Insect cryptochromes: gene duplication and loss define diverse ways to construct insect circadian clocks

Cryptochrome (CRY) proteins are components of the central circadian clockwork of metazoans. Phylogenetic analyses show at least 2 rounds of gene duplication at the base of the metazoan radiation, as well as several losses, gave rise to 2 cryptochrome (cry) gene families in insects, a Drosophila-like cry1 gene family and a vertebrate-like cry2 family. Previous studies have shown that insect CRY1 is photosensitive, whereas photo-insensitive CRY2 functions to potently inhibit clock-relevant CLOCK:CYCLE-mediated transcription. Here, we extended the transcriptional repressive function of insect CRY2 to 2 orders--Hymenoptera (the honeybee Apis mellifera and the bumblebee Bombus impatiens) and Coleoptera (the red flour beetle Tribolium castaneum). Importantly, the bee and beetle CRY2 proteins are not light sensitive in culture, in either degradation of protein levels or inhibitory transcriptional response, suggesting novel light input pathways into their circadian clocks as Apis and Tribolium do not have CRY1. By mapping the functional data onto a cryptochrome/6-4 photolyase gene tree, we find that the transcriptional repressive function of insect CRY2 descended from a light-sensitive photolyase-like ancestral gene, probably lacking the ability to repress CLOCK:CYCLE-mediated transcription. These data provide an evolutionary context for proposing novel circadian clock mechanisms in insects

Actionable exomic incidental findings in 6503 participants: challenges of variant classification

Recommendations for laboratories to report incidental findings from genomic tests have stimulated interest in such results. In order to investigate the criteria and processes for assigning the pathogenicity of specific variants and to estimate the frequency of such incidental findings in patients of European and African ancestry, we classified potentially actionable pathogenic single-nucleotide variants (SNVs) in all 4300 European- and 2203 African-ancestry participants sequenced by the NHLBI Exome Sequencing Project (ESP). We considered 112 gene-disease pairs selected by an expert panel as associated with medically actionable genetic disorders that may be undiagnosed in adults. The resulting classifications were compared to classifications from other clinical and research genetic testing laboratories, as well as with in silico pathogenicity scores. Among European-ancestry participants, 30 of 4300 (0.7%) had a pathogenic SNV and six (0.1%) had a disruptive variant that was expected to be pathogenic, whereas 52 (1.2%) had likely pathogenic SNVs. For African-ancestry participants, six of 2203 (0.3%) had a pathogenic SNV and six (0.3%) had an expected pathogenic disruptive variant, whereas 13 (0.6%) had likely pathogenic SNVs. Genomic Evolutionary Rate Profiling mammalian conservation score and the Combined Annotation Dependent Depletion summary score of conservation, substitution, regulation, and other evidence were compared across pathogenicity assignments and appear to have utility in variant classification. This work provides a refined estimate of the burden of adult onset, medically actionable incidental findings expected from exome sequencing, highlights challenges in variant classification, and demonstrates the need for a better curated variant interpretation knowledge base

Weighing the evidence for newborn screening for early-infantile Krabbe disease

PURPOSE: To summarize the evidence regarding screening, diagnosis, and treatment of early-infantile Krabbe disease in consideration of its addition to the core panel for newborn screening as has been done in New York state. METHODS: Systematic review of articles indexed in MEDLINE and Embase published between January 1988 and July 2009. Thirteen articles describing studies related to screening, diagnosis, or treatment were included in this review. RESULTS: Case series studies suggest that allogeneic hematopoietic stem-cell transplantation soon after the development of signs or symptoms of early-infantile Krabbe disease decreases early-childhood mortality and may improve neurodevelopment. However, limited data suggest there may be loss of motor function among some children who undergo transplantation. No long-term follow-up data are available from these case series. Of the approximately 550,000 newborns reported to have been screened in New York, 25 tested positive. None of these were clinically recognized to have Krabbe disease prior these results. Four were considered to be high risk for early-onset Krabbe disease. Two were subsequently diagnosed and underwent stem-cell transplantation, of whom one died from complications. No data are available regarding the impact on families of a positive newborn screen. CONCLUSIONS: Although early treatment with hematopoietic stem-cell transplant seems to alter early-childhood mortality and some of the morbidity associated with early-infantile Krabbe disease, significant gaps in knowledge exist regarding the accuracy of screening, the strategy for establishing diagnosis, the affect of a positive screen on families, the benefits and harms of treatment, and long-term prognosis

