Question regarding the MAF Calculation Section

[Habush]

Hi,

First of all, thank you for creating this amazing resources for learning about GWAS pipeline!

I'm following along the tutorial and I stumbled about this formula on the 04_Data_QC section. In the the textbox that explains how MAF is calculated it is stated, for a in a population of N samples (2N alleles), $N = N_{AA} + 2 N_{AB} + N_{BB}$. I'm wondering why the number of heterozygous samples is multiplied by 2. I would have thought the formula would simply be: $N = N_{AA} + N_{AB} + N_{BB}$. Maybe I'm misunderstanding something as I'm new to the genomics field.

[Cloufield]

Hi,
Thank you very much for the feedback!
Indeed, it should be N_AA + N_AB + N_BB as you pointed out.
The Ns of samples and alleles were mixed up for that part.
The error has been fixed now.