NGS and phenotypic ontology-based approaches increase the diagnostic yield in syndromic retinal diseases.

Syndromic retinal diseases (SRDs) are a group of complex inherited systemic disorders, with challenging molecular underpinnings and clinical management. Our main goal is to improve clinical and molecular SRDs diagnosis, by applying a structured phenotypic ontology and next-generation sequencing (NGS)-based pipelines. A prospective and retrospective cohort study was performed on 100 probands with an a priori diagnosis of non-Usher SRDs, using available clinical data, including Human Phenotype Ontology annotation, and further classification into seven clinical categories (ciliopathies, specific syndromes and five others). Retrospective molecular diagnosis was assessed using different molecular and bioinformatic methods depending on availability. Subsequently, uncharacterized probands were prospectively screened using other NGS approaches to extend the number of analyzed genes. After phenotypic classification, ciliopathies were the most common SRD (35%). A global characterization rate of 52% was obtained, with six cases incompletely characterized for a gene that partially explained the phenotype. An improved characterization rate was achieved addressing prospective cases (83%) and well-recognizable syndrome (62%) subgroups. The 27% of the fully characterized cases were reclassified into a different clinical category after identification of the disease-causing gene. Clinical-exome sequencing is the most appropriate first-tier approach for prospective cases, whereas whole-exome sequencing and bioinformatic reanalysis increases the diagnosis of uncharacterized retrospective cases to 45%, mostly those with unspecific symptoms. Our study describes a comprehensive approach to SRDs in daily clinical practice and the importance of thorough clinical assessment and selection of the most appropriate molecular test to be used to solve these complex cases and elucidate novel associations.

Barium sulphate and soft-tissue radiology: allying the old and the new for the investigation of animal cutaneous microcirculation.

The study of microcirculation using angiography is essential to the advancement of flap and angiogenesis research in plastic surgery. Until the mid-1980s, barium sulphate was the most commonly used contrast material, although it did not provide optimal visualisation of the vascular tree. In 1986, a new technique using lead oxide was proposed, which permitted very high-quality imaging and rapidly became the technique of choice, despite its high toxicity. We reconsider the former technique of barium-sulphate injection and combine it with soft-tissue radiology using mammographic film to achieve a radiological definition similar to that obtained with lead oxide, and discuss the advantages and disadvantages of the two methods. We conclude that barium sulphate and the use of mammographic film is an accurate, simple and non-toxic method of analysing the cutaneous circulation in small animals.