Expanding genetic and clinical aspects of Schwartz-Jampel syndrome: A report of two cases with literature review.

Schwartz-Jampel syndrome (SJS) is a rare autosomal recessive disorder characterized by muscle stiffness (myotonia) and chondrodysplasia. This disease is caused by biallelic loss of function mutations in the HSPG2 gene, which encodes the core protein of perlecan. This study aims to investigate causative variants in two sisters born to consanguineous Iranian parents. Both patients were presented with myotonia and a mask-like face; moreover, they showed a less common symptom, gastrointestinal bleeding, which is not typical of SJS and has only been reported in one patient. Regarding the crucial role of perlecan in vascular structure and mucosal stability, bleeding disorders could be expected in perlecan dysfunctions. In addition to the case study, a comprehensive literature review was conducted to gather information on similar genetic variants, associated clinical features, and possible disease mechanisms. Results of this study contribute to our understanding of the genetic and clinical aspects of Schwartz-Jampel syndrome, and more importantly, the manifestation of gastrointestinal bleeding in patients with Schwartz-Jampel syndrome.

Sealing faults and fluid-induced seismicity.

Sealing faults are nearly impermeable barriers that can form boundaries between subsurface pore-pressure domains. In hydrocarbon systems, sealing faults commonly form part of a structural trap; they are thus important elements for future storage of CO2 and other gases in depleted reservoirs. The Triassic Montney Formation in western Canada hosts low-permeability gas reservoirs containing sealing faults that have previously been assumed to compartmentalize pressure domains. In this study, we show that the distribution of induced seismicity associated with hydraulic fracturing (HF) exhibits a statistically significant spatial correlation with zones of high lateral gradient in pore pressure. These high-gradient zones are interpreted as sealing fault systems. The largest induced seismicity sequence, including a 4.5 ML mainshock on 30 November 2018, occurred during HF treatments in two horizontal wells, between which there is an exceptionally large contrast (~10 MPa) in measured pore pressure. Numerical simulation of a simplified model of a hydraulic fracture intersecting a nearby vertical fault, followed by fault rupture using rate-and-state friction rheology, generates results that are in good agreement with observed strike-slip faulting near one of the HF wells. Our study demonstrates that sealing faults exhibit previously unrecognized behaviour that may be important for understanding induced seismicity risk. This article is part of the theme issue 'Induced seismicity in coupled subsurface systems'.