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ABSTRACT: Previous studies have revealed white matter abnormalities in the brains of individuals with phenylketonuria (PKU), but the microstructural nature of these abnormalities and their relationship to phenylalanine (Phe) levels and cognitive outcomes are poorly understood. In the current study, the microstructural integrity of white matter in 29 individuals with early-treated PKU and 12 healthy controls was examined using two complementary diffusion tensor imaging (DTI) approaches: region-of-interest (ROI) based analysis and voxel-wise tract based spatial statistics (TBSS) analysis. Relationships among DTI, executive abilities, and Phe level findings were explored. DTI revealed widespread lowering of mean diffusivity (MD) in the white matter of the PKU group in comparison with the control group. Executive abilities were also poorer for individuals with PKU than controls. Within the PKU group, lower MD was associated with higher Phe level and poorer executive abilities. These findings are the first to demonstrate the interplay among microstructural white matter integrity, executive abilities, and Phe control in individuals with PKU.
Molecular Genetics and Metabolism 04/2013; · 3.19 Impact Factor
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ABSTRACT: Response monitoring (post-error slowing) and inhibitory control (commission errors) were examined in children with phenylketonuria (PKU) and controls (6-18 years) using Go/No-Go tasks with higher (PKU n = 37; control n = 55) versus lower (PKU n = 24; control n = 25) non-target expectancy. On both tasks children with PKU exhibited impaired monitoring and inhibitory control, but the post-error slowing pattern was different. With higher expectancy children with PKU slowed more (less efficient monitoring) and with lower expectancy slowed less (less monitoring) than controls. No effects of age or phenylalanine level were noted. These results indicate that expectancy differentially effects monitoring and inhibitory control in PKU.
Developmental Neuropsychology 04/2013; 38(3):139-52. · 2.56 Impact Factor
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ABSTRACT: ATP-sensitive potassium (KATP) channels were first discovered in the heart 30 years ago. Reconstitution of KATP channel activity by coexpression of members of the pore-forming inward rectifier gene family (Kir6.1, KCNJ8, and Kir6.2 KCNJ11) with sulfonylurea receptors (SUR1, ABCC8, and SUR2, ABCC9) of the ABCC protein subfamily has led to the elucidation of many details of channel gating and pore properties. In addition, the essential roles of Kir6.x and SURx subunits in generating cardiac and vascular KATP(2) and the detrimental consequences of genetic deletions or mutations in mice have been recognized. However, despite this extensive body of knowledge, there has been a paucity of defined roles of KATP subunits in human cardiovascular diseases, although there are reports of association of a single Kir6.1 variant with the J-wave syndrome in the ECG, and 2 isolated studies have reported association of loss of function mutations in SUR2 with atrial fibrillation and heart failure. Two new studies convincingly demonstrate that mutations in the SUR2 gene are associated with Cantu syndrome, a complex multi-organ disorder characterized by hypertrichosis, craniofacial dysmorphology, osteochondrodysplasia, patent ductus arteriosus, cardiomegaly, pericardial effusion, and lymphoedema. This realization of previously unconsidered consequences provides significant insight into the roles of the KATP channel in the cardiovascular system and suggests novel therapeutic possibilities.
