Sarah Clauss

Phenotype and course of Hutchinson-Gilford progeria syndrome

BACKGROUND Hutchinson-Gilford progeria syndrome is a rare, sporadic, autosomal dominant syndrome that involves premature aging, generally leading to death at approximately 13 years of age due to myocardial infarction or stroke. The genetic basis of most cases of this syndrome is a change from glycine GGC to glycine GGT in codon 608 of the lamin A (LMNA) gene, which activates a cryptic splice donor site to produce abnormal lamin A; this disrupts the nuclear membrane and alters transcription. METHODS We enrolled 15 children between 1 and 17 years of age, representing nearly half of the worlds known patients with Hutchinson-Gilford progeria syndrome, in a comprehensive clinical protocol between February 2005 and May 2006. RESULTS Clinical investigations confirmed sclerotic skin, joint contractures, bone abnormalities, alopecia, and growth impairment in all 15 patients; cardiovascular and central nervous system sequelae were also documented. Previously unrecognized findings included prolonged prothrombin times, elevated platelet counts and serum phosphorus levels, measured reductions in joint range of motion, low-frequency conductive hearing loss, and functional oral deficits. Growth impairment was not related to inadequate nutrition, insulin unresponsiveness, or growth hormone deficiency. Growth hormone treatment in a few patients increased height growth by 10% and weight growth by 50%. Cardiovascular studies revealed diminishing vascular function with age, including elevated blood pressure, reduced vascular compliance, decreased ankle-brachial indexes, and adventitial thickening. CONCLUSIONS Establishing the detailed phenotype of Hutchinson-Gilford progeria syndrome is important because advances in understanding this syndrome may offer insight into normal aging. Abnormal lamin A (progerin) appears to accumulate with aging in normal cells. (ClinicalTrials.gov number, NCT00094393.)

Efficacy and Safety of Lovastatin Therapy in Adolescent Girls With Heterozygous Familial Hypercholesterolemia

Objective. The present study was designed to evaluate the lipid-altering efficacy, safety, and tolerability of lovastatin treatment in adolescent girls with heterozygous familial hypercholesterolemia. Methods. A total of 54 postmenarchal girls, aged 10 to 17 years, were enrolled in a 24-week, double-blind, randomized, placebo-controlled study. After a 4-week diet/placebo run-in period, patients were randomized to 1 of 2 groups: (1) treatment with diet plus lovastatin 20 mg/day for 4 weeks, followed by diet plus lovastatin 40 mg/day for 20 weeks, or (2) diet plus placebo for 24 weeks. Results. Baseline values of lipids, lipoproteins, and apolipoproteins (apo) were comparable between treatment groups. Lovastatin treatment was efficacious at reducing low-density lipoprotein cholesterol by 23% to 27%, total cholesterol by 17% to 22%, and apo B by 20% to 23% at weeks 4 and 24, respectively. Between-treatment group differences were not statistically significant for triglycerides, very-low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, or apo A-I. Lovastatin was generally safe and well tolerated. There were no clinically significant alterations in vital signs (blood pressure and pulse rate), anthropomorphic measurements (height, weight, and BMI), hormone levels (luteinizing hormone, follicle-stimulating hormone, dehydroepiandrosterone sulfate, estradiol, and cortisol), menstrual cycle length, or tests of liver and muscle function. Conclusions. Lovastatin offers an efficacious and well-tolerated treatment option for improving lipid profiles in adolescent girls with familial hypercholesterolemia.

Ezetimibe treatment of pediatric patients with hypercholesterolemia.

