NTRK1 c.1474G>A (p.Glu492Lys) has been reported as a homozygous variant in a patient with congenital sensory neuropathy, anhidrosis, seizures, deafness, and developmental delay, a phenotype consistent with congenital insensitivity to pain with anhidrosis (CIPA/HSAN4), which is exclusively caused by biallelic NTRK1 mutations.¹ Functional characterization of NTRK1 E492K in patient-derived iPSC neural stem cells demonstrated significantly reduced neurite outgrowth upon NGF treatment and markedly reduced NTRK1 gene expression compared to control cells; a conditional knock-in mouse model recapitulated altered TrkA signaling.² The variant co-segregates with disease in a multiplex family in which seven members had both ADTKD and mood disorders including five with bipolar disorder, providing evidence of co-segregation though with a phenotype that differs from classic NTRK1-related CIPA.³ The variant is present at low frequency in population databases: gnomAD v2.1 allele frequency 0.044% (124/282,262 alleles, 0 homozygotes) and gnomAD v4.1 allele frequency 0.069% (1,113/1,613,264 alleles, 1 homozygote), meeting PM2 at supporting level.⁴ In silico predictions support a deleterious effect: REVEL score 0.757 (damaging), PolyPhen-2 score 0.99 (probably damaging); SpliceAI max delta 0.08 indicates no splicing impact.⁵ One homozygous individual is observed in gnomAD v4.1, which for a fully penetrant severe autosomal recessive condition presenting at birth argues against complete penetrance; however, the phenotype of this individual is unknown and the variant may be hypomorphic.⁶ ClinVar classification is Uncertain Significance (Variation ID 418887, 7 submissions) with one Likely benign submission; no expert panel review exists.⁷ Overall balance of evidence: one moderate pathogenic criterion (PS3), four supporting pathogenic criteria (PM2, PP1, PP3, PP4), and one supporting benign criterion (BS2). This yields a net classification of Uncertain Significance per ACMG/AMP 2015 combination rules.⁸