He was a Bangladesh Awami League Advisory Council member and former lawmaker.
He was awarded Ekushey Padak in 2015 by the government of Bangladesh for his contribution to education.
He obtained his FCPS degree in internal medicine from the Bangladesh College of Physicians and Surgeons in 1987.
[citation needed] Mannan was an elected Awami League member of parliament (MP) from the Kishoreganj-2 (Katiadi-Pakundia) constituency in 2001 and 2008.
[3] He was the founding head of the Department of Neurology of Institute of Post Graduation and Medical Research (now named BSMMU).