether supplementation with BCAAs might improve growth in UCDs

Genetic Rounds: A Doctor's Encounters in the Field that Revolutionized Medicine

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The Burden of Genetic Disease on Inpatient Care in a Children’s Hospital

The important role of genetics in pediatric illness has been increasingly recognized, but the true impact has not been well delineated. An important study of pediatric inpatient admissions to a children’s hospital in 1978 found a genetic basis for disease in just less than half of admitted patients. We sought to update this study in light of current hospitalization practices and new knowledge about genetics. We systematically reviewed the records of 5,747 consecutive admissions (4,224 individuals), representing 98% of patients admitted in 1996 to Rainbow Babies and Children’s Hospital (Cleveland, OH). Each patient was assigned to one of five groups on the basis of the presence or absence of an underlying chronic medical condition and whether that condition had a genetic basis or susceptibility. An underlying disorder with a significant genetic component was found in 71% of admitted children. The vast majority (96%) of underlying chronic disorders in children in this study were either clearly genetic or had a genetic susceptibility. Total charges for 1996 were >$62 million, of which$50 million (81%) was accounted for by disorders with a genetic determinant. The 34% of admissions with clearly genetic underlying disorders accounted for 50% (>$31 million) of the total hospital charges. The mean length of stay was 40% longer for individuals with an underlying disease with a genetic basis than for those with no underlying disease. Charges and length of stay were similar for children with underlying chronic disorders, regardless of the cause. This study begins to quantify the enormous impact of genetic disease on inpatient pediatrics and the health care system. Additional study and frank public discourse are needed to understand the implications on the future health care workforce and on the utilization of health care resources

The Global Prader–Willi Syndrome Registry: Development, Launch, and Early Demographics

Advances in technologies offer new opportunities to collect and integrate data from a broad range of sources to advance the understanding of rare diseases and support the development of new treatments. Prader–Willi syndrome (PWS) is a rare, complex neurodevelopmental disorder, which has a variable and incompletely understood natural history. PWS is characterized by early failure to thrive, followed by the onset of excessive appetite (hyperphagia). Additional characteristics include multiple endocrine abnormalities, hypotonia, hypogonadism, sleep disturbances, a challenging neurobehavioral phenotype, and cognitive disability. The Foundation for Prader–Willi Research’s Global PWS Registry is one of more than twenty-five registries developed to date through the National Organization of Rare Disorders (NORD) IAMRARE Registry Program. The Registry consists of surveys covering general medical history, system-specific clinical complications, diet, medication and supplement use, as well as behavior, mental health, and social information. Information is primarily parent/caregiver entered. The platform is flexible and allows addition of new surveys, including updatable and longitudinal surveys. Launched in 2015, the PWS Registry has enrolled 1696 participants from 37 countries, with 23,550 surveys completed. This resource can improve the understanding of PWS natural history and support medical product development for PWS

Developing interactions with industry in rare diseases: lessons learned and continuing challenges.

The National Institutes of Health (NIH) established the Rare Diseases Clinical Research Network to address the unique challenges of performing research on rare diseases. The Urea Cycle Disorders Consortium (UCDC) was one of the original ten consortia established. The UCDC represents a unique partnership among clinicians, patients, and the NIH with a primary goal of increasing the development of therapeutics that improve patient outcomes for persons affected with a UCD. Based in part on financial incentives associated with the Orphan Drug Act biopharmaceutical and investment entities have an intense interest in engaging with research consortia like the UCDC, which have compiled potentially valuable longitudinal data characterizing outcomes in a relatively large number of affected individuals. We describe the UCDC experience and the bases for evaluating partnerships with such private entities. We review early industry interactions, the development of policies and procedures, and describe the establishment of an Industry Relations Committee, including guiding principles. Challenges encountered, particularly in the transition when products are approved, and potential solutions are discussed. By building a framework for industry partnerships that guides us in resolving inevitable challenges, we can enthusiastically pursue novel and promising collaborations that can lead to breakthroughs in therapeutic interventions for patients

Thrombosis Risk History and D-dimer Levels in Asymptomatic Individuals with Prader–Willi Syndrome

Individuals with Prader–Willi syndrome (PWS) may be at higher risk of developing blood clots as compared to the typical population, but this risk is poorly understood. It is also unclear if laboratory testing of D-dimer concentration might be useful to screen for thrombosis in PWS. Here, we surveyed the thrombosis history of 883 individuals with PWS and evaluated the D-dimer concentration in a subset of 214 asymptomatic individuals, ages 5–55. A history of at least one blood clot was reported by 3.6% of respondents. Thrombosis increased with age, but no significant difference was found on the basis of sex or family history. Genetic subtype was a significant factor when considering only those with a known subtype, and individuals with a history of edema had significantly more blood clots. In the D-dimer sub-study, ≈15% of participants had high D-dimer concentrations, and 3.7% had D-dimer values more than twice the normal upper limit. One participant with a high D-dimer result was found to have a blood clot. No significant differences in D-dimer results were found on the basis of age, sex, genetic subtype, family history of blood clots, edema history, or BMI. The D-dimer test does not appear to be a sensitive and specific screening tool for blood clots in asymptomatic individuals with PWS