1 doctor weighed in:

My brother and I both tested positive for colorblindness, but neither of our parents are?

1 doctor weighed in
Dr. Gurmukh Singh
Pathology

In brief: X-linked

Color blindness is x-linked and you got it from your mother. I take it that you are a boy/man.
Your mother is not affected because she has two x-chromosomes and only one is defective. You and your brother happened to have inherited the defective x-chromosome from your mother. Since men have only one x-chromosome inheriting a defective one manifests itself as color blindness.

In brief: X-linked

Color blindness is x-linked and you got it from your mother. I take it that you are a boy/man.
Your mother is not affected because she has two x-chromosomes and only one is defective. You and your brother happened to have inherited the defective x-chromosome from your mother. Since men have only one x-chromosome inheriting a defective one manifests itself as color blindness.
Dr. Gurmukh Singh
Dr. Gurmukh Singh
Thank
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