Screening 500 unselected neurofibromatosis 1 patients for deletions of the
            <i>NF1</i>
            gene

Kluwe, Lan; Siebert, Reiner; Gesk, Stefan; Friedrich, Reinhard E; Tinschert, Sigrid; Kehrer‐Sawatzki, Hildegard; Mautner, Victor‐F.

doi:10.1002/humu.10299

Cited by 159 publications

(121 citation statements)

References 33 publications

Supporting

Mentioning

109

Contrasting

Unclassified

Order By: Relevance

“…In this Italian cohort, we describe 11 cases with a type 1 microdeletion (Kluwe et al. 2004) and two type 3 microdeletions (Bengesser et al. 2010), but no type 2 microdeletions (Kehrer‐Sawatzki et al.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

126 novel mutations in Italian patients with neurofibromatosis type 1

Bianchessi¹,

Morosini²,

Saletti³

et al. 2015

Molec Gen & Gen Med

View full text Add to dashboard Cite

Genetic analysis of Neurofibromatosis type 1 (NF1) may facilitate the identification of patients in early phases of the disease. Here, we present an overview of our diagnostic research spanning the last 11 years, with a focus on the description of 225 NF1 mutations, 126 of which are novel, found in a series of 607 patients (513 unrelated) in Italy. Between 2003 and 2013, 443 unrelated patients were profiled by denaturing high pressure liquid chromatography (DHPLC) analysis of 60 amplicons derived from genomic NF1 DNA and subsequent sequencing of heterozygotic PCR products. In addition, a subset of patients was studied by multiplex ligation‐dependent probe amplification (MLPA) to identify any duplications, large deletions or microdeletions present at the locus. Over the last year, 70 unrelated patients were investigated by MLPA and sequencing of 22 amplicons spanning the entire NF1 cDNA. Mutations were found in 70% of the 293 patients studied by DHPLC, thereby fulfilling the NIH criterion for the clinical diagnosis of NF1 (detection rate: 70%); furthermore, 87% of the patients studied by RNA sequencing were genetically characterized. Mutations were also found in 36 of the 159 patients not fulfilling the NIH clinical criteria. We confirmed a higher incidence of intellectual disability in patients harboring microdeletion type 1 and observed a correlation between a mild phenotype and the small deletion c.2970_2972delAAT or the missense alteration in amino acid residue 1809 (p.Arg1809Cys). These data support the use of RNA‐based methods for genetic analysis and provide novel information for improving the management of symptoms in oligosymptomatic patients.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Between 5% and 10% of these changes were characterized by microdeletion of the entire NF1 gene and contiguous genes (1–1.4 Mb) (Kluwe et al. 2004). Insertion and copy number alterations were reported less frequently in the literature (Kehrer‐sawatzki et al.…”

Section: Introductionmentioning

confidence: 99%

126 novel mutations in Italian patients with neurofibromatosis type 1

Bianchessi¹,

Morosini²,

Saletti³

et al. 2015

Molec Gen & Gen Med

View full text Add to dashboard Cite

show abstract

“…All five changes involved single nucleotide substitutions. It is unclear why these alterations were not identified in the initial heteroduplex screen.To determine whether the remaining 44 patients carried gross deletions in the gene, they were analyzed for LOH at microsatellite repeat loci known to be useful in this regard [Kluwe et al, 2004]. Of the seven markers identified by Kluwe and others [2004], five were used in the present study.…”

mentioning

confidence: 99%

“…Of the seven markers identified by Kluwe and others [2004], five were used in the present study. The probability of all five loci being homozygous in an individual was estimated to be 0.0005 (see [Kluwe et al, 2004]) representing a very rear occurrence. Although the majority of individuals were heterozygous at one or more microsatellite loci, five (samples 35, 38, 50, 63 and 145; Table 1) were identified to be "homozygous" at all loci.…”

mentioning

confidence: 99%

“…None-the-less, neither DHPLC nor direct sequencing can be used to detect gross genetic deletion or insertion. By demonstrating loss of heterozgosity (LOH) at microsatellite loci within the NF1 gene, Kluwe and co-workers were able to detect mutations in 96% (22/23) of patients with large deletions [Kluwe et al, 2004]. Quantitative PCR (Q-PCR) measurements, used to detect 17p11.2 duplication in Charcot-Marie-Tooth disease [Wilke et al, 2000;Choi et al, 2005], provides another method for detecting gross mutations in the NF1 gene (e.g., deletions and duplications).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Identification of forty-five novel and twenty-three knownNF1 mutations in Chinese patients with neurofibromatosis type 1

Lee

You

et al. 2006

Hum. Mutat.

View full text Add to dashboard Cite

Neurofibromatosis type 1 (NF1), characterized by skin neurofibromas and an excess of café-au-lait spots, is due to mutations in the neurofibromin (NF1) gene. Identifying the genetic defect in individuals with the disease represents a significant challenge because the gene is extremely large with a high incidence of sporadic mutations across the entire gene ranging from single nucleotide substitutes to large deletions. In the present study, we have used a combination of techniques (heteroduplex analysis, sequencing, loss of heterozygosity and quantification of gene dosage) to define the genetic defect in 68 individuals from a cohort of 107 NF1 Taiwanese patients of Chinese origin. Fifty-eight were initially identified using heteroduplex analytical techniques and confirmed by sequence analysis. A further five were identified by direct sequence analysis alone. The reminders were shown to carry large deletions in the NF1 gene by demonstrating loss of heterozygosity that was confirmed by gene dosage measurements using quantitative-PCR techniques. Mis-sense, non-sense, frameshift or splice-site mutations were identified across the entire gene of which the majority (45/68) were novel in nature. The detection rate with the various analytical techniques and the types of mutation detected are consistent with published data involving both individuals and large cohort studies from other ethnic backgrounds. INTRODUCTIONWith a frequency of 1/3000 live births, Neurofibromatosis type 1 (NF1; MIM# 162200) is one of the most common autosomal dominant disorders involving the human nervous system [Friedman, 1999]. The clinical features of the disease include: café-au-lait spots, cutaneous or subcutaneous neurofibromas, large plexiform neurofibromas, Lisch nodules and skin freckling. Other features such as scoliosis, macrocephaly, pseudoarthrosis, short stature, mental sub-normality and malignancies are present in a minority of patients 1997]. Except for the discoloration of the skin (Café-au-lait macules), which can be identified at a very young age, most of the other clinical features usually occur insidiously after puberty.The NF1 gene (NM_000267.1), which spans approximately 350Kb of genomic sequence on chromosome 17q11.2, is composed of 60 exons coding an 8.9Kb mRNA [Cawthon et al., 1990a;Wallace et al., 1990]. NF1 gene product, neurofibromin, is a 250 KDa hydrophilic protein comprising 2818 amino acids [Cawthon et al., 1990b]. The central region of neurofibromin displays marked homology with Ras-GTPase activation proteins (GAPs) that are involved in the negative regulation of RAS-mediated signal transduction pathways [Cichowski and Jacks, 2001].The mutation rate at the NF1 gene is estimated to be ~1x10 -4 /gamete/generation making it one of the highest of any human disease genes [Huson et al., 1989;Upadhyaya and Cooper, 1998]. Mutations encompass both single nucleotide substitutions and large genomic deletions [Stenson et al., 2003]. Approximately a half of all mutations arise de novo and do not appear to be clustered within...

show abstract