Analysis of KRT5 and KRT14 gene mutations and mode of inheritance in Iranian patients with clinical suspicion of Epidermolysis bullosa simplex

Background: Epidermolysis bullosa simplex is a hereditary skin disorder caused by mutations in several genes such as KRT5 and KRT14. Skin fragility in basal keratinocytes presence regions led to the cytolysis of epidermis and blistering. Aim of this study was to detect the molecular defects in KRT5 and KRT14 genes hot spots in patients with clinical suspicion of EBS and investigation of their probable genotype-phenotype correlations. Methods: Exons 1 and 6-7 of KRT5 and exons 1 and 4-7 of KRT14 amplification and mutation detection were performed by polymerase chain reaction and Sanger sequencing, respectively. Novel variants pathogenicity evaluated by bioinformatics tools. Results: Nine important variants detected in seven different patients within 6 Iranian families affected by Epidermolysis bullosa simplex, of which four variants were novel. Three patients had a mottled pigmentation phenotype G96D (p. Gly96Asp) and F97I (p. Phe97Ile) in KRT5. One of them showed a Dowling-Meara phenotype A417P (p. Ala417Pro) and E477D (p. Glu477Asp) in KRT5 and another had a Koebner type phenotype R397I (p. Arg397Ile) and Q444* (p. Gln444Ter) in KRT5. A novel variant G92E (p. Gly92Glu) in KRT5 in a double heterozygous state with a challenging variant A413T (p. Ala413Thr) in KRT14 identified in one patient with Koebner type phenotype. Also, a previously reported mutation I377T (p. Ile377Thr) in KRT14 gene identified in this study. Conclusion: The results of molecular data analysis showed that the most severe phenotypes were associated with mutations in highly conserved regions. In some cases, different inheritance modes were observed. © Iran University of Medical Sciences

Calcium Homeostasis and Cone Signaling Are Regulated by Interactions between Calcium Stores and Plasma Membrane Ion Channels

Calcium is a messenger ion that controls all aspects of cone photoreceptor function, including synaptic release. The dynamic range of the cone output extends beyond the activation threshold for voltage-operated calcium entry, suggesting another calcium influx mechanism operates in cones hyperpolarized by light. We have used optical imaging and whole-cell voltage clamp to measure the contribution of store-operated Ca2+ entry (SOCE) to Ca2+ homeostasis and its role in regulation of neurotransmission at cone synapses. Mn2+ quenching of Fura-2 revealed sustained divalent cation entry in hyperpolarized cones. Ca2+ influx into cone inner segments was potentiated by hyperpolarization, facilitated by depletion of intracellular Ca2+ stores, unaffected by pharmacological manipulation of voltage-operated or cyclic nucleotide-gated Ca2+ channels and suppressed by lanthanides, 2-APB, MRS 1845 and SKF 96365. However, cation influx through store-operated channels crossed the threshold for activation of voltage-operated Ca2+ entry in a subset of cones, indicating that the operating range of inner segment signals is set by interactions between store- and voltage-operated Ca2+ channels. Exposure to MRS 1845 resulted in ∼40% reduction of light-evoked postsynaptic currents in photopic horizontal cells without affecting the light responses or voltage-operated Ca2+ currents in simultaneously recorded cones. The spatial pattern of store-operated calcium entry in cones matched immunolocalization of the store-operated sensor STIM1. These findings show that store-operated channels regulate spatial and temporal properties of Ca2+ homeostasis in vertebrate cones and demonstrate their role in generation of sustained excitatory signals across the first retinal synapse

Investigating the Challenges Facing Mentally Retarded Adolescents in Acquiring Self-Empowerment Skills

Background and Aim: Disability is a global phenomenon that has been discussed in all societies throughout history, so that 10% of the world's population is physically, mentally, psychologically, and socially disabled according to the World Health Organization (WHO). So, officials and macro-policymakers in the field of the disabled should provide appropriate conditions to promote the mental health of families with children with special disabilities by taking the necessary measures. Accordingly, this study was conducted to identify the challenges facing mentally retarded adolescents in acquiring self-empowerment skills. Methods: This is a qualitative study based on the nature of the data and a baseline study in terms of the type of theory. The statistical population included specialists and practitioners working in centers for the education and care of mentally retarded adolescents, mothers, and caregivers who were selected by purposive sampling in Tehran in 2019. Data were collected through semi-structured 35- to 45-minute interviews to reach saturation with 15 specialists and 10 mothers and caregivers. Data were analyzed by the method developed by Strauss and Corbin. Results: According to the results, the challenges in acquiring self-empowerment skills in mentally retarded adolescents could be classified as parental ignorance, rejection, economic, social, and family constraints, abuse/harassment, feelings of inadequacy, inefficiency, Inadequate professional and welfare support, social inequality, lack of enforcement of laws, lack of jobs concerning disability, educational malfunctions, and lack of qualified trainers. Conclusion: The results showed that a lack of awareness of the abilities and potentials of mentally retarded adolescents in acquiring self-empowerment skills creates challenges for them to achieve this goal. So, special attention should be paid to mentally retarded adolescents and careful consideration of the challenges they face in acquiring self-improvement skills. This can lead to solutions to increase their social skills, life skills, and self-empowerment

CTNS molecular genetics profile in a Persian nephropathic cystinosis population

Purpose: In this report, we document the CTNS gene mutations of 28 Iranian patients with nephropathic cystinosis age 1–17 years. All presented initially with severe failure to thrive, polyuria, and polydipsia. Methods: Cystinosis was primarily diagnosed by a pediatric nephrologist and then referred to the Iran University of Medical Sciences genetics clinic for consultation and molecular analysis, which involved polymerase chain reaction (PCR) amplification to determine the presence or absence of the 57-kb founder deletion in CTNS, followed by direct sequencing of the coding exons of CTNS. Results: The common 57-kb deletion was not observed in any of the 28 Iranian patients. In 14 of 28 patients (50%), mutations were observed in exons 6 and 7. No mutation was detected in exon 5, and only one (3.6%) patient with cystinosis showed a previously reported 4-bp deletion in exon 3 of CTNS. Four patients (14.3%) had a previously reported mutation (c.969C>A; p.N323K) in exon 11, and five (18%) had novel homozygous deletions in exon 6 leading to premature truncation of the protein. These deletions included c.323delA; p.Q108RfsX10 in three individuals and c.257-258delCT; p.S86FfsX37 in two cases. Other frame-shift mutations were all novel homozygous single base pair deletion/insertions including one in CTNS exon 9 (c.661insT; p.V221CfsX6), and four (14.3%) in exon 4, i.e., c.92insG; p.V31GfsX28 in two and c.120delC; p.T40TfsX10 in two. In total, we identified eight previously reported mutations and eight novel mutations in our patients. The only detected splice site mutation (IVS3-2A>C) was associated with the insertion mutation in the exon 9. Conclusion: This study, the first molecular genetic analysis of non-ethnic-specific Iranian nephropathic cystinosis patients, may provide guidance for molecular diagnostics of cystinosis in Iran