An evidence development process for newborn screening

This article describes the background, development, and initial implementation of new procedures for the systematic review of key issues in newborn screening. Building on the work of other systematic review efforts, the Evidence Review Group described here has aimed to develop consistent and transparent strategies for evidence review. This process has helped to strengthen a complex analysis and decision system by providing balanced evidence, taking into account available high-quality data, expert opinion, and other levels of evidence, in a transparent manner. The methods developed and the identification of areas of missing data may also help investigators begin to standardize the clinical and laboratory data they collect pertaining to the newborn screening and diagnosis of rare disorders and their outcomes and focus future research efforts in the most needed areas

Actionable exomic incidental findings in 6503 participants: challenges of variant classification

Recommendations for laboratories to report incidental findings from genomic tests have stimulated interest in such results. In order to investigate the criteria and processes for assigning the pathogenicity of specific variants and to estimate the frequency of such incidental findings in patients of European and African ancestry, we classified potentially actionable pathogenic single-nucleotide variants (SNVs) in all 4300 European- and 2203 African-ancestry participants sequenced by the NHLBI Exome Sequencing Project (ESP). We considered 112 gene-disease pairs selected by an expert panel as associated with medically actionable genetic disorders that may be undiagnosed in adults. The resulting classifications were compared to classifications from other clinical and research genetic testing laboratories, as well as with in silico pathogenicity scores. Among European-ancestry participants, 30 of 4300 (0.7%) had a pathogenic SNV and six (0.1%) had a disruptive variant that was expected to be pathogenic, whereas 52 (1.2%) had likely pathogenic SNVs. For African-ancestry participants, six of 2203 (0.3%) had a pathogenic SNV and six (0.3%) had an expected pathogenic disruptive variant, whereas 13 (0.6%) had likely pathogenic SNVs. Genomic Evolutionary Rate Profiling mammalian conservation score and the Combined Annotation Dependent Depletion summary score of conservation, substitution, regulation, and other evidence were compared across pathogenicity assignments and appear to have utility in variant classification. This work provides a refined estimate of the burden of adult onset, medically actionable incidental findings expected from exome sequencing, highlights challenges in variant classification, and demonstrates the need for a better curated variant interpretation knowledge base

Actionable exomic incidental findings in 6503 participants: challenges of variant classification

Recommendations for laboratories to report incidental findings from genomic tests have stimulated interest in such results. In order to investigate the criteria and processes for assigning the pathogenicity of specific variants and to estimate the frequency of such incidental findings in patients of European and African ancestry, we classified potentially actionable pathogenic single-nucleotide variants (SNVs) in all 4300 European- and 2203 African-ancestry participants sequenced by the NHLBI Exome Sequencing Project (ESP). We considered 112 gene-disease pairs selected by an expert panel as associated with medically actionable genetic disorders that may be undiagnosed in adults. The resulting classifications were compared to classifications from other clinical and research genetic testing laboratories, as well as with in silico pathogenicity scores. Among European-ancestry participants, 30 of 4300 (0.7%) had a pathogenic SNV and six (0.1%) had a disruptive variant that was expected to be pathogenic, whereas 52 (1.2%) had likely pathogenic SNVs. For African-ancestry participants, six of 2203 (0.3%) had a pathogenic SNV and six (0.3%) had an expected pathogenic disruptive variant, whereas 13 (0.6%) had likely pathogenic SNVs. Genomic Evolutionary Rate Profiling mammalian conservation score and the Combined Annotation Dependent Depletion summary score of conservation, substitution, regulation, and other evidence were compared across pathogenicity assignments and appear to have utility in variant classification. This work provides a refined estimate of the burden of adult onset, medically actionable incidental findings expected from exome sequencing, highlights challenges in variant classification, and demonstrates the need for a better curated variant interpretation knowledge base