Sperm parameters and mitochondrial DNA sequence variants among patients at a fertility clinic in Ghana

Abstract

Purpose The present study sought to investigate the common abnormalities and mtDNA mutations in the sperm of Ghanaian men attending the fertility Clinic at the Korle-Bu Teaching Hospital (KBTH). The study therefore provides a baseline data mtDNA mutations in a cross-section of Ghanaian men on referral to the fertility clinic at the KBTH. Materials and methods The semen of 55 men attending the fertility clinic were collected from the Urology and the Obstetrics and Gynaecology Departments of the KBTH. Demographic and clinical data were also collected using questionnaires. Semen analyses were performed and were followed by amplification and purification of mtDNA from total DNA extracted from the semen. Sequencing of the mtDNA amplicons was performed using the next generation sequencer (Illumina-MiSeq). Results Asthenozoospermia, oligospermia and oligoasthenoteratozoospermia were observed in 1.79%, 5.36% and 28.57%, respectively, of the study participants. There was no association between drinking and/or smoking and history of gonorrhea infection on sperm status/morphology. A total of 785 point mutations were detected in the non-coding control regions, rRNA genes, tRNA genes and the coding regions of the mtDNA samples from the participants. Amongst these mutations, 16 transition mutations were predominantly detected in the mtDNA samples. Missense mutations that were present in only specific sperm abnormalities were identified and they may contribute to infertility in the study population. Conclusion The present study has identified various abnormal sperm phenotypes that are prevalent in the study population and provided a baseline data on mtDNA mutations in the spermatozoa of the patients. A wide range of sperm abnormalities were detected in the study population with no association with life style or history of gonorrhea infection. The mtDNA point mutations detected in the selected genes that were analysed were mostly transition mutations. These transition mutations might be critical for the development of abnormal sperm phenotypes underlying male infertility in the Ghanaian population.