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Braunlin E.,University of Minnesota | Wang R.,CHOC Childrens | Wang R.,University of California at Irvine
Heart | Year: 2016

The growing availability of innovative treatments for rare genetic diseases with a cardiac component-such as the mucopolysaccharidoses (MPSs)-has changed these syndromes from 'back of the textbook' curiosities of childhood to chronic, but rare, adult cardiac conditions that require both centres of expertise and knowledgeable subspecialists. The MPSs are inherited progressive lysosomal storage diseases, occurring in about 1:25 000 births and resulting from absence of functional hydrolases responsible for the degradation of glycosaminoglycans, naturally occurring complex sugars ubiquitous throughout the body. In the heart, accumulation of glycosaminoglycans occurs within the cardiac valves, the epicardial coronary arteries, the myocytes and cardiac interstitium and the walls of the great vessels. As a consequence, cardiac valve regurgitation and stenosis, diffuse coronary artery stenosis, myocardial dysfunction and aortic root dilation often occur. Haematopoietic cell transplantation and enzyme replacement therapy have changed the previously lethal natural history of the MPSs to one of survival well into adulthood. Despite this improved lifespan, the left-sided cardiac valves continue to show progressive functional involvement and cardiac valve replacement is not uncommon, especially in adults. The risk of any intervention is increased in these patients because of the systemic effects of the disease on the respiratory system and cervical cord. Our current understanding of other cardiac issues in adults with the MPSs, especially with the coronary circulation and myocardium, is meagre and more needs to be known to effectively care for this emerging population of adults. Incorporation of the MPSs, as well as other nowtreatable rare diseases, into the educational curriculum of current and future adult subspecialists is an important next step.

Puckett R.L.,CHOC Childrens | Rinaldo P.,Rochester College | Lipson M.H.,Kaiser Permanente | Matern D.,Rochester College | And 4 more authors.
Molecular Genetics and Metabolism | Year: 2010

Newborn screening (NBS) by tandem mass spectrometry (MS/MS) has allowed for early detection and initiation of treatment in many patients with maple syrup urine disease (MSUD) (OMIM 248600), however, a recent report suggests that variants forms may be missed. Information on these patients is limited. We present clinical, biochemical and molecular information on patients with variant forms of MSUD not detected by the California Newborn Screening Program. Between July 2005 and July 2009, 2200,000 newborns were screened in California by MS/MS. Seventeen cases of MSUD were detected and three (two siblings) were missed. Additionally, the NBS cards of two siblings with late onset MSUD, who were born pre-expanded NBS, were retrospectively analyzed. None of the five patients met criteria to be considered presumptive positive for MSUD (leucine > 200 μmol/L and a ratio of leucine/alanine ≥ 1.5). Alloisoleucine (allo-ile) was subsequently analyzed in the NBS cards of all five patients, two of whom were found to have elevated levels. The proband in each family was diagnosed following symptoms triggered by an intercurrent illness or increased protein intake. At diagnosis, leucine levels ranged between 561 and >4528 μmol/L, and allo-ile ranged from 137 to 239 μmol/L. Two affected siblings had normal plasma amino acids when asymptomatic; however, their biochemical profiles were diagnostic of MSUD during intercurrent illnesses. The median age at diagnosis of all patients was one year (range 0.8-6.7). Heterozygous BCKDHB (E1β) mutations (c.832G > A/c.970C > T) were identified in one family and a homozygous DBT (E2) sequence variant (c.1430 T > G) in another. The third family had one identifiable DBT mutation (c.827T > G), however, a second mutation was not detected. This report provides further evidence that NBS by MS/MS is unable to detect all cases of MSUD. Second-tier testing with allo-ile may improve sensitivity; however, some children with variant forms will invariably be missed. © 2009 Elsevier Inc.

