But those are three of the most significant of the possible BRCA mutations, no?
Micro-array analysis (as opposed to the Exome sequencing they are starting to offer, which may be useful for BRCA diagnosis) focusses on frequently occurring single nucleotide polymorphisms (substitution of one base for another). The majority of these are benign.
By looking at lots of commonly occurring variants it is hoped that they can map regions of the genome that may harbour other mutations that may actually have an effect.
Baynes et al., 2007 [1] showed that none of the commonly occurring SNP's in BRCA (> 1-5% of the population) have a significant risk in cancer.
There is currently a case before the Supreme Court trying to invalidate Myriad's patents, as well as all patents on human DNA.
The issue, however, is that Myriad's value is no longer in their patents, but in the data they collected over the past 20 years.
Myriad charges ~$3k for their tests, while a full sequence of your entire genome is only ~$5k, and will tell you the same genetic data. But Myriad has been able to correlate much more of your DNA and the BRCA regions with cancer risk, and that data is not public.
23andMe is definitely not a substitute.
For anyone interested in the patents and the current Supreme Court case, check out: http://www.genomicslawreport.com/index.php/2013/05/01/some-t...
That's a great blog on genomics and the law, and there are other interesting blog posts on Myriad if you look through their archive.