Circulation Research 03/2013; 112(7):1059-72. · 9.49 Impact Factor
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ABSTRACT: Objective: Phenylketonuria (PKU) is a hereditary metabolic disorder that often results in neuropsychological impairment, even in individuals treated early and continuously. This study was conducted to examine processing speed, variability in processing speed, and the relationship between processing speed variables and executive abilities in children with early and continuously treated PKU. Method: Participants were 42 children with PKU and 81 typically developing children from 7 to 18 years of age. Children completed 3 computerized reaction time (RT) tasks (simple RT, go/no-go, stimulus-response compatibility) and 7 tasks assessing executive abilities (working memory, inhibitory control, strategic processing). Results: Performance of children with PKU was significantly slower and more variable than that of controls across the 3 tasks administered. When age was considered, it was shown that processing speed improved with age to a comparable degree for both groups. Variability in processing speed, however, decreased more with age for the PKU than control group, reflecting the fact that variability in younger, but not older, children with PKU was greater than that of controls. With regard to executive abilities, processing speed and variability contributed to performance on most, but not all, executive tasks; and after controlling for processing speed and variability, executive impairments were still identified in working memory and inhibitory control (not strategic processing). Conclusions: These findings indicate that information processing is slower and less efficient in children with PKU. In addition, processing speed and variability contribute to some, but not all, of the impairments in executive abilities observed in children with PKU. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Neuropsychology 08/2012; · 3.82 Impact Factor
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ABSTRACT: Chromosome 2p15p16.1 microdeletion is an emerging syndrome recently described in patients with dysmorphic facial features, congenital microcephaly, mild to moderate developmental delay and neurodevelopmental abnormalities. Using clinical ultra-high resolution Affymetrix SNP 6.0 array we identified a de novo interstitial deletion on the short arm of chromosome 2, spanning approximately 2.5 Mb in the cytogenetic band position 2p15p16.1, in a female infant with characteristic features of 2p15p16.1 deletion syndrome including severe developmental delay, congenital microcephaly, intractable epilepsy, and renal anomalies, as well as a congenital choledochal cyst which has not been previously reported in other patients with this cytogenetic defect. We further redefined the previously reported critical region, supporting the presence of a newly recognized microdeletion syndrome involving haploinsufficiency of one or more genes deleted within at least a 1.1 Mb segment of the 2p15p16.1 region.
European journal of medical genetics 04/2012; 55(8-9):485-9. · 1.57 Impact Factor
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ABSTRACT: We treated a patient with multiple congenital joint dislocations and facial dysmorphisms consistent with Larsen syndrome.
Sequencing of the FLNB gene resulted in identification of a novel, de novo 508G>C point mutation resulting in substitution
of proline for a highly conserved alanine (A170P). This mutation has not been described previously but is likely causative
because this alanine is highly conserved and is located in the calponin homology domain where other mutations have been described.
We also report the successful use of a minimally invasive technique in achieving initial correction of bilateral congenital
knee dislocations in this patient. The technique consists of serial manipulations and castings followed by an open quadriceps
tenotomy. Longer followup is needed to ensure maintenance of correction and to avoid the need for more extensive surgery,
which has been the traditional treatment for congenital knee dislocation associated with Larsen syndrome.
Clinical Orthopaedics and Related Research 04/2012; 466(6):1503-1509. · 2.53 Impact Factor
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ABSTRACT: In the current study, we examined a specific aspect of executive abilities, strategic processing, in 32 children with early-treated phenylketonuria (PKU) and 41 typically-developing control children. To do so, clustering and switching were assessed during semantic (animal, food/drink) and phonemic (S, F) fluency tasks. Specifically, number of words generated, number of subcategory clusters, number of words in subcategory clusters, and number of switches between subcategories were analyzed to provide a refined analysis of strategic processing. Compared with controls, children with PKU generated significantly fewer words and made significantly fewer switches between subcategories in the food/drink trial and the phonemic fluency condition. Number of switches was associated with number of words generated in these tasks. In addition, a significant interaction between age and group in number of switches for the food/drink trial reflected a greater increase in number of switches for the control than PKU group as a function of increasing age. These results suggest impairment in frontally-mediated aspects of strategic processing in children with early-treated PKU and indicate that strategic processing should be evaluated carefully as these children age.
