RET MUTATION SCREENING IN FAMILIAL CUTANEOUS LICHEN AMYLOIDOSIS AND IN SKIN AMYLOIDOSIS ASSOCIATED WITH MULTIPLE ENDOCRINE NEOPLASIA

In several families, multiple endocrine neoplasia type 2A (MEN 2A) has been found in association with cutaneous lichen amyloidosis. It has b een debated, however, whether the skin amyloidosis found in MEN 2A fam ilies, localized exclusively in the interscapular area, represents the same anomaly as that found in autosomal dominant familial cutaneous l ichen amyloidosis, which is more generalized. We screened two MEN 2A f amilies with associated skin amyloidosis for germline mutations in the RET gene responsible for the MEN 2A cancer syndrome, and found the sa me mutation characteristic of MEN 2A in both families, We also screene d probands from three pedigrees with familial cutaneous lichen amyloid osis for RET mutations. In none of the RET coding and flanking introni c sequences was a mutation detected. This most probably indicates that skin amyloidosis found in some MEN 2A families and familial cutaneous lichen amyloidosis are different conditions. Consequently, patients w ith apparent familial cutaneous lichen amyloidosis do not appear to be at risk for MEN 2A.