HealthCareMagic is now Ask A Doctor - 24x7 | https://www.askadoctor24x7.com

question-icon

What Determines A Child's Blood Group?

default
Posted on Fri, 4 Nov 2016
Question: My Dad is O+ and my Mum is A2B+ but my blood type is B-. How is this possible?
doctor
Answered by Dr. Michelle Gibson James (34 minutes later)
Brief Answer:
an AB and O parent produce a child that is either A or B

Detailed Answer:
HI, thanks for using healthcare magic

First looking at the positive (+, rhesus +) and negative (-, rhesus negative): (1) two parents with positive can have a child with a negative.
Positive or negative is determined by the presence of two RH settings/genotypes in the body.

Meaning: if both genotypes/setting for RH are negative (- -) then they would be rhesus negative,
If both settings/genotypes for rh are positive (++), then they would be rhesus positive
If one setting is positive and one is negative (+ -) , then they would Still be considered or found to be rhesus positive

This is important, it means that though both of your parents could have the setting (+ -), when this is combined , they can have a child that gets the negative from both of them- a rhesus negative child

As for the blood type, an AB parent and O parent would have a child that is either blood type A or B, so your blood type of B is completely normal.

I hope this helps, feel free to ask any other questions
Note: Do you have more questions on diagnosis or treatment of blood disorders? Ask An Expert/ Specialist Now

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
Answered by
Dr.
Dr. Michelle Gibson James

General & Family Physician

Practicing since :2001

Answered : 16808 Questions

premium_optimized

The User accepted the expert's answer

Share on

Get personalised answers from verified doctor in minutes across 80+ specialties

159 Doctors Online

By proceeding, I accept the Terms and Conditions

HCM Blog Instant Access to Doctors
HCM Blog Questions Answered
HCM Blog Satisfaction
What Determines A Child's Blood Group?

Brief Answer: an AB and O parent produce a child that is either A or B Detailed Answer: HI, thanks for using healthcare magic First looking at the positive (+, rhesus +) and negative (-, rhesus negative): (1) two parents with positive can have a child with a negative. Positive or negative is determined by the presence of two RH settings/genotypes in the body. Meaning: if both genotypes/setting for RH are negative (- -) then they would be rhesus negative, If both settings/genotypes for rh are positive (++), then they would be rhesus positive If one setting is positive and one is negative (+ -) , then they would Still be considered or found to be rhesus positive This is important, it means that though both of your parents could have the setting (+ -), when this is combined , they can have a child that gets the negative from both of them- a rhesus negative child As for the blood type, an AB parent and O parent would have a child that is either blood type A or B, so your blood type of B is completely normal. I hope this helps, feel free to ask any other questions