Child Neuropsychology 12/2010; 17(2):105-17. · 1.80 Impact Factor
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ABSTRACT: Beckwith-Wiedemann syndrome (BWS) is a clinical diagnosis; however, molecular confirmation via abnormal methylation of DMR2(LIT1) and/or DMR1(H19) has clinical utility due to epigenotype-tumor association. Despite the strong link between H19 hypermethylation and tumor risk, several diagnostic laboratories only test for hypomethylation of LIT1. We assessed the added diagnostic value of combined LIT1 and H19 testing in a large series of referred samples from 1298 patients, including 53 well-characterized patients from the St. Louis Children's Hospital BWS-Registry (validation samples) and 1245 consecutive nationwide referrals (practice samples). Methylation-sensitive enzymatic digestion with Southern hybridization assessed loss of normal imprinting. In the validation group, abnormal LIT1 hypomethylation was detected in 60% (32/52) of patients but LIT1/H19-combined testing was abnormal in 68% (36/53); sensitivity in the practice setting demonstrated 27% (342/1245) abnormal LIT1 and 32% (404/1245) abnormal LIT1/H19-combined. In addition, H19 methylation was abnormal in 7% of LIT1-normal patients. We observed absence of uniparental disomy (UPD) in 27% of combined LIT1/H19-abnormal samples, diagnostic of multilocus methylation abnormalities; in contrast to studies implicating that combined LIT1/H19 abnormalities are diagnostic of UPD. The overall low detection rate, even in validated patient samples and despite characterization of both loci and UPD status, emphasizes the importance of clinical diagnosis in BWS.
The Journal of molecular diagnostics: JMD 09/2010; 12(5):576-88. · 3.48 Impact Factor
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ABSTRACT: Structural, volumetric, and microstructural abnormalities have been reported in the white matter of the brain in individuals with phenylketonuria (PKU). Very little research, however, has been conducted to investigate the development of white matter in children with PKU, and the developmental trajectory of their white matter microstructure is unknown. In the current study, diffusion tensor imaging (DTI) was used to examine the development of the microstructural integrity of white matter across six regions of the corpus callosum in 34 children (7-18 years of age) with early- and continuously-treated PKU. Comparison was made with 61 demographically-matched healthy control children. Two DTI variables were examined: mean diffusivity (MD) and relative anisotropy (RA). RA was comparable to that of controls across all six regions of the corpus callosum. In contrast, MD was restricted for children with PKU in anterior (i.e., genu, rostral body, anterior midbody) but not posterior (posterior midbody, isthmus, splenium) regions of the corpus callosum. In addition, MD restriction became more pronounced with increasing age in children with PKU in the two most anterior regions of the corpus callosum (i.e., genu, rostral body). These findings point to an age-related decrement in the microstructural integrity of the anterior white matter of the corpus callosum in children with PKU.
Molecular Genetics and Metabolism 01/2010; 99 Suppl 1:S41-6. · 3.19 Impact Factor
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ABSTRACT: Noonan syndrome (NS; MIM 163950) is an autosomal dominant dysmorphic syndrome characterized by distinct facial features, cardiac anomalies, short stature, and motor delay. Activating mutations in PTPN11, encoding the protein tyrosine phosphatase SHP2, are associated with about 50% of cases. Mutations in other genes in the RAS/mitogen-activated protein kinase signaling pathway are responsible for many of the remainder of cases. While mutations in this pathway are found in a variety of malignancies, including solid tumors, there are few reports of solid tumors in individuals with NS. We report here a patient with PTPN11 mutation-associated NS and a pilocytic astrocytoma.
Pediatric Blood & Cancer 08/2009; 53(6):1147-9. · 1.89 Impact Factor
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ABSTRACT: Phenylketonuria (PKU) is characterized by a disruption in the metabolism of phenylalanine and is associated with dopamine deficiency (Diamond, Prevor, Callender, & Druin, 1997) and cerebral white matter abnormalities (e.g., Anderson et al., 2007). From a neuropsychological perspective, prefrontal dysfunction is thought to underlie the deficits in executive abilities observed in individuals with PKU (Christ, Steiner, Grange, Abrams, & White, 2006; Diamond et al., 1997; White, Nortz, Mandernach, Huntington, & Steiner, 2001, 2002). The purpose of our study was to examine a specific aspect of executive ability, response monitoring, as measured by posterror slowing. The authors examined posterror reaction time (RT) in 24 children with well-controlled, early treated PKU and 25 typically developing control children using a go/no-go task. Results showed that RTs of both controls and children with PKU slowed significantly following the commission of errors. The magnitude of posterror slowing, however, was significantly less for children with PKU. These findings indicate deficient response monitoring in children with PKU.
