High-throughput sequencing of the entire genomic regions of CCM1/KRIT1, CCM2 and CCM3/PDCD10 to search for pathogenic deep-intronic splice mutations in cerebral cavernous malformations.

Cerebral cavernous malformations (CCM) are vascular lesions of the central nervous system that can cause headaches, seizures and hemorrhagic stroke. Disease-associated mutations have been identified in three genes: CCM1/KRIT1, CCM2 and CCM3/PDCD10. The precise proportion of deep-intronic variants in these genes and their clinical relevance is yet unknown. Here, a long-range PCR (LR-PCR) approach for target enrichment of the entire genomic regions of the three genes was combined with next generation sequencing (NGS) to screen for coding and non-coding variants. NGS detected all six CCM1/KRIT1, two CCM2 and four CCM3/PDCD10 mutations that had previously been identified by Sanger sequencing. Two of the pathogenic variants presented here are novel. Additionally, 20 stringently selected CCM index cases that had remained mutation-negative after conventional sequencing and exclusion of copy number variations were screened for deep-intronic mutations. The combination of bioinformatics filtering and transcript analyses did not reveal any deep-intronic splice mutations in these cases. Our results demonstrate that target enrichment by LR-PCR combined with NGS can be used for a comprehensive analysis of the entire genomic regions of the CCM genes in a research context. However, its clinical utility is limited as deep-intronic splice mutations in CCM1/KRIT1, CCM2 and CCM3/PDCD10 seem to be rather rare.

Hydrogen sulphide and the kidney: important roles in renal physiology and pathogenesis and treatment of kidney injury and disease.

The kidney is an essential mammalian organ that serves to filter toxins and metabolic by-products out of the blood, which are then excreted through urine. Hydrogen sulphide (H2S) is a recently characterized, endogenous gaseous molecule with important physiological roles. Many interesting roles continue to be identified for H2S related specifically to the kidney. The current review discusses how production and action of H2S influences normal physiology of the kidney. We investigate as well the many roles H2S plays in the pathogenesis and treatment of kidney injury and disease, such as chronic kidney disease (CKD), ureteral obstruction (UO), hyperhomocysteinaemia (HHcy), drug-induced nephrotoxicity (DIN) and renal ischaemia reperfusion injury (IRI). We suggest that H2S plays a complex and essential role in the normal function of the kidney and dysregulation of H2S production can directly or indirectly contribute to the pathogenesis of renal disease and injury. Also, H2S could be a promising potential therapeutic treatment to decrease the severity of several renal diseases. Further research will identify increasingly important and complex roles for H2S in renal physiology and how H2S can be effectively utilized to improve clinical outcomes of renal disease.