لخّصلي

Background. Male infertility refers to the inability to achieve clinical pregnancy after 12
months of unprotected intercourse. Various factors contribute to male infertility, with
genetic factors accounting for 50% of cases. Asthenozoospermia, a condition characterized
by low sperm motility, represents 13% of male infertility cases. This condition is linked to
reduced ATP synthesis in the mitochondria. The mitochondrial genome comprises 13 genes,
one of these genes is the ND3 gene, a part of complex 1 in mitochondria, which plays a
crucial role in the ATP synthesis process.
Objectives. The study aims to investigate the mitochondrial ND3 gene in
asthenozoospermic males in Jordan, with a focus on scanning for potential genetic variations
or abnormalities that may contribute to this specific form of male infertility.
Method. The study involved 188 men, comprising 117 with asthenozoospermia and 71 with
normozoospermia, collected from the Royal Jordanian Medical Services in vitro fertilization
(IVF) units. Extracted Mitochondrial DNA (mtDNA) from semen samples from normal as
well as asthenozoospermic using a commercial kit according to the manufacturer's
instructions. polymerase chain reaction (PCR) was used to amplify the MT-ND3 gene.
Genetic variants were identified through direct Sanger's sequencing. The chi-square test and
Fisher's exact test were employed to compare genotypes and allele frequencies between the
asthenozoospermic and normozoospermic groups.
Results. A total of seventeen single nucleotide polymorphisms (SNPs) in the MT-ND3 gene;
were detected in the asthenozoospermic and normozoospermic groups at different
nucleotide positions, one of this SNPs found in the normozoospermic group is novel SNP;
while the other SNPs were previously reported in the National Center for Biotechnology
Information (NCBI) and database Human Mitochondrial Database(mtDB). Six variants were
found through which the amino acid is changed in translation) missense variants( ,
distributed as follows: The SNPs found two missense variants that change the amino acids
in asthenozoospermic; rs41487950 T>C (Ile9Thr) and rs1603222800 G>A (Ala103Thr). InXII
addition to three missense variants in normozoospermic; rs202131419 G>A (Gly29Ser),
rs193302928 T>C (Val88Ala), and rs1603222776 T>C (Met89Thr), also found one
missense variants in asthenozoospermic and normozoospermic; rs2853826 A>G
(Thr114Ser). Eleven variants were found whose translation does not cause a change in the
amino acid )synonymous variants(, distributed as follows: two synonymous variants in
asthenozoospermic; rs1603222690 A>G (Leu24) and rs163222794 A>G (Leu98). In
addition to three synonymous variants in normozoospermic; rs2068720641 C>A (Val49),
rs1603222757 C>T (Leu75) and rs1603222805 A>G (Trp106). Finally found six
synonymous variants in asthenozoospermic and normozoospermic; rs3899188 T>C (Ile19),
rs878969753 C>T (Asn28), rs1556423786 A>G (Met53), rs193302927 T>C (Ile60),
rs1556423796 A>G (Trp77), and rs28358278 C>T (Thr114).
Conclusion. One novel variant and sixteen known variants were found in the MT-ND3 gene
in normozoospermic males and asthenozoospermic there is no association between
asthenozoospermia and these variants. However, further studies are recommended to clarify
the role of these alterations in the development of male infertility in other populations.