Next generation diagnostics of heritable connective tissue disorders

Abstract

Finding pathogenic mutations in monogenic diseases represents one of the significant milestones of late 20th century molecular genetics. Mutation data can improve genetic counseling, assist disease modeling and provide a basis for translational research and therapeutics. The logistics of detecting disease mutations, however, has not always been easy or straightforward. Traditional approaches using genetic linkage or candidate gene analysis have often been laborious and expensive, but the advent of next generation sequencing technologies is changing the very nature of modern-day gene discovery and mutation detection. The application of whole-exome and whole-genome sequencing has demonstrated how these new approaches can improve diagnostic sensitivity as well as disclose completely novel and unsuspected disease-gene associations. Use of next generation sequencing in inherited diseases that display genetic heterogeneity is already a cost-effective methodology for mutation detection. Further reductions in sequencing costs and machine run time, as well as improved bioinformatics, are likely to lead to the incorporation of next generation sequencing into routine diagnostics within clinical genetics. In the short term, the impact of next generation sequencing on the genetically diverse and clinically protean heritable connective tissue disorders is likely to mean more comprehensive documentation of individual mutations. Longer term, dissection of bioinformatics data may lead to further insight into individual prognosis and an era of new personal therapeutics.

Whole-exome sequencing improves mutation detection in a diagnostic epidermolysis bullosa laboratory

“…One new technology that could potentially improve sensitivity in EB diagnostics is next‐generation sequencing (NGS), in which the whole genome or a portion thereof is sequenced . NGS has proven very useful for identifying novel genetic variants responsible for Mendelian disorders, including a new form of EBS .…”

Candidate prognostic markers in breast cancer: focus on extracellular proteases and their inhibitors

“…In fact, collagen is the most abundant protein across the animal kingdom, serving to provide tissues with strength and resilience 11. Accordingly, there are many diseases that stem directly from defects in collagen production and homeostasis, either from underlying genetic alterations and/or abnormal collagen processing (eg, osteogenesis imperfecta, Alport syndrome, Ehlers–Danlos syndrome) 12. In addition, the integrity of collagen in the ECM plays a key role in cancer – the active degradation of type IV collagen by extracellular proteases facilitates tumor cell invasion through the basement membrane 13.…”

Dermatopathology – the link between ancillary techniques and clinical lesions

“…NGS is still expensive and requires expertise in handling large data outcome and thus is currently still mostly limited to research settings. However, it has found its way into diagnostics in human medicine . In veterinary medicine, the genomes of many species have still not been sequenced, which limits the use of this method.…”

“…It can be performed on the entire genome, which includes noncoding areas of the DNA (introns), coding areas of the DNA (exons) and mitochondrial DNA, or limited to coding areas of the genome. The former is referred to as whole‐genome sequencing (WGS), whereas the latter is referred to as whole‐exome sequencing (WES) . The exome involves roughly 1.5% of the human genome, encompassing most exons of about 20,000 human genes; WES is therefore less labour‐intensive than WGS .…”

“…The former is referred to as wholegenome sequencing (WGS), whereas the latter is referred to as whole-exome sequencing (WES). 85,86 The exome involves roughly 1.5% of the human genome, encompassing most exons of about 20,000 human genes; WES is therefore less labour-intensive than WGS. 87 WES involves enrichment procedures, such as exome enrichment and, thus, RNA sequencing, also called whole transcriptome analysis or whole transcriptome shotgun sequencing (WTSS), may often be used as an alternative approach to detect variability in protein-coding regions.…”