scholarly journals Intrafamilial Phenotypic Variability Associated with the I1739V Mutation in the SCN9A Gene

2021 ◽  
pp. 135-139
Author(s):  
Leema Reddy Peddareddygari ◽  
Raji P. Grewal
Keyword(s):  
Sodium Channel ◽  
Phenotypic Variability ◽  
Small Fiber Neuropathy ◽  
Small Fiber ◽  
Congenital Insensitivity ◽  
Neurophysiological Studies ◽  
Phenotype Analysis ◽  
Congenital Insensitivity To Pain ◽  
Insensitivity To Pain ◽  
Intrafamilial Phenotypic Variability

The SCN9A gene encodes a voltage gated sodium channel Nav1.7 in which mutations can result in a wide variety of phenotypes ranging from congenital insensitivity to pain to small fiber neuropathy. We report the genotype phenotype analysis in a family carrying a specific mutation, I1739V, in the SCN9A gene. Neurophysiological studies have documented the gain of function impact of this mutation on this sodium channel. Interestingly, there is significant interfamilial phenotypic variability in individuals carrying this mutation. In our family, a father daughter combination had identical genotypes analyzing the SCN9A gene and multiple other genes known to cause neuropathy. Both of them carry the I1739V mutation but exhibit significant phenotypic variability with complaints of decreased sensitivity to discomfort in the father while the daughter has the clinical and laboratory features consistent with a small fiber neuropathy. We hypothesize that there are modifiers of the I1739V mutation that could involve intronic or exonic gene variants which contribute to this intrafamilial phenotypic variability. Our study has implications for genetic counseling, personalized medicine and the development of drugs to treat neuropathic pain.

Novel SCN9A Mutations in a Compound Heterozygous Girl with Congenital Insensitivity to Pain

2020 ◽  
Author(s):  
Bas Stunnenberg ◽  
Charlotte Haaxma ◽  
Mieke van Haelst ◽  
Maria Ponson-Wever ◽  
Eline Verberne ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Frameshift Mutation ◽  
Rare Disorder ◽  
Compound Heterozygous ◽  
Α Subunit ◽  
Voltage Gated ◽  
Congenital Insensitivity ◽  
Congenital Insensitivity To Pain ◽  
Insensitivity To Pain ◽  
Inactivating Mutations

AbstractCongenital Insensitivity to Pain (CIP) is a rare disorder that is characterized by the inability to perceive pain. It is caused by bi-allelic inactivating mutations in the SCN9A gene, which encodes the pore-forming α-subunit of the nerve voltage-gated sodium channel (Nav1.7). Patients with CIP are unable to feel pain from noxious stimuli, including heat, but all other peripheral somatosensory modalities function normally. Often anosmia is present as an additional feature. We report a patient with CIP caused by compound heterozygous SCN9A mutations: a novel in-frame deletion of exon 7 and a novel frameshift mutation. The identification of these mutations expands the spectrum of mutations associated with CIP.

scholarly journals Guided growth in the correction of knee deformity in patients with congenital insensitivity to pain

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Soroush Baghdadi ◽  
Sadegh Saberi ◽  
Taghi Baghdadi
Keyword(s):  
Demographic Data ◽  
Joint Destruction ◽  
Walking Ability ◽  
Guided Growth ◽  
Tertiary Referral Hospital ◽  
Common Procedure ◽  
Correction Rate ◽  
Congenital Insensitivity ◽  
Congenital Insensitivity To Pain ◽  
Insensitivity To Pain

Abstract Background Orthopedic manifestations of congenital insensitivity to pain (CIP) can be devastating if left untreated. Knee deformities are common in patients with CIP and might lead to joint destruction and loss of walking ability. The purpose of the present study was to report the results and complications of guided growth procedures around the knee in patients with CIP. Methods In a retrospective review, all patients with CIP who underwent guided growth procedures around the knee from 2009 to 2017 at a tertiary referral hospital were evaluated. Patients with secondary insensitivity to pain (e.g., syringomyelia), as well as patients with incomplete records, were excluded. Demographic data, clinical findings, correction rate, and complications were recorded. Results Ten knees in six patients fulfilled the inclusion criteria. The median age was 10 (range, 5–12), with a mean follow-up of 31 months (range, 16–56). Distal femoral tension-band hemiepiphysiodesis was the most common procedure, followed by proximal tibial hemiepiphysiodesis. The mean correction rate was 0.28°/month for femoral deformity. Staples were removed prematurely in one patient due to extrusion. No cases of infection or skin dehiscence were observed. None of the patients needed a reconstructive knee procedure during the study period. Conclusions The findings of this study suggest that guided growth procedures might have a role in the correction of knee deformities in patients with CIP. However, the correction rate is lower than that of typically developing children, patients should be closely followed to prevent complications, and stringent patient selection criteria should be followed to ensure success.

scholarly journals Identification of a novel nonsense mutation of the neurotrophic tyrosine kinase receptor type 1 gene in two siblings with congenital insensitivity to pain with anhidrosis

2017 ◽  
Vol 45 (2) ◽  
pp. 549-555 ◽  
Author(s):  
Ting Wang ◽  
Haibo Li ◽  
Jingjing Xiang ◽  
Bin Wei ◽  
Qin Zhang ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Nonsense Mutation ◽  
Mutation Screening ◽  
Receptor Type ◽  
Tyrosine Kinase Receptor ◽  
Site Mutation ◽  
Congenital Insensitivity ◽  
Congenital Insensitivity To Pain ◽  
Insensitivity To Pain

Objective To explore the aetiology of congenital insensitivity to pain with anhidrosis (CIPA) in two Chinese siblings with typical CIPA symptoms including insensitivity to pain, inability to sweat, and self-mutilating behaviours. Methods Clinical examination and genetic testing were conducted of all available family members, and the findings were used to create a pedigree. Mutation screening using PCR amplification and DNA Sanger sequencing of the entire neurotrophic tyrosine kinase receptor type 1 gene ( NTRK1) including intron–exon boundaries was used to identify mutations associated with CIPA. Results A novel nonsense mutation (c.7C > T, p. Arg3Ter) and a known splice-site mutation (c.851-33 T > A) were detected in NTRK1 and shown to be associated with CIPA. Conclusion Our findings expand the known mutation spectrum of NTRK1 and provide insights into the aetiology of CIPA.

NovelNTRK1mutations associated with congenital insensitivity to pain with anhidrosis verified by functional studies

2017 ◽  
Vol 22 (2) ◽  
pp. 92-99 ◽  
Author(s):  
Tai-Seung Nam ◽  
Wenting Li ◽  
Somy Yoon ◽  
Gwang Hyeon Eom ◽  
Myeong-Kyu Kim ◽  
...  
Keyword(s):  
Functional Studies ◽  
Congenital Insensitivity ◽  
Congenital Insensitivity To Pain ◽  
Insensitivity To Pain
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