Neuropsychology 01/2009; 23(1):130-4. · 3.82 Impact Factor
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ABSTRACT: Curry-Jones syndrome (OMIM #601707) is a rare multiple malformation disorder of unknown etiology, associated with brain and skull abnormalities, polysyndactyly, and defects of the eyes, skin and gastrointestinal tract. We report on two new cases of Curry-Jones syndrome with previously unreported features, including benign and malignant neoplasms. The first patient had typical features of Curry-Jones syndrome as well as multiple intra-abdominal smooth muscle hamartomas and trichoblastoma of the skin. The second patient was born with occipital meningoceles and developed a desmoplastic medulloblastoma. Routine lymphocyte karyotype, GLI3 gene analysis and Patched (PTCH) gene analysis on both patients and chromosome microarray analysis on the first patient were normal. We review the previously reported cases of Curry-Jones syndrome and compare our patients' findings. In view of the association of trichoblastoma with basal cell carcinoma and desmoplastic medulloblastoma with nevoid basal cell carcinoma syndrome (NBCCS) and PTCH mutations, we hypothesize that Curry-Jones syndrome is caused by malfunction of an element in the sonic hedgehog pathway.
American Journal of Medical Genetics Part A 10/2008; 146A(20):2589-97. · 2.39 Impact Factor
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ABSTRACT: We treated a patient with multiple congenital joint dislocations and facial dysmorphisms consistent with Larsen syndrome. Sequencing of the FLNB gene resulted in identification of a novel, de novo 508G>C point mutation resulting in substitution of proline for a highly conserved alanine (A170P). This mutation has not been described previously but is likely causative because this alanine is highly conserved and is located in the calponin homology domain where other mutations have been described. We also report the successful use of a minimally invasive technique in achieving initial correction of bilateral congenital knee dislocations in this patient. The technique consists of serial manipulations and castings followed by an open quadriceps tenotomy. Longer followup is needed to ensure maintenance of correction and to avoid the need for more extensive surgery, which has been the traditional treatment for congenital knee dislocation associated with Larsen syndrome.
Clinical Orthopaedics and Related Research 07/2008; 466(6):1503-9. · 2.53 Impact Factor
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ABSTRACT: Hutchinson-Gilford progeria syndrome (HGPS) is a rare precocious aging syndrome caused by mutations in LMNA that lead to synthesis of a mutant form of prelamin A, generally called progerin, that cannot be processed to mature lamin A. Most HGPS patients have a recurrent heterozygous de novo mutation in exon 11 of LMNA, c.1824C>T/p.G608G; this synonymous mutation activates a nearby cryptic splice donor site, resulting in synthesis of the mutant prelamin A, progerin, which lacks 50 amino acids within the carboxyl-terminal domain. Abnormal splicing is incomplete, so the mutant allele produces some normally-spliced transcripts. Nevertheless, the synthesis of progerin is sufficient to cause misshapen nuclei in cultured cells and severe disease phenotypes in affected patients. Here we present two patients with extraordinarily severe forms of progeria caused by unusual mutations in LMNA. One had a splice site mutation (c.1968+1G>A; or IVS11+1G>A), and the other had a novel synonymous coding region mutation (c.1821G>A/p.V607V). Both mutations caused very frequent use of the same exon 11 splice donor site that is activated in typical HGPS patients. As a consequence, the ratios of progerin mRNA and protein to wild-type were higher than in typical HGPS patients. Fibroblasts from both patients exhibited nuclear shape abnormalities typical of HGPS, and cells treated with a protein farnesyltransferase inhibitor exhibited fewer misshapen nuclei. Thus, farnesyltransferase inhibitors may prove to be useful even when progerin expression levels are higher than those in typical HGPS patients.
Human Mutation 10/2007; 28(9):882-9. · 5.69 Impact Factor
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ABSTRACT: Cantu syndrome, or hypertrichosis-osteodysplasia-cardiomegaly syndrome, is a rare disorder of unknown etiology, associated with hypertrichosis, characteristic facial features, skeletal abnormalities, cardiomegaly, and occasional pericardial effusions. Although autosomal recessive inheritance was originally proposed, a man with three affected children has been reported, making autosomal dominant inheritance likely. We report on a woman and her two daughters with Cantu syndrome, further confirming dominant inheritance. All three of our patients have cardiac involvement, and symptomatic pericardial effusions requiring surgical intervention occurred in the mother and one of her daughters. Chromosome microarray analysis was normal in one of the girls. The etiology of the cardiomegaly and pericardial effusions in Cantu syndrome is unknown. We review all previously reported cases of Cantu syndrome and the associated cardiac manifestations.