OBJECTIVE To review the efficacy of ezetimibe monotherapy for treatment of hypercholesterolemia in pediatric patients. STUDY DESIGN This is a retrospective review of all pediatric patients who received ezetimibe monotherapy as treatment for hypercholesterolemia and for whom follow-up clinical and lipid results were available. Of 36 identified patients, 26 had lipoprotein profiles suggestive of familial hypercholesterolemia (FH), and 10 had profiles suggestive of familial combined hyperlipidemia (FCHL). RESULTS After a mean 105 days of treatment with ezetimibe (range, 32-175 days), total cholesterol (TC) levels decreased from 7.3 +/- 1.0 mmol/L to 5.7 +/- 1.0 mmol/L (P < .0001), and low-density lipoprotein cholesterol (LDL-C) levels decreased from 5.3 +/- 0.9 mmol/L to 3.9 +/- 0.8 (P < .0001) in patients with FH. In patients with FCHL, TC levels decreased from 6.4 +/- 2.0 mmol/L to 5.6 +/- 0.4 mmol/L (P < or = .002), and LDL-C levels decreased from 4.7 +/- 1.0 mmol/L to 3.8 +/- 0.6 mmol/L (P < or = .005). For all patients, the mean decrease in individual LDL-C values was 1.5 +/- 0.9 mmol/L or 28%. There was no significant change in triglyceride or high-density lipoprotein cholesterol levels with ezetimibe. Patients were maintained on ezetimibe with no adverse effects attributable to the medication for as long as 3.5 years. At a mean of 13.6 months (range, 1-44 months) after the initiation of ezetimibe, LDL-C levels remained decreased at 4.0 +/- 0.6 mmol/L. CONCLUSIONS In this small retrospective series of children and adolescents with hypercholesterolemia, ezetimibe was safe and effective in lowering LDL-C levels.

High rate of coronary artery abnormalities in adolescents and young adults infected with human immunodeficiency virus early in life.

We completed a cross-sectional study of individuals infected with human immunodeficiency virus in early childhood using cardiac magnetic resonance imaging and magnetic resonance angiography. Coronary artery abnormality (CAA) was defined by the presence of luminal narrowing and irregularity of the coronary vessel wall. More than 50% of participants (14/27) had evidence of CAA. Individuals had a high rate of CAA, suggesting possible early atherosclerosis.

Abnormal Cardiac Strain in Children and Young Adults with HIV Acquired in Early Life

BACKGROUND Traditional measures of cardiac function are now often normal in adolescents and young adults treated with antiretroviral therapy for human immunodeficiency virus (HIV) infection. There is, however, evidence of myocardial abnormalities in adults with HIV. Cardiac strain analysis may detect impairment in cardiac function that may be missed by conventional measurements in this population. METHODS This was a retrospective study in which echocardiograms of HIV-infected subjects (n = 28) aged 7 to 29 years who participate in a natural history study of HIV acquired early in life were analyzed and compared with matched controls. Standard echocardiographic measures, along with speckle tracking-derived strain and strain rate, were assessed. RESULTS Among the HIV-infected subjects, the median CD4 count was 667 cells/mm(3), and the mean duration of antiretroviral therapy was 14.6 years. Ejection fractions and fractional shortening were normal. There were no significant differences in measures of systolic or diastolic function between the groups. The HIV-infected group had borderline increased left ventricular mass indices. Global longitudinal and circumferential strain and strain rate, as well as global radial strain rate, were significantly impaired in the HIV-infected group compared with controls. There were no associations identified between left ventricular mass index or strain indices and current CD4 count, CD4 nadir, HIV viral load, or duration of antiretroviral therapy. CONCLUSIONS HIV-infected participants demonstrated impaired strain and strain rate despite having normal systolic function and ejection fractions. Strain and strain rate may prove to be prognostic factors for long-term myocardial dysfunction. Therefore, asymptomatic children and young adults with long-standing HIV infection may benefit from these more sensitive measures.

Quality improvement through collaboration: the National Pediatric Quality improvement Collaborative initiative.

Purpose of review The National Pediatric Quality Improvement Collaborative (NPCQIC) was established to improve outcomes and quality of life in children with hypoplastic left heart syndrome and other single ventricle lesions requiring a Norwood operation. The NPCQIC consists of a network of providers and families collecting longitudinal data, conducting research, and using quality improvement science to decrease variations in care, develop and spread best practices, and decrease mortality. Recent findings Initial descriptive investigation of the collaborative data found interstage care process variations, different surgical strategies, diverse feeding practices, and variable ICU approaches between centers and within sites. Analysis and evaluation of these practice variations have allowed centers to learn from each other and implement change to improve processes. There has been an improvement in performance measures and most importantly, a 39.7% reduction in mortality. Summary The NPCQIC has shown, in a rare disease such as hypoplastic left heart syndrome that a network based on multicenter collaboration, patient (parent) engagement, and quality improvement science can facilitate change in practices and improvement in outcomes.

