A C-->G nucleotide transition in exon 4 of PTPRC (encoding protein-tyrosine
phosphatase receptor-type C, also known as CD45) was recently reported to
be genetically associated with the development of multiple sclerosis (MS)(1
). We performed an extensive evaluation of this polymorphism using large fa
mily-based and case-control comparisons. Overall, we observed no evidence o
f genetic association between the PTPRC polymorphism and MS susceptibility
or disease course.