Retinitis pigmentosa (RP) refers to a genetically heterogeneous group of progressive neurodegenerative diseases that result in dysfunction and/or death of rod and cone photoreceptors in the retina. So far, 18 genes have been identified for autosomal-dominant (ad) RP. Here, we describe an adRP locus (RP42) at chromosome 7p15 through linkage analysis in a six-generation Scandinavian family and identify a disease-causing mutation, c.449G-->A (p.S150N), in exon 6 of the KLHL7 gene. Mutation screening of KLHL7 in 502 retinopathy probands has revealed three different missense mutations in six independent families. KLHL7 is widely expressed, including expression in rod photoreceptors, and encodes a 75 kDa protein of the BTB-Kelch subfamily within the BTB superfamily. BTB-Kelch proteins have been implicated in ubiquitination through Cullin E3 ligases. Notably, all three putative disease-causing KLHL7 mutations are within a conserved BACK domain; homology modeling suggests that mutant amino acid side chains can potentially fill the cleft between two helices, thereby affecting the ubiquitination complexes. Mutations in an identical region of another BTB-Kelch protein, gigaxonin, have previously been associated with giant axonal neuropathy. Our studies suggest an additional role of the ubiquitin-proteasome protein-degradation pathway in maintaining neuronal health and in disease.

Retinal degenerative diseases, such as retinitis pigmentosa and Leber congenital amaurosis, are a leading cause of untreatable blindness with substantive impact on the quality of life of affected individuals and their families. Mouse mutants with retinal dystrophies have provided a valuable resource to discover human disease genes and helped uncover pathways critical for photoreceptor function. Here we show that the rd11 mouse mutant and its allelic strain, B6-JR2845, exhibit rapid photoreceptor dysfunction, followed by degeneration of both rods and cones. Using linkage analysis, we mapped the rd11 locus to mouse chromosome 13. We then identified a one-nucleotide insertion (c.420-421insG) in exon 3 of the Lpcat1 gene. Subsequent screening of this gene in the B6-JR2845 strain revealed a seven-nucleotide deletion (c.14-20delGCCGCGG) in exon 1. Both sequence changes are predicted to result in a frame-shift, leading to premature truncation of the lysophosphatidylcholine acyltransferase-1 (LPCAT1) protein. LPCAT1 (also called AYTL2) is a phospholipid biosynthesis/remodeling enzyme that facilitates the conversion of palmitoyl-lysophosphatidylcholine to dipalmitoylphosphatidylcholine (DPPC). The analysis of retinal lipids from rd11 and B6-JR2845 mice showed substantially reduced DPPC levels compared with C57BL/6J control mice, suggesting a causal link to photoreceptor dysfunction. A follow-up screening of LPCAT1 in retinitis pigmentosa and Leber congenital amaurosis patients did not reveal any obvious disease-causing mutations. Previously, LPCAT1 has been suggested to be critical for the production of lung surfactant phospholipids and biosynthesis of platelet-activating factor in noninflammatory remodeling pathway. Our studies add another dimension to an essential role for LPCAT1 in retinal photoreceptor homeostasis.etinitis pigmentosa (RP) constitutes a group of common inherited retinal dystrophies with clinical manifestations, including nyctalopia (night blindness) and loss of peripheral vision. One of the early hallmarks of RP is photoreceptor dysfunction that is followed by the death of rod and then cone photoreceptors. To date, over 40 genes have been associated with inherited forms of RP (Retnet: www.sph.uth.tmc.edu/retnet/); these genes exhibit distinct patterns of expression (e.g., rod-specific or widely expressed) and encode proteins of diverse biological functions (1-3).Animal models of retinal degeneration are a valuable resource in elucidation of genes for human retinal diseases, including RP and Leber congenital amaurosis (LCA) (4, 5). One of the first mouse retinal degeneration lines examined, rd1, was defective in Pde6b, encoding β-subunit of cGMP phosphodiesterase and was determined to have both an insertion and a point mutation (6, 7). The rd7 mouse line resulted from the loss of function of orphan nuclear receptor NR2E3 (8, 9), and rd16 mice carried an in-frame deletion in the broadly expressed Cep290 (10). Cross-species mutation discovery rapidly occurred in each case once the initial disease causing...

We describe a patient with subclinical coccidioidomycosis who experienced rapid disease dissemination shortly after SARS-CoV-2 infection, suggesting host immune response dysregulation to coccidioidomycosis by SARS-CoV-2. We hypothesize that disrupted cell-mediated signaling may result after SARS-CoV-2 infection leading to functional exhaustion and CD8+ T-cell senescence with impairment in host cellular response to Coccidioides infection.

Invasive osteoarticular infections (IOI) due to Scedosporium spp. are rare in the immune competent patient, but have been associated with direct inoculation from antecedent trauma. Here we describe a case of IOI due to Scedosporium dehoogii in a previously healthy man. The clinical presentation and the diagnosis and treatment is discussed. To our knowledge, this is the first reported case of IOI caused by S. dehoogii.