Time to diagnosis in rapid exome/genome sequencing in the clinical inpatient setting.

Exome and genome sequencing are clinically available, with many laboratories offering expedited testing (e.g., "rapid" and "ultra-rapid"). With the increase in uptake of expedited testing, there is a need for the development of inpatient protocols for best practices based on real-life data. A retrospective 2-year review (October 2019-November 2021) of the utilization of rapid exome and genome sequencing for inpatient cases at a tertiary care center using a utilization management tracking database with subsequent chart review was performed. Thirty-three expedited "rapid/priority" exome/genome tests were performed clinically. The average total turnaround time (TAT) was 17.88 days (5-43 days) with an average TAT of 13.97 days (3-41 days) for the performing laboratory. There were 5 positive diagnostic results (15.2%), 3 likely positive diagnostic results (9%), 2 noncontributory results (6%), and 26 nondiagnostic results (69.7%). Real-life data suggest that there is an approximately 3.91-day lag in getting samples to the performing laboratory. Although laboratories may advertise their expected TAT, a number of factors can potentially impact the actual time from test order placement to communication of the results for clinical use. Understanding the points of delay will enable the development of internal protocols and policies to improve time to diagnosis.

A homozygous Gly470Ala variant in PEX6 causes severe Zellweger spectrum disorder.

Zellweger spectrum disorder (ZSD) is a group of autosomal recessive disorders caused by biallelic pathogenic variants in any one of the 13 PEX genes essential for peroxisomal biogenesis. We report a cohort of nine infants who presented at birth with severe neonatal features suggestive of ZSD and found to be homozygous for a variant in PEX6 (NM_000287.4:c.1409G > C[p.Gly470Ala]). All were of Mixtec ancestry and identified by the California Newborn Screening (NBS) Program to have elevated C26:0-lysophosphatidylcholine but no reportable variants in ABCD1. The clinical and biochemical features of this cohort are described within. Gly470Ala may represent a founder variant in the Mixtec population of Central California. ZSD should be considered in patients who present at birth with severe hypotonia and enlarged fontanelles, especially in the setting of an abnormal NBS, Mixtec ancestry, or family history of infant death. There is a need to further characterize the natural history of ZSD, the Gly470Ala variant, and expand upon possible genotype-phenotype correlations.

Increasing evidence that bats actively forage at wind turbines.

Although the ultimate causes of high bat fatalities at wind farms are not well understood, several lines of evidence suggest that bats are attracted to wind turbines. One hypothesis is that bats would be attracted to turbines as a foraging resource if the insects that bats prey upon are commonly present on and around the turbine towers. To investigate the role that foraging activity may play in bat fatalities, we conducted a series of surveys at a wind farm in the southern Great Plains of the US from 2011-2016. From acoustic monitoring we recorded foraging activity, including feeding buzzes indicative of prey capture, in the immediate vicinity of turbine towers from all six bat species known to be present at this site. From insect surveys we found Lepidoptera, Coleoptera, and Orthoptera in consistently high proportions over several years suggesting that food resources for bats were consistently available at wind turbines. We used DNA barcoding techniques to assess bat diet composition of (1) stomach contents from 47 eastern red bat (Lasiurus borealis) and 24 hoary bat (Lasiurus cinereus) carcasses collected in fatality searches, and (2) fecal pellets from 23 eastern red bats that were found on turbine towers, transformers, and tower doors. We found that the majority of the eastern red bat and hoary bat stomachs, the two bat species most commonly found in fatality searches at this site, were full or partially full, indicating that the bats were likely killed while foraging. Although Lepidoptera and Orthoptera dominated the diets of these two bat species, both consumed a range of prey items with individual bats having from one to six insect species in their stomachs at the time of death. The prey items identified from eastern red bat fecal pellets showed similar results. A comparison of the turbine insect community to the diet analysis results revealed that the most abundant insects at wind turbines, including terrestrial insects such as crickets and several important crop pests, were also commonly eaten by eastern red and hoary bats. Collectively, these findings suggest that bats are actively foraging around wind turbines and that measures to minimize bat fatalities should be broadly implemented at wind facilities.