Intracytoplasmic inclusions composed of alpha-synuclein (alpha-syn) are characteristic of neurodegenerative Lewy body disorders. Using novel monoclonal antibodies raised against altered alpha-syn, we uncovered an unprecedented and extensive burden of alpha-syn pathology in the striatum of Lewy body disorders. The highest density of striatal pathology was observed in patients with a combination of Alzheimer's disease and dementia with Lewy bodies or pure dementia with Lewy bodies, and these alpha-syn aggregates may contribute to the parkinsonism seen in these disorders.

Previous genetic analysis of the familial Parkinson's disease Contursi kindred led to the identification of an Ala53Thr pathogenic mutation in the alpha-synuclein gene. We have re-examined one of the original brains from this kindred using new immunohistochemical reagents, thioflavin S staining and immunoelectron microscopy. Surprisingly, we uncovered a dense burden of alpha-synuclein neuritic pathology and rare Lewy bodies. Immunoelectron microscopy demonstrated fibrillar alpha-synuclein-immunoreactive aggregates. Unexpected tau neuritic and less frequent perikaryal inclusions were also observed. Some inclusions were comprised of both proteins with almost complete spatial disparity. We suggest that it is important to recognize that the neurodegenerative process caused by the Ala53Thr mutation in alpha-synuclein is not identical to that seen in typical idiopathic Parkinson's disease brains.

IntroductionThe FMS-related tyrosine kinase-3 (FLT3) is a receptor tyrosine kinase expressed in early hematopoietic progenitors that plays an important role in hematopoietic development. 1,2 Multiple studies have shown that activating mutations of FLT3 are common in blasts from patients diagnosed with acute myelogenous leukemia (AML) but are rarely found in adult patients with acute lymphoblastic leukemia (ALL). [2][3][4] We have recently shown that FLT3 is consistently highly expressed in MLL rearranged acute lymphoblastic leukemias (MLLs). 5 This prompted analysis for FLT3 mutations in MLL, where we found approximately 15% contain activating mutations in the receptor activation loop. 6 A large gene expression analysis of childhood ALL samples has shown that high-level FLT3 expression is also found in ALL samples containing more than 50 chromosomes (hyperdiploid ALL). 7 Here we show that activating FLT3 mutations are found in diagnostic specimens from 6 of 25 patients with hyperdiploid ALL, but only 1 of 29 patients with TEL/AML1-rearranged ALL. Also, 3 of 16 patients with leukemia who would ultimately have a relapse harbored FLT3 mutations. Most of the mutations are previously described activation loop mutations, but 4 are new mutations consisting of either small deletions or insertions in the juxtamembrane region of the receptor. These data suggest that patients with hyperdiploid or relapsed ALL should be considered possible candidates for therapy with recently described small-molecule FLT3 inhibitors. [8][9][10][11] Study design Patient samplesLeukemia samples were obtained from either bone marrow or peripheral blood at diagnosis from patients with ALL. The peripheral blood samples all had more than 10% blasts at diagnosis. Patients were treated according to Dana Farber Cancer Institute protocols 91-001, 95-001, and 00-001. Informed consent was obtained from all patients after approval of the Institutional Review Board. Standard cytogenetic analysis was performed on all samples. TEL-AML1 translocations were determined by florescence in situ hybridization (FISH) or polymerase chain reaction (PCR) as previously described. 12 Mutation detectiongDNA was extracted from leukemia samples with Trizol (Invitrogen, Carlsbad, CA). Mutations in the juxtamembrane domain were identified by amplifying a region spanning exons 14 and 15 with primers 14F (TGTA-AAACGACGGCCAGTCAATTTAGGTATGAAAGCC) and 15R (GAG-GAAACAGCTATGACCCTTTCAGCATTTTGACGGCAACC). The upstream primer in this reaction was fluorescently labeled (6-FAM) to allow sizing of all products when electrophoresed on a sequencing apparatus (Model 377, Applied Biosystems, Foster City, CA). The area under the curve of a variant product was divided by the total area under all curves to approximate the percentage of variant alleles in a sample. When variant products were determined to constitute more than 30% of the signal, the sample was directly sequenced following the initial PCR. Samples with no detectable length mutations were also directly sequenced. For a sample with ...