Elucidating the patterns of pleiotropy and its biological relevance in maize.

Pleiotropy-when a single gene controls two or more seemingly unrelated traits-has been shown to impact genes with effects on flowering time, leaf architecture, and inflorescence morphology in maize. However, the genome-wide impact of biological pleiotropy across all maize phenotypes is largely unknown. Here, we investigate the extent to which biological pleiotropy impacts phenotypes within maize using GWAS summary statistics reanalyzed from previously published metabolite, field, and expression phenotypes across the Nested Association Mapping population and Goodman Association Panel. Through phenotypic saturation of 120,597 traits, we obtain over 480 million significant quantitative trait nucleotides. We estimate that only 1.56-32.3% of intervals show some degree of pleiotropy. We then assess the relationship between pleiotropy and various biological features such as gene expression, chromatin accessibility, sequence conservation, and enrichment for gene ontology terms. We find very little relationship between pleiotropy and these variables when compared to permuted pleiotropy. We hypothesize that biological pleiotropy of common alleles is not widespread in maize and is highly impacted by nuisance terms such as population structure and linkage disequilibrium. Natural selection on large standing natural variation in maize populations may target wide and large effect variants, leaving the prevalence of detectable pleiotropy relatively low.

Urgent surgery for COVID-19-positive pediatric patient.

BACKGROUND: We present a case of COVID-19-positive pediatric patient for urgent urological surgery by spinal anesthesia to avoid aerosolizing procedure. CASE PRESENTATION: A 12-year-old, COVID-19-positive boy presented for urgent wound incision and drainage at the circumcision site. Our anesthetic plan consisted of spinal anesthesia with sedation. He was transported from the COVID-19 isolation floor to the negative pressure operating room. He was placed in lateral decubitus position and oxygen was delivered through facemask. Under sedation, spinal anesthesia was achieved at first attempt. The patient maintained spontaneous ventilation without airway intervention. Patient was recovered in the operation room then transported back to the floor. CONCLUSION: Spinal anesthesia is a safe alternative to general endotracheal anesthesia for many pediatric urology procedures. Effective team communication and preparation are keys when caring COVID-19-positive patient in perioperative setting to avoid minimize the risk to healthcare providers.

An 18-Year-Old With Acute-on-Chronic Abdominal Pain.

An 18-year-old woman with a complex past medical history presented with 2 days of vomiting and lower abdominal pain. She had been admitted for the majority of the previous 5 months for recurrent pancreatitis and had undergone a cholecystectomy. Additional symptoms included nausea, anorexia, constipation, and a 40-lb weight loss over 4 months. She appeared uncomfortable, and an examination was remarkable for tachycardia, hypertension, and diffuse abdominal tenderness to light palpation. Her initial laboratory test results revealed mildly elevated liver enzymes (aspartate aminotransferase 68 U/L, alanine aminotransferase 80 U/L) and a normal lipase. She was admitted for pain control and nutritional support. Over the next few days, the lipase increased to 1707 U/L. Despite optimizing her management for acute pancreatitis, the patient's symptoms persisted. Further history gathering and laboratory testing ultimately revealed her diagnosis. Our expert panel reviews her hospital course and elucidates the management of our eventual diagnosis.