Expanding the clinical and genetic spectra of primary immunodeficiency-related disorders with clinical exome sequencing: expected and unexpected findings

Inmunodeficiencias primarias; Secuenciación de próxima generación; Secuenciación clínica del exomaImmunodeficiències primàries; Seqüenciació de propera generació; Seqüenciació clínica d’exomesPrimary immunodeficiencies; Next generation sequencing; Clinical exome sequencingPrimary immunodeficiencies (PIDs) refer to a clinically, immunologically, and genetically heterogeneous group of over 350 disorders affecting development or function of the immune system. The increasing use of next-generation sequencing (NGS) technology has greatly facilitated identification of genetic defects in PID patients in daily clinical practice. Several NGS approaches are available, from the unbiased whole exome sequencing (WES) to specific gene panels. Here, we report on a 3-year experience with clinical exome sequencing (CES) for genetic diagnosis of PIDs. We used the TruSight One sequencing panel, which includes 4,813 disease-associated genes, in 61 unrelated patients (pediatric and adults). The analysis was done in 2 steps: first, we focused on a virtual PID panel and then, we expanded the analysis to the remaining genes. A molecular diagnosis was achieved in 19 (31%) patients: 12 (20%) with mutations in genes included in the virtual PID panel and 7 (11%) with mutations in other genes. These latter cases provided interesting and somewhat unexpected findings that expand the clinical and genetic spectra of PID-related disorders, and are useful to consider in the differential diagnosis. We also discuss 5 patients (8%) with incomplete genotypes or variants of uncertain significance. Finally, we address the limitations of CES exemplified by 7 patients (11%) with negative results on CES who were later diagnosed by other approaches (more specific PID panels, WES, and comparative genomic hybridization array). In summary, the genetic diagnosis rate using CES was 31% (including a description of 12 novel mutations), which rose to 42% after including diagnoses achieved by later use of other techniques. The description of patients with mutations in genes not included in the PID classification illustrates the heterogeneity and complexity of PID-related disorders.This study was funded by Instituto de Salud Carlos III, grants PI14/00405 and PI17/00660, cofinanced by the European Regional Development Fund (ERDF)

A Delphi study to determine the European core curriculum for Master programmes in genetic counselling.

Genetic counsellors have been working in some European countries for at least 30 years. Although there are great disparities between the numbers, education, practice and acceptance of these professionals across Europe, it is evident that genetic counsellors and genetic nurses in Europe are working autonomously within teams to deliver patient care. The aim of this study was to use the Delphi research method to develop a core curriculum to guide the educational preparation of these professionals in Europe. The Delphi method enables the researcher to utilise the views and opinions of a group of recognised experts in the field of study; this study consisted of four phases. Phases 1 and 4 consisted of expert workshops, whereas data were collected in phases 2 and 3 (n=35) via online surveys. All participants in the study were considered experts in the field of genetic counselling. The topics considered essential for genetic counsellor training have been organised under the following headings: (1) counselling; (2) psychological issues; (3) medical genetics; (4) human genetics; (5) ethics, law and sociology; (6) professional practice; and (7) education and research. Each topic includes the knowledge, skills and attitudes required to enable genetic counsellors to develop competence. In addition, it was considered by the experts that clinical practice should comprise 50% of the educational programme. The core Master programme curriculum will enable current courses to be assessed and inform the design of future educational programmes for European genetic counsellors

Current status of genetic counselling for rare diseases in Spain

Genetic Counselling is essential for providing personalised information and support to patients with Rare Diseases (RD). Unlike most other developed countries, Spain does not recognize geneticists or genetic counsellors as healthcare professionals Thus, patients with RD face not only challenges associated with their own disease but also deal with lack of knowledge, uncertainty, and other psychosocial issues arising as a consequence of diagnostic delay. In this review, we highlight the importance of genetic counsellors in the field of RD as well as evaluate the current situation in which rare disease patients receive genetic services in Spain. We describe the main units and strategies at the national level assisting patients with RD and we conclude with a series of future perspectives and unmet needs that Spain should overcome to improve the management of patients with RD

Novel genes involved in severe early-onset obesity revealed by rare copy number and sequence variants

Obesity is a multifactorial disorder with high heritability (50-75%), which is probably higher in early-onset and severe cases. Although rare monogenic forms and several genes and regions of susceptibility, including copy number variants (CNVs), have been described, the genetic causes underlying the disease still remain largely unknown. We searched for rare CNVs (>100kb in size, altering genes and present in <1/2000 population controls) in 157 Spanish children with non-syndromic early-onset obesity (EOO: body mass index >3 standard deviations above the mean at <3 years of age) using SNP array molecular karyotypes. We then performed case control studies (480 EOO cases/480 non-obese controls) with the validated CNVs and rare sequence variants (RSVs) detected by targeted resequencing of selected CNV genes (n = 14), and also studied the inheritance patterns in available first-degree relatives. A higher burden of gain-type CNVs was detected in EOO cases versus controls (OR = 1.71, p-value = 0.0358). In addition to a gain of the NPY gene in a familial case with EOO and attention deficit hyperactivity disorder, likely pathogenic CNVs included gains of glutamate receptors (GRIK1, GRM7) and the X-linked gastrin-peptide receptor (GRPR), all inherited from obese parents. Putatively functional RSVs absent in controls were also identified in EOO cases at NPY, GRIK1 and GRPR. A patient with a heterozygous deletion disrupting two contiguous and related genes, SLCO4C1 and SLCO6A1, also had a missense RSV at SLCO4C1 on the other allele, suggestive of a recessive model. The genes identified showed a clear enrichment of shared co-expression partners with known genes strongly related to obesity, reinforcing their role in the pathophysiology of the disease. Our data reveal a higher burden of rare CNVs and RSVs in several related genes in patients with EOO compared to controls, and implicate NPY, GRPR, two glutamate receptors and SLCO4C1 in highly penetrant forms of familial obesity