OBJECTIVETo screen for mutations of NTRK1 gene in a Chinese family affected with congenital insensitivity to pain with anhidrosis (CIPA).

METHODSGenomic DNA was extracted from the proband and her family members. All of the 17 exons and intron-exon boundaries of the NTRK1 gene were analyzed by direct Sanger sequencing. For the deletional mutation, the PCR products were subjected to T-A cloning and sequencing to verify the mutation.

RESULTSNTRK1 gene analysis revealed that proband has carried a c.1786C>T (p.Arg596*) nonsense mutation inherited from her mother and a novel deletional mutation c.1928-2028+23del from her father. Her elder brother only carried the deletional mutation.

CONCLUSIONThe diagnosis of CIPA relied on typical clinical symptoms of no pain, anhidrosis and intellectual disability and detection of the biallelic NTRK1 mutations. The novel deletional mutation has enriched the spectrum of NTRK1 mutations.

Child, Preschool ; DNA Mutational Analysis ; Exons ; Female ; Hereditary Sensory and Autonomic Neuropathies ; diagnosis ; genetics ; Humans ; Mutation ; Receptor, trkA ; genetics

OBJECTIVE: To explore the genetic variation of a Chinese family affected with congenital insensitivity to pain with anhidrosis and albinism. METHODS: Whole exome sequencing (WES) was carried out to screen potential variants within genomic DNA extracted from the proband and his parents. Whole genome sequencing (WGS) was applied when variants were not found completely. Suspected variants were validated by Sanger sequencing. RESULTS: WES has identified a heterozygous c.1729G>C (p.G577R) variant of NTRK1 gene and two heterozygous variants of OCA2 gene, namely c.1363A>G (p.R455G) and c.1182+1G>A. WGS has identified two additional heterozygous variants c.(851-798C>T; 851-794C>G) in deep intronic regions of the NTRK1 gene. CONCLUSION The compound heterozygous variants of the NTRK1 gene probably underlay the congenital insensitivity to pain with anhidrosis. And the compound heterozygous variants of the OCA2 gene probably underlay the albinism in the proband. In the case where no variant is detected by WES in the coding region, WGS should be considered to screen potential variants in the whole genome.
Albinism ; Child ; DNA Mutational Analysis ; Hereditary Sensory and Autonomic Neuropathies/genetics* ; Heterozygote ; Humans ; Membrane Transport Proteins ; Mutation ; Pedigree

OBJECTIVETo screen for mutations in the neurotrophic tyrosine kinase receptor type 1 (NTRK1) gene in a Chinese family affected with congenital insensitivity to pain with anhidrosis (CIPA).

METHODSWith informed consent obtained, peripheral blood samples were obtained from the patient and his family members. Seventeen coding exons and intron-exon boundaries of the NTRK1 gene were amplified with PCR and analyzed by direct sequencing.

RESULTSA novel mutation c.2086_2087insC (p.Arg696 fsx) was identified in exon 16 of the NTRK1 gene in the proband. This insertion has caused open reading frame shifting and a premature termination has occurred just one codon downstream. Truncation of 72 amino acids at the C terminus has wiped out part of the tyrosine kinase domain (TKD) of the protein. Both of the proband's parents and two grandmothers have carried the c.2086_2087insC (p.Arg696 fsx) mutation. No mutation was found in the NTRK1 gene of other siblings.

CONCLUSIONMutation analysis of the NTRK1 gene has been carried out in a Chinese family affected with CIPA, and a novel NTRK1 gene mutation was identified.

Base Sequence ; Child, Preschool ; DNA Mutational Analysis ; Exons ; genetics ; Hereditary Sensory and Autonomic Neuropathies ; genetics ; Humans ; Male ; Mutation ; Polymerase Chain Reaction ; Receptor, trkA ; genetics