Unexpected complexity in the molecular diagnosis of spastic paraplegia 11.

Background: Spastic paraplegia 11 (SPG11) is the most prevalent form of autosomal recessive hereditary spastic paraplegia, resulting from biallelic pathogenic variants in the SPG11 gene (MIM *610844).

Methods: The proband is a 36-year-old female referred for genetic evaluation due to cognitive dysfunction, gait impairment, and corpus callosum atrophy (brain MRI was normal at 25-years-old). Diagnostic approaches included CGH array, next-generation sequencing, and whole transcriptome sequencing.

The Genetic Landscape of Inherited Retinal Diseases in a Mexican Cohort: Genes, Mutations and Phenotypes.

In this work, we aimed to provide the genetic diagnosis of a large cohort of patients affected with inherited retinal dystrophies (IRDs) from Mexico. Our data add valuable information to the genetic portrait in rare ocular diseases of Mesoamerican populations, which are mostly under-represented in genetic studies. A cohort of 144 unrelated probands with a clinical diagnosis of IRD were analyzed by next-generation sequencing using target gene panels (overall including 346 genes and 65 intronic sequences).

Scaling New Heights in the Genetic Diagnosis of Inherited Retinal Dystrophies.

During the last 20 years, our group has focused on identifying the genes and mutations causative of inherited retinal dystrophies (IRDs). By applying massive sequencing approaches (NGS) in more than 500 familial and sporadic cases, we attained high diagnostic efficiency (85%) with a custom target gene panel and over 75% using whole exome sequencing (WES). Close to 40% of pathogenic alleles are novel mutations, which demand specific in silico tests and in vitro assays.

Aberrant Splicing Events Associated to Noncanonical Splice Site Mutations in a Proband with Atypical Usher Syndrome 1.

Aims: The aim of this study was the genetic diagnosis by next generation sequencing (NGS) of a patient diagnosed with Usher syndrome type 2 and the functional evaluation of the identified genetic variants to establish a phenotype-genotype correlation.

Methods: Whole exome sequencing (WES) analysis identified two heterozygous intronic variants in , a gene responsible of Usher syndrome type 1. Evaluation of the putative splicing effects was performed in vivo, in whole blood samples, and in vitro, by transfection of midigene constructs in HEK293T cells.

Novel mutation in the choroideremia gene and multi-Mendelian phenotypes in Spanish families.

Aims: We aimed to accurately diagnose several retinitis pigmentosa (RP) patients with complex ocular phenotypes by combining massive sequencing genetic diagnosis and powerful clinical imaging techniques.

Methods: Whole-exome sequencing (WES) of selected patients from two RP families was undertaken. The variants identified were validated by Sanger sequencing and cosegregation analysis.

Novel Candidate Genes and a Wide Spectrum of Structural and Point Mutations Responsible for Inherited Retinal Dystrophies Revealed by Exome Sequencing.

Background: NGS-based genetic diagnosis has completely revolutionized the human genetics field. In this study, we have aimed to identify new genes and mutations by Whole Exome Sequencing (WES) responsible for inherited retinal dystrophies (IRD).

Methods: A cohort of 33 pedigrees affected with a variety of retinal disorders was analysed by WES.

Combined genetic and high-throughput strategies for molecular diagnosis of inherited retinal dystrophies.

Most diagnostic laboratories are confronted with the increasing demand for molecular diagnosis from patients and families and the ever-increasing genetic heterogeneity of visual disorders. Concerning Retinal Dystrophies (RD), almost 200 causative genes have been reported to date, and most families carry private mutations. We aimed to approach RD genetic diagnosis using all the available genetic information to prioritize candidates for mutational screening, and then restrict the number of cases to be analyzed by massive sequencing.

Molecular genetic analysis of retinitis pigmentosa in Indonesia using genome-wide homozygosity mapping.

Purpose: Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous retinal disorder. Despite tremendous knowledge about the genes involved in RP, little is known about the genetic causes of RP in Indonesia. Here, we aim to identify the molecular genetic causes underlying RP in a small cohort of Indonesian patients, using genome-wide homozygosity mapping.

High transcriptional complexity of the retinitis pigmentosa CERKL gene in human and mouse.

Purpose: To shed light on the pathogenicity of the mutations in the retinitis pigmentosa gene CERKL, the authors aimed to characterize its transcriptional repertoire and focused on the use of distinct promoters and alternative splicing in human and mouse tissues.

Methods: In silico genomic and transcriptomic computational customized analysis, combined with experimental RT-PCRs on different human and murine tissues and cell lines and immunohistochemistry, have been used to characterize the transcriptional spectrum of CERKL. In the mouse retina, Cerkl is detected primarily in ganglion cells and cones but can also be observed in rods.

High-resolution homozygosity mapping is a powerful tool to detect novel mutations causative of autosomal recessive RP in the Dutch population.

Purpose: To determine the genetic defects underlying autosomal recessive retinitis pigmentosa (arRP) in the Dutch population and in a subset of patients originating from other countries. The hypothesis was that, because there has been little migration over the past centuries in certain areas of The Netherlands, a significant fraction of Dutch arRP patients carry their genetic defect in the homozygous state.

Methods: High-resolution genome-wide SNP genotyping on SNP arrays and subsequent homozygosity mapping were performed in a large cohort of 186 mainly nonconsanguineous arRP families living in The Netherlands.

A novel nonsense mutation in CEP290 induces exon skipping and leads to a relatively mild retinal phenotype.

PURPOSE. To identify the genetic defect in a family with variable retinal phenotypes. The proband had a diagnosis of Leber congenital amaurosis (LCA), whereas her two cousins had an early-onset severe retinal dystrophy (EOSRD) with useful vision.