DYNC2H1 hypomorphic or retina-predominant variants cause nonsyndromic retinal degeneration

Purpose: Determining the role of DYNC2H1 variants in nonsyndromic inherited retinal disease (IRD). Methods: Genome and exome sequencing were performed for five unrelated cases of IRD with no identified variant. In vitro assays were developed to validate the variants identified (fibroblast assay, induced pluripotent stem cell [iPSC] derived retinal organoids, and a dynein motility assay). Results: Four novel DYNC2H1 variants (V1, g.103327020_103327021dup; V2, g.103055779A>T; V3, g.103112272C>G; V4, g.103070104A>C) and one previously reported variant (V5, g.103339363T>G) were identified. In proband 1 (V1/V2), V1 was predicted to introduce a premature termination codon (PTC), whereas V2 disrupted the exon 41 splice donor site causing incomplete skipping of exon 41. V1 and V2 impaired dynein-2 motility in vitro and perturbed IFT88 distribution within cilia. V3, homozygous in probands 2–4, is predicted to cause a PTC in a retina-predominant transcript. Analysis of retinal organoids showed that this new transcript expression increased with organoid differentiation. V4, a novel missense variant, was in trans with V5, previously associated with Jeune asphyxiating thoracic dystrophy (JATD). Conclusion: The DYNC2H1 variants discussed herein were either hypomorphic or affecting a retina-predominant transcript and caused nonsyndromic IRD. Dynein variants, specifically DYNC2H1 variants are reported as a cause of non syndromic IRD

Antiphospholipid antibodies and cerebral artery dissection: two frequent causes of brain ischemia in young adults.

As part of a multicenter study on ischemic stroke in the young, we report the occurrence of high antiphospholipid antibody (aPLs) levels and cerebral dissection in 75 patients. These represent the two most frequent non-thromboembolic causes of cerebral ischemia in our population. Increased aPL titres were found in nine cases (12%); cerebral artery dissection in eleven (14%). Our data stress the need to modify the classical diagnostic approach to cerebral ischemia by including hematological assessments and new neuroimaging techniques as screening tests

Life’s What You Make: Niche Construction and Evolutionary Art

Abstract. This paper advances new methods for ecosystemic approaches to evolutionary music and art. We explore the biological concept of the niche and its role in evolutionary dynamics, applying it to creative computational systems. Using the process of niche construction organisms are able to change and adapt their environment, and potentially that of other species. Constructed niches may become heritable environments for offspring, paralleling the way genes are passed from parent to child. In a creative ecosystem, niche construction can be used by agents to increase the diversity and heterogeneity of their output. We illustrate the usefulness of this technique by applying niche construction to line drawing and music composition.