Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe a child with thrombocytopenia-absent radius (TAR) syndrome in whom a refractory Langerhans cell histiocytosis (LCH) developed at 9 years. Recently, it has been demonstrated, in a large cohort of patients with TAR syndrome, that microdeletion on chromosome 1q21.1 is the characteristic genetic alteration. This genetic alteration was found in the affected son and in maternal lineage. Our data confirm the role played by the 1q21.1 microdeletion in the pathogenesis of TAR syndrome proposing a panel of polymorphic markers for a rapid and low-cost screening of 1q21.1 microdeletion. We do not know if the occurrence of two rare diseases as of TAR syndrome and LCH could be considered a chance association; at our knowledge, a genetic link does not seem to be present between the diseases. Descriptions of additional cases of LCH in patients with TAR syndrome are necessary before a cause and effect relationship can be proven.
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PMID:Langerhans cell histiocytosis in a pediatric patient with thrombocytopenia-absent radius syndrome and 1q21.1 deletion: case report and proposal of a rapid molecular diagnosis of 1q21.1 deletion. 2142 12

Thrombocytopenia-absent-radius (TAR) syndrome is a rare condition characterized by thrombocytopenia and bilateral absence of the radii with presence of both thumbs. The phenotype has a variable expression. A 200 kb minimal deletion at 1q21.1 is present in all patients. However, the microdeletion, ranging up to 1100 kb in length, is not sufficient to cause the disease. Indeed it is present in 75-80% of unaffected parents. It is assumed that the phenotype develops only in the presence of one or more additional, as-yet-unknown, deletion modifiers (mTARs). We report here on a child affected by TAR syndrome associated with Langerhans cell histiocytosis. Unexpectedly, he showed a 2.029 kb deletion at 1q21.1, almost twice that of the unaffected mother (957 kb). Interestingly, the mother-to-son increased size of the deleted region was already observed in two cases of constitutional diseases, although both resulting as chromosomal terminal deletions. Noteworthy, qPCR experiments, never before performed for patients with TAR syndrome, disclosed that the proband had a statistically significant downregulation of the majority of the genes mapping inside the part of the deletion shared with the mother. The mother, on the contrary, did not show the same downregulation. In summary, the present report adds new insights on the pathogenesis of TAR syndrome, that may represent fruitful directions for future research.
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PMID:Thrombocytopenia-absent-radius syndrome in a child showing a larger 1q21.1 deletion than the one in his healthy mother, and a significant downregulation of the commonly deleted genes. 2220 59

We describe a patient with thrombocytopenia-absent radius (TAR) syndrome, multisystemic Langerhans cell histiocytosis and multiple reticulohistiocytomas. A mutational study by massive sequencing identified the Val600Glu (V600E) BRAF mutation in the Langerhans cell histiocytosis lesions, but no molecular alterations were found in the reticulohistiocytoma lesions. The concomitant presence in the same patient of more than one type of histiocytosis from two different groups recognized in the most recent Histiocyte Society classification is an extremely rare event. Our case is the first reported case of multisystemic Langerhans cell histiocytosis and multiple reticulohistiocytomas in a patient with TAR syndrome.
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PMID:Langerhans cell histiocytosis and multiple reticulohistiocytomas in a patient with TAR syndrome: An association not previously described. 3100