16 research outputs found
A distinct clinical phenotype in a German kindred with motor neuron disease carrying a CHCHD10 mutation.
peer reviewe
Primary CNS lymphoma and HLA class I and II alleles in a German cohort of immunocompetent patients
Human leukocyte antigens (HLA) are involved in the regulation of immune response to infection and in malignant transformation. Several HLA alleles are associated with immunological or malignant diseases. The aim of the present study was to evaluate a potential association of HLA class I and II alleles with primary central nervous system lymphoma (PCNSL) in immunocompetent patients. We therefore analyzed particular HLA-A, HLA-B and HLA-DRB1 alleles in 82 PCNSL patients and compared the data to those in 327 population controls. No significant difference between these two groups was found using Pearson's chi(2) test. These data do not support the hypothesis that HLA alleles play a major role in the pathogenesis of PCNSL
Genetic variants of folate and methionine metabolism and PCNSL incidence in a German patient population
Functional genetic polymorphisms involved in folate and methionine metabolism play an important role in both DNA synthesis and methylation, and affect the risk of various malignancies including lymphoproliferative disorders such as systemic non-Hodgkin's lymphoma. In a retrospective analysis of 185 immunocompetent patients with primary central nervous system lymphoma (PCNSL) and 212 population controls we therefore investigated eight genetic polymorphisms affecting methionine metabolism for potential association with the development of PCNSL. We observed underrepresentation of the G-allele of the methyltetrahydrofolate homocysteine S-methyltransferase (MTR) c.2756A > G (D919G) missense polymorphism among PCNSL patients (P = 0.045; odds ratio (OR) = 0.65; 0.43-0.99). Furthermore, for the methylenetetrahydrofolate reductase (MTHFR) c.1298A > C (E429A) polymorphism the mutated C-allele was found more frequently among PCNSL patients than among population controls (P = 0.026; OR = 1.57; 1.05-2.34). There were no associations of the other polymorphisms investigated (MTHFR c.677C > T, transcobalamin 2 (Tc2) c.776C > G, cystathionin beta-synthase (CBS) c.844_855ins68, reduced folate carrier-1 (RFC-1) c.80G > A, thymidylate synthase (TYMS) 28-bp repeat, and dihydrofolate reductase (DHFR) c.594 + 59del19 bp) and the presence of PCNSL. This analysis is the largest to date to evaluate associations between genetic variants of folate and methionine metabolism and PCNSL. Our results suggest the hypothesis that folate and methionine metabolism is relevant to susceptibility to PCNSL
Primary CNS lymphoma in the elderly: temozolomide therapy and MGMT status
This retrospective series explores temozolomide monotherapy in elderly patients with primary CNS lymphoma (PCNSL) and severe comorbidities. In 17 patients (62-90 years old), the complete response rate was 47%, median progression-free survival was 5 months, and median overall survival was 21 months. Five of 17 patients (29.4%) had prolonged responses for at least 12 months and survived for more than 24 months. Three of these patients had a methylated O(6)-methylguanine-DNA methyltransferase (MGMT) promoter, while the MGMT status was not assessable in the remaining two patients. Temozolomide monotherapy appears to be effective in a subgroup of elderly PCNSL patients and deserves further evaluation
High-dose methotrexate with or without whole brain radiotherapy for primary CNS lymphoma (G-PCNSL-SG-1): a phase 3, randomised, non-inferiority trial
BACKGROUND: High-dose methotrexate is the standard of care for patients with newly diagnosed primary CNS lymphoma. The role of whole brain radiotherapy is controversial because delayed neurotoxicity limits its acceptance as a standard of care. We aimed to investigate whether first-line chemotherapy based on high-dose methotrexate was non-inferior to the same chemotherapy regimen followed by whole brain radiotherapy for overall survival.
