Investigating AXIN1 gene polymorphisms in Turkish children with cryptorchidism: A pilot study.

Introduction: Cryptorchidism is one of the most common congenital anomalies in male children, occurring in 2-5% of full-term male infants. Both genetic and environmental factors are observed to play a role in its etiology. A study conducted in Japan identified the AXIN1 gene as being associated with cryptorchidism.

Objective: We aimed to conduct a pilot study on AXIN1 gene polymorphism in Turkish children with cryptorchidism, and whether AXIN1 gene polymorphism is a risk factor for cryptorchidism.

Study Design: Between January 2023 and December 2023, we have planned a prospective controlled study including 84 boys operated for cryptorchidism as study group, and 96 boys operated for circumcision as control group. The remaining blood samples of preoperative laboratory tests in ethylenediamine tetraacetic acid (EDTA) tubes were kept at -20 C freezer for genomic studies. Patient demographics, physical examination and operative findings were recorded, study patients were grouped according to testis localization. After collecting all samples, genomic DNA isolation procedure was done, and analysis of the 3 polymorphisms (rs12921862, rs1805105 and rs370681) of AXIN1 gene was performed using conventional Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) method. Genotype and allele frequencies of each group was analyzed and compared.

Results: The most common location of cryptorchid testis was proximal inguinal (53%), followed by distal inguinal (25.3%), bilateral (13.3%), and intra-abdominal (8.4%). Regarding the 3 polymorphisms of AXIN1 gene, there was no significant difference between study and control groups, in terms of genotype and allele frequencies (P > 0.05). Eight haplotype blocks were estimated for 3 polymorphisms of AXIN1. However, no significant difference was observed between study and control groups regarding haplotype distributions (P > 0.05). In addition, the comparison of the localization of testis with AXIN1 gene polymorphism did not show any significant difference among cryptorchid testis groups (P > 0.05).

Discussion: The AXIN1 gene is located on chromosome 16p and its polymorphisms have been associated with various diseases. In a Chinese study, the rs370681 polymorphism was found to be associated with cryptorchidism. However, our results showed no association between the AXIN1 gene haplotypes for the studied polymorphisms and cryptorchidism.

Conclusion: In this study we have investigated the AXIN1 gene polymorphism in Turkish children with cryptorchidism as a pilot study. Although we could not identify any difference as compared to control group, further research is necessary to uncover the underlying molecular mechanisms contributing to the development of cryptorchidism.