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Did the neuron evolve twice?

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Due to its complexity, the neuron as a specialized cell is assumed to have evolved only once in the history of life. However, the information from the newly sequenced genome of a comb jelly appears to suggest otherwise. Based on their DNA data these invertebrates were classified on a different, older branch of the tree of […]



Gene therapy for ethylmalonic encephalopathy

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Ethylmalonic encephalopathy is caused by a deficiency of a mitochondrial sulfur dioxygenase (leading to the accumulation of sulfides in mitochondria, which impair mitochondrial energy metabolism). Ethylmalonic encephalopathy is characterized by neurodevelopmental delay and regression, prominent pyramidal and extrapyramidal signs, recurrent petechiae, orthostatic acrocyanosis, and chronic diarrhea. Now, using an adeno-associated virus to deliver the ETHE1 […]



Chromosome 16p11 duplications

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I recently saw a child with autism, obsessive compulsive disorder, and anxiety, but who was non-dysmorphic and otherwise healthy. A karyotype from several years ago noted a euchromatic variant at chromosome 16p11, but a reinterpretation of this region has allowed us to diagnose this child with the chromosome 16p11 duplication syndrome. The 16p11.2-p12.2 duplication syndrome is associated […]



mtDNA mutation load in polar bodies vs. oocytes

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It is currently not possible to predict the outcome of children born to mothers who are carrying by delerious mtDNA mutations such as those causing MELAS and MERRF, due to the variable amounts of abnormal mtDNA that are passed to each offspring. cheap viagra super active This can make reproductive decisions very difficult for families. […]



2-Methylbutyryl-coenzyme A dehydrogenase deficiency

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Since the addition of the acylcarnitine profile to the newborn screen, debates about which conditions to include an exclude are becoming a very important issue. There are several “conditions” that are detected that are thought to be probably clin buy cialis online without a prescription ically insignificant. One of these “conditions” is 2-Methylbutyryl-coenzyme A dehydrogenase […]



Propionic Acidemia and Renal Failure

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One of our adult propionic acidemia patients was recently diagnosed with advanced stage chronic kidney disease (CKD). While CKD is a known complication of methylmalonic acidemia, reports of CKD in propionic acidemia are limited. The most recent report is by Lam et al. in Mol Genet Metab. 2011 Aug;103(4):338-40,  where they describe a 45 year old woman with […]



NMNAT1 mutations cause Leber congenital amaurosis

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Falk et al, Chiang et al, Perrault et al, Koenekopp et al are reporting independently in Nat Genetics the identification of NMNAT1 as cause for an autosomal recessive form Leber Congenital Amaurosis(LCA) and all individuals with NMNAT1 mutations also had macular colobomas, due to severe degeneration of the central retina. NMNAT1 is the gene linked to […]



Creatine abnormalities and Arginine Availability

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Arginine availability appears to play a very interesting role in how it affects the creatine synthetic pathway. For example, in arginase deficiency, high levels of arginine have been implicated in causing elevated guanidino compounds, which is thought to play a role in neurologic abnormalities. Conversely, Boenzi et al. (JIMD Volume 35, Number 4 (2012), 647-653) recently reported […]



Exome sequencing of extreme phenotypes identifies DCTN4 as a modifier of chronic Pseudomonas aeruginosa infection in cystic fibrosis.

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Emond et al are reporting in Nat Genetics the identification of DCTN4 as a modifier for P.aeruginosa infection in patients with cystic fibrosis. It is a well-established fact that the majority of patients with cystic fibrosis develop acute and chronic P.aerugonisa infections which are associated with a worse clinical outcome. The authors selected and exome […]