Evaluation of SHOX defects in the era of next‐generation sequencing

Short stature homeobox (SHOX) haploinsufficiency is a frequent cause of short stature. Despite advances in sequencing technologies, the identification of SHOX mutations continues to be performed using standard methods, including multiplex ligation‐dependent probe amplification (MLPA) followed by Sanger sequencing. We designed a targeted panel of genes associated with growth impairment, including SHOX genomic and enhancer regions, to improve the resolution of next‐generation sequencing for SHOX analysis. We used two software packages, CONTRA and Nexus Copy Number, in addition to visual analysis to investigate the presence of copy number variants (CNVs). We evaluated 15 patients with previously known SHOX defects, including point mutations, deletions and a duplication, and 77 patients with idiopathic short stature (ISS). The panel was able to confirm all known defects in the validation analysis. During the prospective evaluation, we identified two new partial SHOX deletions (one detected only by visual analysis), including an intragenic deletion not detected by MLPA. Additionally, we were able to determine the breakpoints in four cases. Our results show that the designed panel can be used for the molecular investigation of patients with ISS, and it may even detect CNVs in SHOX and its enhancers, which may be present in a significant fraction of patients.Copy number variants analyses and Sanger sequencing of breakpoint regions in Case 11, which has a heterozygous deletions involving exons 4, 5, and 6a of short stature homeobox (SHOX).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151254/1/cge13587.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151254/2/CGE_13587-sup-0001-Supinfo.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151254/3/cge13587_am.pd

Targeted massively parallel sequencing panel to diagnose genetic endocrine disorders in a tertiary hospital

Objectives: To analyze the efficiency of a multigenic targeted massively parallel sequencing panel related to endocrine disorders for molecular diagnosis of patients assisted in a tertiary hospital involved in the training of medical faculty. Material and methods: Retrospective analysis of the clinical diagnosis and genotype obtained from 272 patients in the Endocrine unit of a tertiary hospital was performed using a custom panel designed with 653 genes, most of them already associated with the phenotype (OMIM) and some candidate genes that englobes developmental, metabolic and adrenal diseases. The enriched DNA libraries were sequenced in NextSeq 500. Variants found were then classified according to ACMG/AMP criteria, with Varsome and InterVar. Results: Three runs were performed; the mean coverage depth of the targeted regions in panel sequencing data was 249×, with at least 96.3% of the sequenced bases being covered more than 20-fold. The authors identified 66 LP/P variants (24%) and 27 VUS (10%). Considering the solved cases, 49 have developmental diseases, 12 have metabolic and 5 have adrenal diseases. Conclusion: The application of a multigenic panel aids the training of medical faculty in an academic hospital by showing the picture of the molecular pathways behind each disorder. This may be particularly helpful in developmental disease cases. A precise genetic etiology provides an improvement in understanding the disease, guides decisions about prevention or treatment, and allows genetic counseling