Congenital insensitivity to pain and anhidrosis: Case report and review of findings along neuro-immune axis in the disorder

Congenital insensitivity to pain with anhidrosis: a literature review and the advocacy for stem cell therapeutic interventions

Congenital Insensitivity to Pain with Anhidrosis (CIPA) is a rare genetic disorder affecting the autonomic nervous system, leading to an inability to feel pain, temperature, or sweat1. This condition is caused by mutations in the NTRK1 gene, which encodes a receptor for nerve growth factor (NGF). The lack of NGF signaling results in the improper development and function of sensory and sympathetic neurons. Patients with CIPA often suffer from repeated injuries, infections, and hyperthermia due to their inability to sense pain and regulate body temperature. Management focuses on preventing injuries, controlling infections, and providing supportive care, as there is no definitive cure for CIPA. We present several hypotheses for treating CIPA using stem cells and modern genetic techniques. One approach involves using induced pluripotent stem cells (iPSCs) to replace defective neurons. Another hypothesis suggests in vivo gene editing of neural progenitors to restore TrkA function. Additionally, mesenchymal stem cells (MSCs) genetically modified to overexpress NGF could provide trophic support. Other strategies include epigenetic modulation of NTRK1 expression and exosome-mediated gene therapy. These innovative approaches aim to address the underlying genetic defects and restore normal cellular functions in CIPA patients.

A 5-Year-Old Palestinian Bedouin Girl with Repeated Self-Induced Injuries to the Digits, a Diagnosis of Congenital Insensitivity to Pain, and Anhidrosis

BACKGROUND Congenital insensitivity to pain with anhidrosis (CIPA), also referred to as hereditary sensory and autonomic neuropathy type IV, is a rare autosomal recessive disease caused by mutations in the NTRK1 gene. The inability to feel pain and temperature often leads to repeated severe and unintentional self-inflicted injuries; these can result in severe complications, as patients heal slowly from skin and bone injuries. This case report describes a 5-year-old Palestinian girl with self-inflicted injury to the digits, a dislocated distal inter-phalangeal joint of the left big toe, and a diagnosis of CIPA. CASE REPORT A 5-year-old girl, a daughter of related Palestinian Bedouin parents, presented with a chronic unhealed wound over the planter surface of the left foot. Painless repetitive minor traumata over the same area badly affected wound healing and this led to wound dehiscence and dislocation of the distal inter-phalangeal joint of the left big toe. Surgical fixation of the dislocated joint along with intravenous antibiotics and close follow-up resulted in eventual improvement and near complete wound healing despite the obviously slow healing process. The girl also displayed evidence of unintentional self-inflicted injury, which within the overall clinical context warranted a clinical suspicion of CIPA. This was confirmed by genetic testing for the presence of a homozygous frameshift mutation in the NTRK1 gene (c.1842_1843insT; p.Pro615Serfs*12). CONCLUSIONS This case report shows that a physician should have a low threshold of suspicion to investigate for CIPA when managing children with multiple unintentional self-inflicted injuries, anhidrosis, and pain insensitivity, mainly through genetic testing to detect mutations in the NTRK1 gene.

Clinical, genomics and networking analyses of a high-altitude native American Ecuadorian patient with congenital insensitivity to pain with anhidrosis: a case report

BACKGROUND

Congenital insensitivity to pain with anhidrosis (CIPA) is an extremely rare autosomal recessive disorder characterized by insensitivity to pain, inability to sweat and intellectual disability. CIPA is caused by mutations in the neurotrophic tyrosine kinase receptor type 1 gene (NTRK1) that encodes the high-affinity receptor of nerve growth factor (NGF).

