obsolete blood group, vel system https://github.com/monarch-initiative/mondo/issues/4521 https://www.malacards.org/card/blood_group_vel_system true VEL MONDO:0044282 OBSOLETE. The Vel blood group system is defined by the presence of the Vel antigen on red blood cells. Vel is a high frequency antigen that shows variable strength, ranging from strong to weak. The rare Vel-negative blood type is inherited as an autosomal recessive trait and is typically unveiled when Vel-negative individuals develop anti-Vel antibodies after transfusion or pregnancy; Vel alloantibodies are never 'naturally occurring.' Individuals with anti-Vel antibodies may develop severe acute hemolytic transfusion reactions when transfused with Vel-positive blood. Individuals negative for the Vel antigen are rare and are required for the safe transfusion of patients with antibodies to Vel (summary by {3:Daniels, 2002}; {5:Storry et al., 2013}; {2:Cvejic et al., 2013}; {1:Ballif et al., 2013}). OMIM:615264 Obsoleted as it represents a trait or is a legacy entry blood group, Vel system