Cardiovascular effects of metabolic syndrome after transplantation: convergence of obesity and transplant-related factors

Abstract Children are at increased risk of developing metabolic syndrome (MS) after kidney transplantation, which contributes to long-term cardiovascular (CV) morbidities and decline in allograft function. While MS in the general population occurs due to excess caloric intake and physical inactivity, additional chronic kidney disease and transplant-related factors contribute to the development of MS in transplant recipients. Despite its significant health consequences, the interplay of the individual components in CV morbidity in pediatric transplant recipients is not well understood. Additionally, the optimal methods to detect early CV dysfunction are not well defined in this unique population. The quest to establish clear guidelines for diagnosis is further complicated by genetic differences among ethnic groups that necessitate the development of race-specific criteria, particularly with regard to individuals of African descent who carry the apolipoprotein L1 variant. In children, since major CV events are rare and traditional echocardiographic measures of systolic function, such as ejection fraction, are typically well preserved, the presence of CV disease often goes undetected in the early stages. Recently, new noninvasive imaging techniques have become available that offer the opportunity for early detection. Carotid intima-media thickness and impaired myocardial strain detected by speckle tracking echocardiography or cardiac magnetic resonance are emerging as early and sensitive markers of subclinical CV dysfunction. These highly sensitive tools may offer the opportunity to elucidate subtle CV effects of MS in children after transplantation. Current knowledge and future directions are explored in this review.

Comparison of BMI, waist circumference, and waist-to-height ratio for identification of subclinical cardiovascular risk in pediatric kidney transplant recipients

Kidney transplant recipients are at high risk for CV morbidity. However, the measure of obesity that best predicts CV risk has not been established.

Increased carotid intima-media thickness in African American pediatric kidney transplant recipients

Early signs of subclinical CV dysfunction can be detected by ultrasound for CIMT. Although A‐A are at high risk for CV disease, CIMT of A‐A kidney transplant recipients has not been previously investigated. The aim of this prospective, controlled, longitudinal study was to investigate determinants of CIMT in a multiracial pediatric kidney transplant population, with a focus on A‐A. Transplant recipients (n = 42) had BMI, waist‐to‐height ratio, fasting glucose, lipid panel, HbA1c%, and CIMT measured at 1, 18, and 30 months post‐transplant. Twenty‐four healthy children (14 A‐A) served as controls. CIMT of A‐A transplant (0.49, 0.49, and 0.48 mm) was higher than non‐AA transplant (0.43, 0.44, and 0.44 mm) at 1, 18, and 30 months and higher than A‐A controls (0.47 mm). Hyperparathyroidism prior to transplant predicted high CIMT‐for‐race. A‐A race was associated with 10% higher CIMT vs non‐A‐A transplant. Metabolic syndrome was associated with 0.03 ± 0.01 mm increase in CIMT among A‐A transplant recipients only. In conclusion, A‐A kidney transplant recipients have increased CIMT. Metabolic syndrome disproportionately affects CIMT of A‐A children post‐transplant. Identification of subclinical CV damage, detected by CIMT, may provide an opportunity for early detection of CV risk in this vulnerable population.

Community study to uncover the full spectrum of rheumatic heart disease in Uganda

Objective Estimates of the prevalence of rheumatic heart disease (RHD) in many endemic countries are limited to samples of children attending schools, which generate an incomplete picture of disease burden in communities. The present study conducted household-based RHD screening in a representative community in Gulu district, Uganda. Methods Members of households identified through a two-stage cluster-sampling approach between the ages of 5 years and 50 years were invited to undergo limited cardiac testing with a handheld echocardiogram to assess for the presence of RHD. Suspicious cases underwent confirmatory echocardiogram with a fully functional machine. Results Of the 2453 community members screened, 2.45% (95% CI 1.87% to 3.14%) showed echocardiographic evidence of RHD with 1.26% (95% CI 0.860% to 1.79%) having definite RHD. The overall prevalence of RHD among participants <20 years was 2.52% (95% CI 1.78% to 3.45%), with a borderline prevalence of 1.97% (95% CI 1.33% to 2.82%) and a definite prevalence of 0.544% (95% CI 0.235% to 1.07%). Prevalence rates among youth increased with age and peaked in the age group of 16–20 years. The overall adult prevalence (>20 years) of RHD was 2.34% (95% CI 1.49% to 3.49%). The majority of definite cases were mild (81%) and marked by mitral regurgitation and associated morphological valve changes (71%). Conclusion Our data reveal a high prevalence of undiagnosed RHD within an endemic community and fill a critical gap in RHD epidemiology in African adults.