CASE PRESENTATION

Here, we present clinical and molecular findings in a 9-year-old girl with CIPA. The high-altitude indigenous Ecuadorian patient presented several health problems such as anhidrosis, bone fractures, self-mutilation, osteochondroma, intellectual disability and Riga-Fede disease. After the mutational analysis of NTRK1, the patient showed a clearly autosomal recessive inheritance pattern with the pathogenic mutation rs763758904 (Arg602*) and the second missense mutation rs80356677 (Asp674Tyr). Additionally, the genomic analysis showed 69 pathogenic and/or likely pathogenic variants in 46 genes possibly related to phenotypic heterogeneity, including the rs324420 variant in the FAAH gene. The gene ontology enrichment analysis showed 28 mutated genes involved in several biological processes. As a novel contribution, the protein-protein interaction network analysis showed that NTRK1, SPTBN2 and GRM6 interact with several proteins of the pain matrix involved in the response to stimulus and nervous system development.

CONCLUSIONS

This is the first study that associates clinical, genomics and networking analyses in a Native American patient with consanguinity background in order to better understand CIPA pathogenesis.

A 10-year follow-up of asymptomatic Charcot hip joints caused by CIPA syndrome (congenital insensitivity to pain with anhidrosis) with failure of any surgical reconstructive treatment

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare genetic disorder. Patients with CIPA lack among other things the protective sensation of pain. Orthopaedic manifestations are fractures, infections and hip joint dislocation. We report a 10-year follow-up of late developing hip dysplasia with CIPA and the result of several reconstructive surgical procedures. The final outcome was asymptomatic Charcot hip joints with superior migration and dislocation of both hips without pain. In conformance with the literature standard operative techniques in these rare cases usually seem to fail. A multidisciplinary conservative approach with close observation and activity modification is the proposed treatment of choice.

Office-Based Anesthetic and Oral Surgical Management of a Child With Hereditary Sensory Autonomic Neuropathy Type IV: A Case Report

Hereditary sensory and autonomic neuropathy type IV (HSAN IV), or congenital insensitivity to pain with anhidrosis, is an exceptionally rare genetic disorder that results in the complete loss of pain and temperature sensation as well as anhidrosis. Anesthetic management of these patients can be difficult because of significantly increased risks during general anesthesia. Literature on perioperative anesthetic management is typically written in the context of a hospital setting. As such, our case presents a unique report on the anesthetic management of a HSAN IV patient who presented for extraction of 2 teeth in an office-based setting. In determining how to safely manage the procedure, we decided against general anesthesia as we lacked the facilities and equipment to safely handle previously reported complications. We were successful in providing sedation with nitrous oxide in oxygen and applying 20% benzocaine topical ointment on the surgical site in lieu of administering general anesthesia. We had an anesthesiologist present and obtained intravenous access prior to the surgery to help manage any complications. This report provides support that simple dental extractions can be accomplished safely in the HSAN IV patient in the office-based setting, thereby avoiding unnecessary risk.

Recurrent and novel mutations in the NTRK1 gene lead to rare congenital insensitivity to pain with anhidrosis in two Chinese patients

BACKGROUND

Congenital insensitivity to pain with anhidrosis (CIPA) is an extremely rare autosomal recessive autonomic and sensory neuropathy. CIPA is associated with various mutations in NTRK1.

CASES

Two unrelated Chinese patients presented separately with symptoms of insensitivity to pain, inability to sweat, repeated painless fractures, and Charcot arthropathy were recruited. Both of them were clinically diagnosed with CIPA. Increased serum bone resorption marker (β-CTX) levels and decreased BMD were observed in both patients. X-ray films revealed enlarged bony calli in the fracture sites, Charcot arthropathy, and bilateral lower limb osteomyelitis. Sanger sequencing demonstrated compound heterozygous mutations in NTRK1 for proband 1 (IVS7-33T>A in intron 7 and c. 2281C>T in exon 17) and for proband 2 (IVS7-33T>A in intron 7 and c.1652delA in exon 14), of which the variation in exon 14 in NTRK1 was a novel mutation.

CONCLUSIONS

We report the detailed phenotypes, as well as both recurrent and novel mutations in NTRK1 in 2 Chinese patients with CIPA. The genetic findings of our study expand the gene mutation spectrum of CIPA.