Publications by authors named "Jannie Janssen"

Various groups of neurological disorders, including movement disorders and neuromuscular diseases, are clinically and genetically heterogeneous. Diagnostic panel-based exome sequencing is a routine test for these disorders. Despite the success rates of exome sequencing, it results in the detection of causative sequence variants in 'only' 25-30% of cases.

View Article and Find Full Text PDF

Background: In patients with myeloproliferative neoplasia (MPN) the development of fibrosis and increased vessel density correlate with poor prognosis. The JAK2(V617F) mutation constitutively activates JAK2, which phosphorylates signal transducer activator of transcription (STAT), up-regulating vascular endothelial growth factor (VEGF), which might be responsible for angiogenesis in MPN. Galectins are involved in the development of fibrosis and angiogenesis and might also be involved in activation of the JAK/STAT pathway in MPN.

View Article and Find Full Text PDF

A partial deletion of chromosome band 2p25.3 (2pter) is a rarely described cytogenetic aberration in patients with intellectual disability (ID). Using microarrays we identified deletions of 2p25.

View Article and Find Full Text PDF

A 55-year-old man sought care for aggressive acute lymphoblastic leukemia (ALL), which developed 8 years after he had received chemotherapeutic treatment for nephrotic syndrome. The sole cytogenetic abnormality observed in bone marrow-derived metaphases was a t(4;11)(q21;q23), which is a frequently occurring translocation in ALL. However, subsequent reverse transcriptase-polymerase chain reaction for the expected mixed lineage leukemia [trithorax homolog, Drosophila] (MLL)-AFF1 fusion transcript was negative.

View Article and Find Full Text PDF

Genotypic and phenotypic data are presented on three adult siblings with mild to moderate mental retardation and mild dysmorphic features. All three siblings showed a chromosome 20 gain at the q-telomere and loss at the p-telomere in routine subtelomeric MLPA screening. Analysis of GTG-banded chromosomes did not detect any abnormalities, but subtelomeric fluorescent in situ hybridization (FISH) confirmed cryptic partial monosomy of chromosome region 20p13 --> 20pter and cryptic partial trisomy of chromosome region 20q13.

View Article and Find Full Text PDF

Genetic abnormalities leading to infant leukemias already occur during fetal development and often involve rearrangements of the mixed-lineage leukemia (MLL) gene. These rearrangements resemble the aberrations observed in therapy-related leukemias following treatment with topoisomerase II (topoII)-inhibiting agents such as etoposide. Since flavonoids are potent topoII inhibitors, we examined the role of three widely consumed dietary flavonoids (quercetin, genistein and kaempferol) on the development of MLL rearrangements in primary human CD34(+) cells.

View Article and Find Full Text PDF

The degenerate subcutaneous eye of the blind mole rat belonging to the Spalax ehrenbergi superspecies has been shown to contain a long wavelength sensitive (LWS) cone pigment. Baculovirus expression of this LWS pigment and subsequent IMAC purification yields a photosensitive protein, that according to absorbance maximum (530 +/- 2 nm), kinetics of late phototransitions, and transducin activation, has all characteristics of a functional green cone pigment. The absorbance spectrum of the Spalax pigment is strongly red-shifted relative to the very homologous mouse, rabbit and rat green cone pigments (508-510 nm).

View Article and Find Full Text PDF