1 Brown/1 Blue eye

[Sean Eddy]

In article <49bd5e$68e at decaxp.harvard.edu> robison at nucleus.harvard.edu (Keith Robison) writes:
  >: I have a student who has one beautiful brown eye, and one beautiful blue
  >: eye.  Do any of you know the genetic/molecular mechanism behind this
  >: phenomenon?  Any idea how common it is?  I would appreciate any
  >: information, or references.
  >
  >Presumably your student is exhibiting genetic mosaicism...
  >One possiblity is that the
  >brown allele was inactivated by a somatic mutation; the other is
  >loss of the brown allele via somatic recombination (I haven't 
  >a clue as to which has a higher frequency).

Another possibility is the early embryonic fusion of dizygotic
(fraternal) twins, I think.

--
- Sean Eddy
- Dept. of Genetics, Washington University School of Medicine
- eddy at genetics.wustl.edu