Identification of Mutation in Exon2 of the NKX2.5 Gene in Bangladeshi Pediatric Patients with Congenital Hypothyroidism

Context and rationale: Congenital hypothyroidism is a prevalent endocrine disease that may occur due to the alteration in the sequence of nucleotides of the NKX2.5 gene. Though congenital hypothyroidism is quite common among the Bangladeshi pediatric population, there are few studies on the genetic basis of this disease. Objective: This study aimed to identify any mutation in the exon2 of the NKX2.5 gene in Bangladeshi pediatric patients with congenital hypothyroidism. Methods: Forty (40) Bangladeshi pediatric patients with congenital hypothyroidism were recruited, the sociodemographic data were collected and analyzed, DNA was isolated, quantity and quality of DNA were checked, polymerase chain reaction (PCR) was done, the amplicons were visually validated by gel electrophoresis and cycle sequencing was done by Sanger sequencing. The raw chromatogram data were analyzed and compared with the NCBI database by BLAST (Basic Local Alignment Search Tool) search. Results: Sanger sequencing revealed two types of alteration in the nucleotide sequence. Nine patients showed substitutions (c.1051G>T) and eight patients showed deletions (c.1143 delT-), and both substitution and deletion were present in four patients. This substitution and deletion occurred in the Sequence Tagged Site (STS) of the exon2 of the NKX2.5 gene and these are new variants and not reported in NCBI database. Conclusion: In the present study, two types of variants were identified. So, further study to find out mutational status among Bangladeshi children might be helpful in enriching the database of mutational spectra of pediatric patients with congenital hypothyroidism.