One allele in a snp?

[cookiemonster]

If I understand snps correctly, they should have two alleles ... as in T/T or A/G, etc.

What does it mean on my 23andme report if it shows only one allele for a particular snp? (just one T on MAOA, for example)

 

[Valentijn]

What does it mean on my 23andme report if it shows only one allele for a particular snp? (just one T on MAOA, for example)

It means you're a guy

MAOA is on the X chromosome, so you only get one copy.

 

[cookiemonster]

Oh OK, thank you Valentijn ... I didn't know that, I thought I it meant I was just extremely defective!