Human RTEL1 deficiency causes Hoyeraal- Hreidarsson syndrome with short telomeres and genome instability

International audienceHoyeraal-Hreidarsson syndrome (HHS), a severe variant of dyskeratosis congenita (DC), is characterized by early onset bone marrowfailure, immunodeficiency and developmental defects. Several factors involved in telomere length maintenance and/or protection are defective in HHS/DC, underlining the relationship between telomeredysfunctionandthese diseases.Bycombining whole-genomelinkage analysisandexomesequencing,we identified compound heterozygous RTEL1 (regulator of telomere elongation helicase 1) mutations in three patients with HHS from two unrelated families. RTEL1 is a DNA helicase that participates in DNA replication, DNA repair and telomere integrity. We show that, in addition to short telomeres, RTEL1-deficient cells from patients exhibit hallmarks of genome instability, including spontaneous DNA damage, anaphase bridges and telomeric aberrations. Collectively, these results identify RTEL1 as a novel HHS-causing gene and highlight its role as a genomic caretaker in humans

Development of primary early-onset colorectal cancers due to biallelic mutations of the FANCD1/BRCA2 gene

International audienceFanconi anaemia (FA) is characterized by progressive bone marrow failure, congenital anomalies, and predisposition to malignancy. In a minority of cases, FA results from biallelic FANCD1/BRCA2 mutations that are associated with early-onset leukaemia and solid tumours. Here, we describe the clinical and molecular features of a remarkable family presenting with multiple primary colorectal cancers (CRCs) without detectable mutations in genes involved in the Mendelian predisposition to CRCs. We unexpectedly identified, despite the absence of clinical cardinal features of FA, a biallelic mutation of the FANCD1/BRCA2 corresponding to a frameshift alteration (c.1845_1846delCT, p.Asn615Lysfs*6) and a missense mutation (c.7802A>G, p.Tyr2601Cys). The diagnosis of FA was confirmed by the chromosomal analysis of lymphocytes. Reverse transcriptase (RT)-PCR analysis revealed that the c.7802A>G BRCA2 variation was in fact a splicing mutation that creates an aberrant splicing donor site and results partly into an aberrant transcript encoding a truncated protein (p.Tyr2601Trpfs*46). The atypical FA phenotype observed within this family was probably explained by the residual amount of BRCA2 with the point mutation c.7802A>G in the patients harbouring the biallelic FANCD1/BRCA2 mutations. Although this report is based in a single family, it suggests that CRCs may be part of the tumour spectrum associated with FANCD1/BRCA2 biallelic mutations and that the presence of such mutations should be considered in families with CRCs, even in the absence of cardinal features of FA

Prednisone versus prednisone plus ciclosporin versus prednisone plus methotrexate in new-onset juvenile dermatomyositis: a randomised trial

Most data for treatment of dermatomyositis and juvenile dermatomyositis are from anecdotal, non-randomised case series. We aimed to compare, in a randomised trial, the efficacy and safety of prednisone alone with that of prednisone plus either methotrexate or ciclosporin in children with new-onset juvenile dermatomyositis.status: publishe

Prednisone versus prednisone plus ciclosporin versus prednisone plus methotrexate in new-onset juvenile dermatomyositis : a randomised trial

BACKGROUND: Most data for treatment of dermatomyositis and juvenile dermatomyositis are from anecdotal, non-randomised case series. We aimed to compare, in a randomised trial, the efficacy and safety of prednisone alone with that of prednisone plus either methotrexate or ciclosporin in children with new-onset juvenile dermatomyositis. METHODS: We did a randomised trial at 54 centres in 22 countries. We enrolled patients aged 18 years or younger with new-onset juvenile dermatomyositis who had received no previous treatment and did not have cutaneous or gastrointestinal ulceration. We randomly allocated 139 patients via a computer-based system to prednisone alone or in combination with either ciclosporin or methotrexate. We did not mask patients or investigators to treatment assignments. Our primary outcomes were the proportion of patients achieving a juvenile dermatomyositis PRINTO 20 level of improvement (20% improvement in three of six core set variables at 6 months), time to clinical remission, and time to treatment failure. We compared the three treatment groups with the Kruskal-Wallis test and Friedman's test, and we analysed survival with Kaplan-Meier curves and the log-rank test. Analysis was by intention to treat. Here, we present results after at least 2 years of treatment (induction and maintenance phases). This trial is registered with ClinicalTrials.gov, number NCT00323960. FINDINGS: Between May 31, 2006, and Nov 12, 2010, 47 patients were randomly assigned prednisone alone, 46 were allocated prednisone plus ciclosporin, and 46 were randomised prednisone plus methotrexate. Median duration of follow-up was 35·5 months. At month 6, 24 (51%) of 47 patients assigned prednisone, 32 (70%) of 46 allocated prednisone plus ciclosporin, and 33 (72%) of 46 administered prednisone plus methotrexate achieved a juvenile dermatomyositis PRINTO 20 improvement (p=0·0228). Median time to clinical remission was 41·9 months in patients assigned prednisone plus methotrexate but was not observable in the other two treatment groups (2·45 fold [95% CI 1·2-5·0] increase with prednisone plus methotrexate; p=0·012). Median time to treatment failure was 16·7 months in patients allocated prednisone, 53·3 months in those assigned prednisone plus ciclosporin, but was not observable in patients randomised to prednisone plus methotrexate (1·95 fold [95% CI 1·20-3·15] increase with prednisone; p=0·009). Median time to prednisone discontinuation was 35·8 months with prednisone alone compared with 29·4-29·7 months in the combination groups (p=0·002). A significantly greater proportion of patients assigned prednisone plus ciclosporin had adverse events, affecting the skin and subcutaneous tissues, gastrointestinal system, and general disorders. Infections and infestations were significantly increased in patients assigned prednisone plus ciclosporin and prednisone plus methotrexate. No patients died during the study. INTERPRETATION: Combined treatment with prednisone and either ciclosporin or methotrexate was more effective than prednisone alone. The safety profile and steroid-sparing effect favoured the combination of prednisone plus methotrexate. FUNDING: Italian Agency of Drug Evaluation, Istituto Giannina Gaslini (Genoa, Italy), Myositis Association (USA)

Genetic diagnosis of primary immunodeficiencies: A survey of the French national registry

International audienceTo the Editor:Since the mid-1980s, continuous progress in genetics and genomics has accelerated the rapid identification of causative genetic variants leading to primary immunodeficiencies (PIDs; >300 genes),1 with the noticeable exception of B-cell disorders, such as common variable immunodeficiency (CVID). The identification of these mutations not only validates a clinical diagnosis but also is useful in several other respects (more accurate prognosis on phenotype/genotype correlation, targeted therapy, and genetic counseling). [...