American Journal of Medical Genetics Part A 09/2006; 140(15):1673-80. · 2.39 Impact Factor
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ABSTRACT: Past studies have reported impairments in children with early-treated phenylketonuria (PKU) in executive abilities such as strategic processing and working memory. Findings have been inconsistent in terms of the integrity of inhibitory control, another executive ability. This study administered 4 inhibitory tasks (flanker, Stroop, go/no-go, antisaccade) to 26 children with PKU and 25 typically developing control children. Children with PKU performed more poorly than typically developing children on the 2 inhibitory tasks with the strongest experimental manipulations (go/no-go and antisaccade) between control and inhibitory conditions. Findings suggest that the inhibitory deficit associated with PKU is subtle and that inconsistent findings in past studies may be largely due to the insensitivity of experimental manipulations in some tasks.
Developmental Neuropsychology 02/2006; 30(3):845-64. · 2.56 Impact Factor
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ABSTRACT: Menkes disease is an X-linked recessive disorder of copper transport characterized by neurological deterioration, connective tissue, and vascular defects, abnormal hair, and death in early childhood. We report on a patient with Menkes disease in whom severe diffuse emphysema caused respiratory failure and death at 14 months of age. He had severe growth and developmental delays and other typical clinical manifestations of Menkes disease. He developed respiratory problems requiring continuous supplemental oxygen and a progressively enlarging soft tissue mass appeared on the neck. Imaging studies revealed cystic spaces in multiple lobes of the lung consistent with bullous emphysema. The neck mass was determined to be an internal jugular venous aneurysm. At autopsy, extensive emphysematous change was evident. Post-mortem barium injections of the pulmonary arterial system revealed marked dilatation and tortuosity of the preacinar pulmonary arteries and reduced numbers of intra-acinar arteries. Severe emphysema, presumably caused by abnormal elastin due to deficiency of the copper-dependent enzyme lysyl oxidase, may represent an underestimated clinical complication of Menkes disease and should be considered in the differential diagnosis of chronic respiratory disease in these patients.
American Journal of Medical Genetics Part A 01/2006; 139A(2):151-5. · 2.39 Impact Factor
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ABSTRACT: We report on a patient with a rec(20)dup(20q) chromosome abnormality derived from a paternal chromosome 20 inversion [inv(20)(p13q13.1)]. The rearrangement results in a duplication of 20q13.1 to 20qter and a deletion of 20p13 to 20pter. The patient is a girl with craniofacial features and multiple congenital malformations that overlap with the abnormalities previously described in trisomy 20q syndrome. To our knowledge this is the first report of a patient with rec(20)dup 20q.
American Journal of Medical Genetics Part A 10/2005; 137A(3):308-12. · 2.39 Impact Factor
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ABSTRACT: Sialidosis is a lysosomal storage disease characterized by accumulation of sialylated oligosaccharides in tissues, blood and urine and is caused by mutations in the gene for lysosomal alpha-neuraminidase (NEU1). There is wide variability in the age of onset and severity of symptoms in sialidosis. We report here a case of sialidosis due to novel mutations in NEU1 presenting as severe nonimmune hydrops fetalis.
Journal of Perinatology 08/2005; 25(7):491-4. · 1.80 Impact Factor
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ABSTRACT: We performed LIT1 and H19 methylation studies on 27 children with isolated hemihyperplasia (IH). Eight children (29.6%) had a defect in methylation of one or both of these alleles, supporting our hypothesis that these epigenetic changes can result in a phenotype distinct from typical Beckwith-Wiedemann syndrome.
American Journal of Medical Genetics Part A 05/2005; 134A(2):129-31. · 2.39 Impact Factor