METHODS: Immunocompetent patients with newly diagnosed primary CNS lymphoma were enrolled from 75 centres and treated between May, 2000, and May, 2009. Patients were allocated by computer-generated block randomisation to receive first-line chemotherapy based on high-dose methotrexate with or without subsequent whole brain radiotherapy, with stratification by age (<60 vs ≥60 years) and institution (Berlin vs Tübingen vs all other sites). The biostatistics centre assigned patients to treatment groups and informed local centres by fax; physicians and patients were not masked to treatment group after assignment. Patients enrolled between May, 2000, and August, 2006, received high-dose methotrexate (4 g/m(2)) on day 1 of six 14-day cycles; thereafter, patients received high-dose methotrexate plus ifosfamide (1·5 g/m(2)) on days 3-5 of six 14-day cycles. In those assigned to receive first-line chemotherapy followed by radiotherapy, whole brain radiotherapy was given to a total dose of 45 Gy, in 30 fractions of 1·5 Gy given daily on weekdays. Patients allocated to first-line chemotherapy without whole brain radiotherapy who had not achieved complete response were given high-dose cytarabine. The primary endpoint was overall survival, and analysis was per protocol. Our hypothesis was that the omission of whole brain radiotherapy does not compromise overall survival, with a non-inferiority margin of 0·9. This trial is registered with ClinicalTrials.gov, number NCT00153530.
FINDINGS: 551 patients (median age 63 years, IQR 55-69) were enrolled and randomised, of whom 318 were treated per protocol. In the per-protocol population, median overall survival was 32·4 months (95% CI 25·8-39·0) in patients receiving whole brain radiotherapy (n=154), and 37·1 months (27·5-46·7) in those not receiving whole brain radiotherapy (n=164), hazard ratio 1·06 (95% CI 0·80-1·40; p=0·71). Thus our primary hypothesis was not proven. Median progression-free survival was 18·3 months (95% CI 11·6-25·0) in patients receiving whole brain radiotherapy, and 11·9 months (7·3-16·5; p=0·14) in those not receiving whole brain radiotherapy. Treatment-related neurotoxicity in patients with sustained complete response was more common in patients receiving whole brain radiotherapy (22/45, 49% by clinical assessment; 35/49, 71% by neuroradiology) than in those who did not (9/34, 26%; 16/35, 46%).
INTERPRETATION: No significant difference in overall survival was recorded when whole brain radiotherapy was omitted from first-line chemotherapy in patients with newly diagnosed primary CNS lymphoma, but our primary hypothesis was not proven. The progression-free survival benefit afforded by whole brain radiotherapy has to be weighed against the increased risk of neurotoxicity in long-term survivors.
Copyright © 2010 Elsevier Ltd. All rights reserved
Hypomorphic mutations in POLR3A are a frequent cause of sporadic and recessive spastic ataxia
Despite extensive efforts, half of patients with rare movement disorders such as hereditary spastic paraplegias and cerebellar ataxias remain genetically unexplained, implicating novel genes and unrecognized mutations in known genes. Non-coding DNA variants are suspected to account for a substantial part of undiscovered causes of rare diseases. Here we identified mutations located deep in introns of POLR3A to be a frequent cause of hereditary spastic paraplegia and cerebellar ataxia. First, whole-exome sequencing findings in a recessive spastic ataxia family turned our attention to intronic variants in POLR3A, a gene previously associated with hypomyelinating leukodystrophy type 7. Next, we screened a cohort of hereditary spastic paraplegia and cerebellar ataxia cases (n = 618) for mutations in POLR3A and identified compound heterozygous POLR3A mutations in similar to 3.1% of index cases. Interestingly, >80% of POLR3A mutation carriers presented the same deep-intronic mutation (c.1909 + 22G>A), which activates a cryptic splice site in a tissue and stage of development-specific manner and leads to a novel distinct and uniform phenotype. The phenotype is characterized by adolescent-onset progressive spastic ataxia with frequent occurrence of tremor, involvement of the central sensory tracts and dental problems (hypodontia, early onset of severe and aggressive periodontal disease). Instead of the typical hypomyelination magnetic resonance imaging pattern associated with classical POLR3A mutations, cases carrying c.1909 + 22G>A demonstrated hyperintensities along the superior cerebellar peduncles. These hyperintensities may represent the structural correlate to the cerebellar symptoms observed in these patients. The associated c.1909 + 22G>A variant was significantly enriched in 1139 cases with spastic ataxia-related phenotypes as compared to unrelated neurological and non-neurological phenotypes and healthy controls (P = 1.3 x 10(-4)). In this study we demonstrate that (i) autosomal-recessive mutations in POLR3A are a frequent cause of hereditary spastic ataxias, accounting for about 3% of hitherto genetically unclassified autosomal recessive and sporadic cases; and (ii) hypomyelination is frequently absent in POLR3A-related syndromes, especially when intronic mutations are present, and thus can no longer be considered as the unifying feature of POLR3A disease. Furthermore, our results demonstrate that substantial progress in revealing the causes of Mendelian diseases can be made by exploring the non-coding sequences of the human genome