Epidemiological Profile of Trisomy 21 in Senegal

Author(s): Yaay Joor Koddu Biigé DIENG, Seydi Abdou BA, Djénéba Fafa CISSE, Aminata MBAYE, Ndèye Fatou SOW, Guillaye DIAGNE, Awa KANE, Madjiguène KANE, Grace Neema SIKULI, Papa Moctar FAYE, Amadou Lamine FALL, Ousmane NDIAYE

Introduction: Trisomy 21 (T21) is the most common genetic cause of learning disabilities and congenital malformations in humans. The genetic background is well established and maternal age is the main risk factor implicated. The aim of this study was to describe the epidemiological profile of T21 in the Senegalese population.

Patients and method: This was a 7-year retrospective observational study, from November 2016 to October 2023. We considered all cases of T21 in the cohort of the genetic consultation at the Albert Royer Children's Hospital. The data collected were analysed using SPSS 21.

Results: We collected 218 cases of T21 among the 378 patients seen at the consultation. According to the inclusion criteria, 205 cases of patients with T21 were selected. The sex ratio was 0.99. Consanguinity was found in 17.1% of patients and T21 in 2.9%. At least one spontaneous abortion was found in 27.8% of the mothers. The median age of the mothers at conception was 37 years. The 35-39 age group was the most represented (35.6%). A deep organ malformation was found in 70.9% of cases, dominated by cardiopathies (60.9%), the most frequent of which were: atrioventricular canal (44%), atrial septal defect (21.1%), persistent ductus arteriosus (18.3%) and interventricular septal defect (15.6%).

Conclusion: Maternal age, the main risk factor identified for T21, seems to present a different profile, notably younger in our series.