PubMed | Shinshu University, University Hospital Freiburg, National Hospital for Neurology and Neurosurgery, National Taiwan University Hospital and 31 more.
Type: | Journal: Orphanet journal of rare diseases | Year: 2015

This paper summarizes the results of a group effort to bring together the worldwide available data on patients who are either homozygotes or compound heterozygotes for mutations in MAT1A. MAT1A encodes the subunit that forms two methionine adenosyltransferase isoenzymes, tetrameric MAT I and dimeric MAT III, that catalyze the conversion of methionine and ATP to S-adenosylmethionine (AdoMet). Subnormal MAT I/III activity leads to hypermethioninemia. Individuals, with hypermethioninemia due to one of the MAT1A mutations that in heterozygotes cause relatively mild and clinically benign hypermethioninemia are currently often being flagged in screening programs measuring methionine elevation to identify newborns with defective cystathionine -synthase activity. Homozygotes or compound heterozygotes for MAT1A mutations are less frequent. Some but not all, such individuals have manifested demyelination or other CNS abnormalities.The goals of the present effort have been to determine the frequency of such abnormalities, to find how best to predict whether they will occur, and to evaluate the outcomes of the variety of treatment regimens that have been used. Data have been gathered for 64 patients, of whom 32 have some evidence of CNS abnormalities (based mainly on MRI findings), and 32 do not have such evidence.The results show that mean plasma methionine concentrations provide the best indication of the group into which a given patient will fall: those with means of 800M or higher usually have evidence of CNS abnormalities, whereas those with lower means usually do not. Data are reported for individual patients for MAT1A genotypes, plasma methionine, total homocysteine (tHcy), and AdoMet concentrations, liver function studies, results of 15 pregnancies, and the outcomes of dietary methionine restriction and/or AdoMet supplementation. Possible pathophysiological mechanisms that might contribute to CNS damage are discussed, and tentative suggestions are put forth as to optimal management.

Wang R.Y.,CHOC Childrens | Bodamer O.A.,University of Miami | Watson M.S.,Medical College of Wisconsin | Wilcox W.R.,Cedars Sinai Medical Center | Wilcox W.R.,University of California at Los Angeles
Genetics in Medicine | Year: 2011

PURPOSE: To develop educational guidelines for the diagnostic confirmation and management of individuals identified by newborn screening, family-based testing after proband identification, or carrier testing in at-risk populations, and subsequent prenatal or postnatal testing of those who are presymptomatic for a lysosomal storage disease. METHODS: Review of English language literature and discussions in a consensus development panel comprised an international group of experts in the clinical and laboratory diagnosis, treatment and management, newborn screening, and genetic aspects of lysosomal storage diseases. RESULTS: Although clinical trial and longitudinal data were used when available, the evidence in the literature is limited and consequently the recommendations must be considered as expert opinion. Guidelines were developed for Fabry, Gaucher, and Niemann-Pick A/B diseases, glycogen storage type II (Pompe disease), globoid cell leukodystrophy (Krabbe disease), metachromatic leukodystrophy, and mucopolysaccharidoses types I, II, and VI. CONCLUSION: These guidelines serve as an educational resource for confirmatory testing and subsequent clinical management of presymptomatic indivduals suspected to have a lysosomal storage disease; they also help to define a research agenda for longitudinal studies such as the American College of Medical Genetics/National Institutes of Health Newborn Screening Translational Research Network. © 2011 Lippincott Williams & Wilkins.

He M.,University of Pennsylvania | Smith L.D.,Childrens Mercy Hospital | Chang R.,CHOC Childrens | Li X.,University of Pennsylvania | Vockley J.,University of Pittsburgh
Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids | Year: 2014

Deficiency of sterol C4 methyl oxidase, encoded by the SC4MOL gene, has recently been described in four patients from three different families. All of the patients presented with microcephaly, congenital cataracts, and growth delay in infancy. The first patient has suffered since the age of six years from severe, diffuse, psoriasiform dermatitis, sparing only her palms. She is now 20 years old. The second patient is a 5 year old girl who has just started to develop dry skin and hair changes. The third and fourth patients are a pair of affected siblings with a severe skin condition since infancy. Quantitative sterol analysis of plasma and skin scales from all four patients showed marked elevation of 4α-methyl- and 4, 4′-dimethylsterols, consistent with a deficiency in the first step of sterol C4 demethylation in cholesterol biosynthesis. Mutations in the SC4MOL have been identified in all of the patients. SC4MOL deficiency is the first autosomal recessive disorder identified in the sterol demethylation complex. Cellular studies with patient-derived fibroblasts have shown a higher mitotic rate than control cells in cholesterol-depleted medium, with increased de novo cholesterol biosynthesis and accumulation of methylsterols. Immunologic analyses of granulocytes and B cells from patients and obligate carriers in the patients' families indicated dysregulation of immune-related receptors. Inhibition of sterol C4 methyl oxidase in human transformed lymphoblasts induced activation of the cell cycle. Additional studies also demonstrated diminished EGFR signaling and disrupted vesicular trafficking in cells from the affected patients. These findings suggest that methylsterols play an important role in epidermal biology by their influence on cell proliferation, intracellular signaling, vesicular trafficking and immune response. SC4MOL is situated within the psoriasis susceptibility locus PSORS9, and may be a genetic risk factor for common skin conditions. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias. © 2013 Elsevier B.V.

