Abstract: Objective Genetic testing and prenatal diagnosis were conducted in 18 congenital insensitivity to pain with anhidrosis(CIPA)families, laying the foundation for reducing the incidence of CIPA. Methods Genetic testing was performed using whole-genome sequencing and/or PCR-Sanger sequencing to identify candidate patho-genic variants in the probands. For deep intronic variants, the pathogenicity was validated through minigene assays, RT-PCR, Sanger sequencing, and co-segregation analysis. DNA extracted from chorionic villus or amniotic fluid cells was analyzed by PCR and Sanger sequencing to determine the genotype of the fetuses. Maternal DNA contamination was excluded by microsatellite allele genotyping. Additionally, multiplex ligation-dependent probe amplification (MLPA) was employed to detect common chromosomal aneuploidies. Results A total of 21 NTRK1 variants were identified across 18 CIPA pedigrees, including 9 missense variants, 2 nonsense variants, 5 frameshift variants, and 5 deep intronic variants. Among them, 3 were novel pathogenic variants. Prenatal genetic diagnosis was performed in 20 high-risk fetuses, revealing 2 normal fetuses, 12 carriers, and 6 affected with CIPA. Microsatellite genotyping confirmed the absence of maternal DNA contamination in fetal samples. Moreover, MLPA analysis excluded common chromosomal aneuploidies associated with syndromic conditions in all tested fetuses. Conclusions This study achieved a 100% molecular diagnosis rate in CIPA families, identified three novel pathogenic variants, and enabled the simultaneous prevention of CIPA and common chromosomal syndromes through integrated prenatal genetic testing, thereby providing critical insights for genetic counseling.

Key words: congenital insensitivity to pain with anhidrosis, NTRK1, variants, prenatal genetic diagnosis, genetic counseling