Never. Although, genes for ABO and Rh blood groups are present on the surface of RBCs but ABO and Rh blood group systems are different. Rh positive is always dominant to Rh negative gene irrespective of ABO blood groups. Hence, Rh positive blood group always express itself.
ABO and Rh
A. Nickle has written: 'ABO and Rh blood groups'
Testing for Rh antigens and antibodies is done to determine the presence of the Rh factor in the blood, which is a separate system from the ABO blood group system. Rh testing is important for determining compatibility in blood transfusions and during pregnancy. ABO testing, on the other hand, evaluates the presence of A, B, AB, or O antigens on red blood cells to determine blood type.
To type blood according to abo, the lab detects the proteins of the cells to determine whether blood is a b or o. To further type blood into rh- and rh positive, the lab checks antibodies to specific proteins.
When we classify blood cells by their antigens we can classify them according to the ABO blood groups or the Rh blood groups. The Rh will either be + or -. They are usually used in conjunction so you might be A pos or O neg.
Type A+ blood type denotes your blood group. Under the ABO system there are four blood groups which include A, B, AB, and O. Furthermore these can be categorized as rh positive and rh negative.
It depends what blood group or system you are interested in. The major blood groups are the ABO and Rh system. In addition to these, there are approximately 30 other blood groups/systems of importance in immunohematology.
ABO is not correlated to Rh+/Rh-. With the conditions stated in the question, the mother could be type A, B or O, and is certainly type RH+. So, she can be A+, B+ or O+.
ABO
No, there is no blood group designated as "g" in the ABO or Rh blood group systems. The major blood groups are A, B, AB, and O, along with the Rh factor, which can be positive or negative. Other blood group systems exist, but "g" is not recognized as one of them.
Knowing your blood type (Rh positive or negative) does not determine your genotype with 100% certainty. Specific genotyping tests are needed to determine the exact genetic makeup of the Rh factor (e.g., whether you are RhD positive or negative) in addition to your ABO blood type.