PubMed | University of California at Irvine, Illinois College, CHOC Childrens, University of California at Los Angeles and 3 more.
Type: Comparative Study | Journal: Journal of electrocardiology | Year: 2015

The spatial peaks QRS-T angle has been shown to differentiate adult patients with hypertrophic cardiomyopathy (HCM) from controls. We hypothesized that the spatial peaks QRS-T angle would, in isolation, be more accurate than the Italian 12-lead ECG Pre-participation Screening criteria or the Seattle criteria for detecting hypertrophic cardiomyopathy (HCM) in pediatric patients.A retrospective study of pediatric patients with HCM compared to age and gender-matched control patients was undertaken. Significance, odds ratios, sensitivity and specificity of HCM detection of the visually derived spatial peaks QRS-T angle were compared to those of traditional 12-lead ECG criteria using: 1) Italys National Pre-participation Screening Programme criteria; and 2) described criteria from Seattle.ECG results from 130 pediatric HCM patients (14.24.4years) were compared to 470 control patients (normal echocardiograms, mean age 13.44.6years). Meanstandard deviation (SD) values for spatial peaks QRS-T angles were 120.440.7 and 21.313.7 degrees for HCM and controls, respectively (P<0.001). A spatial peaks QRS-T angle cutoff value of >54.9 degrees yielded greater sensitivity and specificity (93.1% and 98.7%, respectively) for detecting HCM over ECG criteria from Italy (68.5% and 48.1%, respectively) or Seattle (64.6% and 78.9%, respectively) with odds ratios at 1039.70 (95% CI 363.03 to 2977.67), 2.01 (95% CI 1.33 to 3.04) and 6.84 (4.49-10.44), respectively.In our cohort, a visually derived spatial peaks QRS-T angle has increased sensitivity and specificity for detection of HCM in pediatric patients compared to currently utilized Italian or Seattle ECG criteria.

Miyake N.,Yokohama City University | Yano S.,University of Southern California | Sakai C.,National Institute of Neuroscience | Hatakeyama H.,National Institute of Neuroscience | And 14 more authors.
Human Mutation | Year: 2013

Mitochondrial complex III (CIII) deficiency is a relatively rare disease with high clinical and genetic heterogeneity. CIII comprises 11 subunits encoded by one mitochondrial and 10 nuclear genes. Abnormalities of the nuclear genes such as BCS1L and TTC19 encoding mitochondrial assembly factors are well known, but an explanation of the majority of CIII deficiency remains elusive. Here, we report three patients from a consanguineous Mexican family presenting with neonatal onset of hypoglycemia, lactic acidosis, ketosis, and hyperammonemia. We found a homozygous missense mutation in UQCRC2 that encodes mitochondrial ubiquinol-cytochrome c reductase core protein II by whole-exome sequencing combined with linkage analysis. On the basis of structural modeling, the mutation (p.Arg183Trp) was predicted to destabilize the hydrophobic core at the subunit interface of the core protein II homodimer. In vitro studies using fibroblasts from the index patient clearly indicated CIII deficiency, as well as impaired assembly of the supercomplex formed from complexes I, III, and IV. This is the first described human disease caused by a core protein abnormality in mitochondrial CIII. © 2012 Wiley Periodicals, Inc.

PubMed | University of California at Irvine and CHOC Childrens
Type: | Journal: Molecular genetics and metabolism reports | Year: 2016

Biotin-thiamine responsive basal ganglia disease (BTBGD) is a rare metabolic condition caused by mutations in the

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