Case Report: Congenital Insensitivity to Pain With Anhidrosis in a Lebanese Child With a Homozygous NTRK1 Splice-Region Variant and Heterozygous MEFV A744S: A Case Report

Background Congenital insensitivity to pain with anhidrosis (CIPA) is an inherited sensory and autonomic neuropathy most often associated with biallelic NTRK1 variants. Recurrent temperature elevation is common in CIPA, and an additional MEFV finding can complicate interpretation of these episodes. Case presentation A 2-year-old Lebanese boy born to consanguineous parents had markedly reduced pain responses from infancy, caregiver-reported anhidrosis, recurrent temperature episodes, self-injury, a hand burn, and a painless toe fracture. Brain magnetic resonance imaging and electrodiagnostic studies were normal. Whole-exome sequencing identified a homozygous NTRK1 splice-region variant and heterozygous MEFV A744S. Inflammatory markers were not obtained during attacks. After colchicine was started, his caregiver reported fewer temperature episodes. Conclusion The clinical phenotype, together with the homozygous NTRK1 splice-region variant, strongly supports CIPA, although the molecular classification of the variant remains uncertain. The heterozygous MEFV A744S finding and caregiver-reported response to colchicine raise the possibility of coexisting FMF but do not establish the diagnosis without a compatible inflammatory phenotype.