Miko et al. J Biomed & App Sci FUD (2024) 3:2
Keywords: Cytogenetic Analysis, Down Syndrome, Karyotyping, Maternal Age, Trisomy 21
2025-05-09 DOI: JOBASFUD_2024_3_2_003
Background Down syndrome (DS) is a prevalent genetic disorder caused by chromosomal abnormalities, primarily free trisomy 21. While advanced maternal age is a well-documented risk factor for DS, data specific to Northwestern Nigeria is limited. This study aimed to investigate the association between maternal age and the various cytogenetic types of DS in Kano State, Nigeria. Materials and Methods: The study involved purposively selecting and karyotyping 16 DS cases identified through peripheral blood samples at the Centre for Genetic Studies, Maulana Abul Kalam Azad University, Kolkata, India. Maternal and paternal ages were recorded, and statistical analyses were performed using Pearson’s Chi-square test, independent samples, and receiver operating characteristic (ROC) curves to evaluate the significance of age as a risk factor. Results: The mean maternal age of mothers with DS was 35.66 ± 8.53 years, significantly higher than that of non-trisomic controls (31.28 ± 5.96 years; p = 0.002). All cases were identified as free trisomy 21, with no translocation or mosaic DS instances. The study found that maternal age was a significant risk factor (AUC=0.67, p=0.025), with a cut-off of 42 years indicating high risk. Paternal age did not show a significant correlation with DS risk. Conclusion: The findings confirm that advanced maternal age is a significant risk factor for free trisomy 21 in Kano State, reflecting global trends. However, the absence of other cytogenetic types suggests a need for broader research across Nigeria. Enhanced prenatal screening and genetic counselling are recommended for older mothers to manage DS risk better and inform preventive strategies.