One of the colors of mink is Aleutian (aa)-a specific gun-metal gray 
pigmentation of the fur-commonly used in combination with other color loci to 
generate popular colors such as Violet (aammpp) and Sapphire (aapp). The 
Aleutian color allele is a manifestation of mink Chédiak-Higashi syndrome (CHS), 
which has been described in humans and several other species. As with forms of 
CHS in other species, we report that the mink CHS is linked to the lysosomal 
trafficking regulator ( LYST ) gene. Furthermore, we have identified a base 
deletion (c.9468delC) in exon 40 of LYST, which causes a frameshift and 
virtually terminates the LYST product prematurely (p.Leu3156Phefs*37). We 
investigated the blood parameters of three wild-type mink and three CHS mink. No 
difference in the platelet number between the two groups was observed, but an 
accumulation of platelets between the groups appears different when collagen is 
used as a coagulant. Microscopic analysis of peripheral blood indicates giant 
inclusions in the neutrophils of the Aleutian mink types. Molecular findings at 
the LYST locus enable the development of genetic tests for analyzing the color 
selection in American mink.