Longitudinal phenotypic study of late-onset retinal degeneration due to a founder variant c.562C>A p.(Pro188Thr) in the C1QTNF5 gene.

Background: Late-onset retinal degeneration (L-ORD) is a rare autosomal dominant retinal dystrophy related to C1QTNF5 gene variants.Materials and methods: Twenty-six patients (21-81 years) with L-ORD due to c.562C>A p.(Pro188Thr) with a mean follow-up time of 8 years (range 1-37 years) underwent an extensive ophthalmic work-up.Results: Best-corrected visual acuity (BCVA) and visual fields were maintained up to 50 to 55 years (n = 8), with a gradual decline, but conservation of functional central vision between 55 to 65 years (n = 15), followed by a steep decrease in overall visual function beyond 65 years (n = 9). Classic anterior segment findings in L-ORD of abnormally long, anteriorly inserted lens zonules were absent in most patients (n = 24/26). In contrast, findings of iris transillumination and sphincter pupillae atrophy with poor dilation were novel. Patients presented with three completely different initial fundus phenotypes: adjoining pavingstone-like atrophic patches (type 1) (n = 6/20); tiny yellow-white subretinal dots (type 2) (n = 8/20); or larger yellow, thick, round sub-RPE drusenoid deposits (type 3) (n = 4/20). Two patients had a mixed phenotype. Although different in presentation phenotype, patients eventually all progressed to a common panretinal atrophy with diffuse intraretinal pigment migration beyond the age of 65. Progression pace, and thus visual prognosis, differed depending on presentation phenotype. Specifically, type 2 appears to have a more benign course.Conclusions: Phenotypic analysis showed three distinct presenting phenotypes with a considerable intrafamilial variability both in age of onset of clinical signs and in disease progression, with a fair visual potential (>20/40) until the seventh decade.Abbreviations: L-ORD: Late-onset retinal degeneration; C1QTNF5: complement 1Q tumor necrosis factor 5; OCT: Ocular coherence tomography; BCVA: Best-corrected visual acuity; RPE: Retinal pigment epithelium; ffERG: Full-field electroretinography; IRD: Inherited retinal dystrophy; CNV: Choroidal neovascularization; LAZ: Long anteriorly inserted zonules; AMPK: AMP-activated protein kinase; IOP: Intraocular pressure; cSLO: confocal scanning laser ophthalmoscopy; BAF: Blue light autofluorescence; NIR-AF: Near-infrared autofluorescence; NIR-R: Near-infrared reflectance; RF: Red-free; SD-OCT: Spectral domain ocular coherence tomography; HRR: Hardy-Rand-Rittler pseudo-isochromatic plates; AS: anterior segment; UBM: ultrasound biomicroscopy; PCR: Polymerase chain reaction; SNP: Single nucleotide polymorphism; VEGF: Vascular endothelial growth factor; IZ: Interdigitation zone; EZ: Ellipsoid zone; ELM: External limiting membrane; LP: Light perception; AMD: Age-related macular degeneration; SFD: Sorsby fundus dystrophy.

The impact of elective caesarean section on colostrum characteristics in double-muscled Belgian Blue cows.

Identification of factors associated with the quality and quantity of colostrum production has always been a major challenge in cattle industry. In purebred double-muscled Belgian Blue (BB) cows, parturition is mainly performed by elective caesarean section (CS; >90%). However, the CS itself may influence colostrum production characteristics. The present study aimed to evaluate the impact of maternal and newborn calf factors and the duration of the procedure of CS on the quality and quantity of colostrum production in BB cows. The dataset includes 551 records of cow-calf pairs that were presented for an elective CS at the Ghent University veterinary clinic between 2017 and 2019. The quality (measured via a colostrum densimeter) and the quantity (measured via a standard volume scale) of colostrum were measured within 30 min after the end of the CS. Fixed effects were fitted in mixed linear regression models to test for their potential association with colostrum quality (specific gravity; SG) and quantity (liters), and generalized mixed-effects models were constructed to test the associations of fixed effects with the optimal colostrum production index (yes vs no) based on an adequate supply of both colostrum quality and quantity. The fixed effects tested were parity, the gender of the calf, birth weight, duration of CS (min), and season of birth. Our results show that parity (primiparity), duration of CS (longer CS), and calving season (summer) had a significantly negative impact on colostrum production. Concluding, both colostrum quality and quantity can be influenced by intrinsic and extrinsic factors (including duration of CS), which should be considered while feeding newborn calves delivered via CS.