Case Report Visceral Leishmaniasis in a UK Toddler following a Short Trip to a Popular Holiday Destination in Spain

We herein present the case of a 15-month-old with visceral leishmaniasis diagnosed in the UK following a short trip to a popular holiday destination in Spain. Four months after the initial symptoms, the diagnosis was made incidentally on microscopy of a bone marrow biopsy taken for suspected haematological malignancy after the child developed hepatosplenomegaly, pancytopaenia, and Klebsiella pneumoniae septicaemia

Do twins share the same dress code?:Quantifying relative genetic and environmental contributions to subjective perceptions of "the dress" in a classical twin study

The phenomenon of contrasting color perceptions of "the dress" photograph has gained scientific interest. The mechanism underlying why individuals differ is yet to be fully explained. We use the powerful twin model design to ascertain the relative contribution of genetic and environmental factors on perception variation. A sample of 466 twins from the British TwinsUK registry were invited to report what color they saw in a standard image of the dress in standard illumination. The mean age of the participants was 49.5 (SD = 17.8) years, and 85% were female. When asked to choose between white and gold (WG) or blue and black (BB), 328 reported WG (70.4%) and 135 (29.0%) reported BB. Subjects choosing WG were significantly older (p < 0.01), but there was no significant difference in gender. Monozygotic (MZ) twins were more concordant in their responses than dizygotic (DZ) twins (0.46 vs. 0.36). Twin modeling revealed that genetic factors accounted for 34% (95% confidence interval, 5%-59%) of variation in the reported color of the dress when adjusted for age, whereas environmental factors contributed 66% (95% CI, 41%-95%). This study suggests environmental factors play a significant role in how an individual perceives the color of "the dress.

Visceral Leishmaniasis in a UK Toddler following a Short Trip to a Popular Holiday Destination in Spain

We herein present the case of a 15-month-old with visceral leishmaniasis diagnosed in the UK following a short trip to a popular holiday destination in Spain. Four months after the initial symptoms, the diagnosis was made incidentally on microscopy of a bone marrow biopsy taken for suspected haematological malignancy after the child developed hepatosplenomegaly, pancytopaenia, and Klebsiella pneumoniae septicaemia

Electrical responses from human retinal cone pathways associate with a common genetic polymorphism implicated in myopia

Myopia is the commonest visual impairment. Several genetic loci confer risk, but mechanisms by which they do this are unknown. Retinal signals drive eye growth, and myopia usually results from an excessively long eye. The common variant most strongly associated with myopia is near the GJD2 gene, encoding connexin-36, which forms retinal gap junctions. Light-evoked responses of retinal neurons can be recorded noninvasively as the electroretinogram (ERG). We analyzed these responses from 186 adult twin volunteers who had been genotyped at this locus. Participants underwent detailed ERG recordings incorporating international standard stimuli as well as experimental protocols aiming to separate dark-adapted rod- and cone-driven responses. A mixed linear model was used to explore association between allelic dosage at the locus and international standard ERG parameters after adjustment for age, sex, and family structure. Significant associations were found for parameters of light-adapted, but not dark-adapted, responses. Further investigation of isolated rod- and cone-driven ERGs confirmed associations with cone-driven, but not rod-driven, a-wave amplitudes. Comparison with responses to similar experimental stimuli from a patient with a prior central retinal artery occlusion, and from two patients with selective loss of ON-bipolar cell signals, was consistent with the associated parameters being derived from signals from cone-driven OFF-bipolar cells. Analysis of single-cell transcriptome data revealed strongest GJD2 expression in cone photoreceptors; bipolar cell expression appeared strongest in OFF-bipolar cells and weakest in rod-driven ON-bipolar cells. Our findings support a potential role for altered signaling in cone-driven OFF pathways in myopia development