HNA is an autosomal dominant recurrent focal neuropathy involving
the brachial plexus. The
etiology of HNA is unknown but the genetic defect most likely affects a
non-neuronal tissue. We
previously described linkage to chromosome 17q24–q25 in two HNA-families.
Here we report the
mutation analysis of two candidate genes: a cDNA encoding a putative sialyltransferase
and the
SFRS2 splicing factor including the c-myb ET-locus which
is encoded on the opposite strand of the
SFRS2 gene. The complete protein coding regions of both genes
were studied by direct DNA
sequencing. We did not find a disease associated mutation indicating that
these genes are most likely
not involved in the pathogenesis of HNA. However, we identified and characterized
a rare AvaII
polymorphism in the SFRS2 gene and detected a sequencing error,
leading to an amino acid change
(Val11Leu) in the published sequence of the putative sialyltransferase.