Whats the M in chromosome 3?

[aleferna]

anybody knows whats with the letter M in position
chr3:60830521-60830580 ?

Who do you call if there is an error in the official human genome?


ftp://ftp.ncbi.nlm.nih.gov/genbank/g...STA/chr3.fa.gz

[swbarnes2]

Generally, 'M' means that the letter in question is either an A or a C. So it's probably not a typo, maybe they couldn't determine which letter it was from their data.

[Jon_Keats]

Seems to depend on the source of the genome files. NCBI, seems to still have them, UCSC has always convered to Ns, Ensembl had them for a bit (in 1kg ref files for instance) but disappeared in later versions.

See this previous thread

http://seqanswers.com/forums/showthread.php?t=6691