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Supreme Court rules out patents on ‘natural’ genes

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The U.S. Supreme Court ruled on June 13th, 2013 that Myriad “found an important and useful gene, but separating that gene from its surrounding genetic material is not an act of invention.” Raw DNA sequences, even if “isolated” from tissue, are a “product of nature”  and thus are not patentable. The court also ruled that […]



16p11.2 deletion and autism

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The recurrent ~600 kb 16p11.2 deletion, defined by breakpoints 4 and 5 (BP4-BP5), is among the most frequent known genetic aetiologies of autism spectrum disorder (ASD). Its population prevalence is ~ 1/2000, but in ASD it reaches 1/200. Zufferey et al collected clinical data on 285 deletion carriers and performed detailed evaluations on 72 carriers […]



Long Runs of Homozygosity Are Enriched for Deleterious Variation.

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  Szpiech et al are reporting in the latest issue of AJHG their findings about the prevalence of deleterious mutations in ROH. Starting from two contradicting hypotheses, one predicting that ROH should be depleted of deleterious variants compared to the rest of the genome and a second predicting the opposite result, they studied 27 individuals […]



Bowel dysmotility and mitochondrial disease

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Kapur et al. (Am J Surg Path 2011 May;35(5):714-22) described the gastrointestinal neuromuscular pathology of several patients with POLG related mitochondrial disease and gastrointestinal dysmotility. The findings include unusual eosinophilic cytoplasmic granules corresponding to abnormal mitochondrial in parts of the enteric ganglia. Similar pathological findings were previously reported in another mitochondrial disease associated with gastrointestinal dysmotility, MNGIE. In our patient cohort with […]



De novo mutations in histone-modifying genes in congenital heart disease

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Zaidi et al are reporting in Nature the identification of several de novo mutations in genes in the H3K4me pathway in patients with Congenital Heart Disease (CHD). The genes were identified after comparing the incidence of de novo mutations in 362 severe CHD cases and 264 controls by analysing exome sequencing of parent–offspring trios. After selecting for damaging […]



Maternal affect on newborn biochemical markers

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It is well understood that transient elevations in specific acylcarnitine species on the newborn screen can actually originate from the infant’s mother. Often times this is thought to be due to an occult inborn error of metabolism, such as a mother with asymptomatic 3-methylcrotonyl-CoA carboxylase deficiency. However, I have often wondered how other clinical modifiers might contribute to false positive […]



Rhombencephalosynapsis

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Rhombencephalosynapsis is an abnormalty of the cerebellar midline including a missing vermis and fusion of the cerebellar hemispheres with or without other brain abnormalities. Ishak et al. (Brain 2012, Advance access March 26, 2012) offers a nice description of associated genetic syndromes and clinical features associated with this malformation.  Interestingly, this brain abnormality can be […]



Metabolite Proofreading?

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Van Schaftingen et al (JIMD, pub on line Jan 8, 2013) recently wrote a very interesting short review discussing several enzymes whose sole purpose appears to be to process aberrantly produced metabolites. These abnormal metabolites, such as L-2-hydroxyglutarate, are the product of substrate non-specificity of certain enzymes. This group proposes that defects in as of yet unknown “proofreading” enzymes could […]



Analysis of 6,515 exomes reveals the recent origin of most human protein-coding variants

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Fu et al, studied exome sequencing data from 6,515 individual of European American and African American ancestry in order to define the age of Single Nucleotide Variants (SNVs) in the human genome. Using 6 different demographic models and based on a modified Out-of-Africa model, they estimated the age of all of the 1,146,601 identified SNVs. They […]



IVF-gene therapy to prevent mitochondrial disease

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Tachibana et al. demonstrated that the nucleus of an affected woman’s egg could be inserted into healthy donor egg cytoplasm by spindle transfer, allowing the birth of healthy offspring. A child born as a result of this technique will be the genetic child of the patient but carry healthy mitochondrial genes from the donor.   […]