A Novel Large Deletion in the EVER1 Gene in a Family With Epidermodysplasia Verruciformis From India.

ABSTRACT: Epidermodysplasia verruciformis (EV) is a rare autosomal recessive genodermatosis due to mutations in EVER1 and EVER2 genes. The genetic profile of Indian patients with EV has not been previously studied. This report describes the clinical presentation and molecular analysis of a family with EV. Using genomic DNA from two affected probands and healthy controls (two other siblings), conventional polymerase chain reaction (PCR) was conducted with novel primer sets designed to amplify the coding and splice-site regions in the genes EVER1 and EVER 2. This revealed no amplification with a primer set for exons 16 to 18 in the EVER1 gene of both the probands. Subsequently, long-range PCR spanning the length of exon 15-20 and next-generation sequencing demonstrated a homozygous deletion of 2078 bp in the EVER1 gene (EVER1:c.2072_2278del). Screening the family revealed the same homozygous deletion (similar to index cases) in two other affected siblings. The parents and two asymptomatic siblings were heterozygous carriers for the deletion while one healthy sibling was negative. These results were validated with Sanger sequencing. This deletion in exons 17 and 18 of the EVER1 gene results in a frameshift, followed by a premature termination resulting in a severe phenotype. The identification and validation of this large deletion was detected using stepwise amplicon-based target enrichment and long-range PCR, respectively. In this family, this simple strategy greatly enhanced genetic counseling as well as early genetic diagnosis and screening. However, functional assays and larger studies are required to characterize and validate the genetic diversity among Indians with EV.

Magnetic Stress-Driven Metal-Insulator Transition in Strongly Correlated Antiferromagnetic CrN.

Traditionally, the Coulomb repulsion or Peierls instability causes the metal-insulator phase transitions in strongly correlated quantum materials. In comparison, magnetic stress is predicted to drive the metal-insulator transition in materials exhibiting strong spin-lattice coupling. However, this mechanism lacks experimental validation and an in-depth understanding. Here we demonstrate the existence of the magnetic stress-driven metal-insulator transition in an archetypal material, chromium nitride. Structural, magnetic, electronic transport characterization, and first-principles modeling analysis show that the phase transition temperature in CrN is directly proportional to the strain-controlled anisotropic magnetic stress. The compressive strain increases the magnetic stress, leading to the much-coveted room-temperature transition. In contrast, tensile strain and the inclusion of nonmagnetic cations weaken the magnetic stress and reduce the transition temperature. This discovery of a new physical origin of metal-insulator phase transition that unifies spin, charge, and lattice degrees of freedom in correlated materials marks a new paradigm and could lead to novel device functionalities.

Thermal conductivity of free-standing silicon nanowire using Raman spectroscopy.

Low dimensional systems, nanowires (NWs), in particular, have exhibited excellent optical and electronic properties. Understanding the thermal properties in semiconductor NWs is very important for their applications in electronic devices. In the present study, the thermal conductivity of a freestanding silicon NW is estimated by employing Raman spectroscopy. The advantage of this technique is that the excitation source (laser) acts as both the heater and probe. The variations of the first-order Raman peak position of the freestanding silicon NW with respect to temperature and laser power are recorded. From the analysis of effective laser power absorbed by exposed silicon NW and a detailed Raman study along with the concept of longitudinal heat distribution in silicon NW, the thermal conductivity of the freestanding silicon NW of ∼112 nm diameter is estimated to be ∼53 W m-1 K- 1.

Extramedullary plasmacytoma: an unusual neoplasm in a HIV-positive patient.

There is a wide range of plasma cell abnormalities in people living with HIV (PLHIV). Extramedullary plasmacytomas are not common in HIV infection, unlike plasmablastic lymphomas. An HIV-positive 44-year-old man on antiretroviral therapy presented with a rapidly progressing swelling on the face. Imaging revealed underlying bone destruction. Histologically, there was a tumour composed of small to medium-sized plasmacytoid cells admixed with many mature plasma cells and plasmablasts. These were positive for CD138 and MUM 1. Extramedullary multiple myeloma was ruled out as CD56 and cyclin D-1 were negative. EBV was negative. As the tumour cells were mostly mature, plasmablastic lymphoma was also excluded. The presence of a monoclonal protein (1 g%), IgG kappa type, was detected. Neoplasia of plasma cells acquires special clinical characteristics in PLHIV. These patients are younger, with a greater tendency to develop solitary extramedullary plasmacytomas with atypical clinical evolution and greater aggressiveness of the neoplastic process. All of these features, along with a high proliferation index (MIB1 60%) was found in our patient. We report this case for its rarity, histopathological dilemma and its atypical features in HIV infection.