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Comparative Study
. 2005 Dec;77(6):1092-101.
doi: 10.1086/498454. Epub 2005 Oct 26.

NF1 gene mutations represent the major molecular event underlying neurofibromatosis-Noonan syndrome

Affiliations
Comparative Study

NF1 gene mutations represent the major molecular event underlying neurofibromatosis-Noonan syndrome

Alessandro De Luca et al. Am J Hum Genet. 2005 Dec.

Abstract

Neurofibromatosis type 1 (NF1) demonstrates phenotypic overlap with Noonan syndrome (NS) in some patients, which results in the so-called neurofibromatosis-Noonan syndrome (NFNS). From a genetic point of view, NFNS is a poorly understood condition, and controversy remains as to whether it represents a variable manifestation of either NF1 or NS or is a distinct clinical entity. To answer this question, we screened a cohort with clinically well-characterized NFNS for mutations in the entire coding sequence of the NF1 and PTPN11 genes. Heterozygous NF1 defects were identified in 16 of the 17 unrelated subjects included in the study, which provides evidence that mutations in NF1 represent the major molecular event underlying this condition. Lesions included nonsense mutations, out-of-frame deletions, missense changes, small inframe deletions, and one large multiexon deletion. Remarkably, a high prevalence of inframe defects affecting exons 24 and 25, which encode a portion of the GAP-related domain of the protein, was observed. On the other hand, no defect in PTPN11 was observed, and no lesion affecting exons 11-27 of the NF1 gene was identified in 100 PTPN11 mutation-negative subjects with NS, which provides further evidence that NFNS and NS are genetically distinct disorders. These results support the view that NFNS represents a variant of NF1 and is caused by mutations of the NF1 gene, some of which have been demonstrated to cause classic NF1 in other individuals.

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Figures

Figure  1
Figure 1
Facial characteristics and other clinical features of study individuals with NFNS
Figure  2
Figure 2
Three-dimensional model showing location of residues affected by mutations in the neurofibromin GAP-related domain/RAS complex. Ribbon-like structures of neurofibromin GAP-related domain and RAS are shown in green and yellow, respectively. The mutated residues (Lys1423, Asn1430, Val1432, and Glu1438), the catalytic arginine finger (Arg1276), and GDP are represented by sticks and transparent surfaces. Molecular alignment and representation were made with the programs SwissPdb Viewer v. 3.7 (Guex and Peitsch 1997) and PyMOL (DeLano 2002), respectively.

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References

Web Resources

    1. Human Gene Mutation Database, http://archive.uwcm.ac.uk/uwcm/mg/hgmd0.html
    1. Online Mendelian Inheritance in Man (OMIM), http://www.ncbi.nlm.nih.gov/Omim/ (for NFNS, NF1, NS, PTPN11, NL/MGCLS, and LS)
    1. PDB, http://www.rcsb.org/pdb/
    1. UCSC Genome Browser, http://genome.ucsc.edu/

References

    1. Abuelo DN, Meryash DL (1988) Neurofibromatosis with fully expressed Noonan syndrome. Am J Med Genet 29:937–94110.1002/ajmg.1320290426 - DOI - PubMed
    1. Allanson JE (1987) Noonan syndrome. J Med Genet 24:9–13 - PMC - PubMed
    1. Allanson JE, Hall JG, Van Allen MI (1985) Noonan phenotype associated with neurofibromatosis. Am J Med Genet 21:457–46210.1002/ajmg.1320210307 - DOI - PubMed
    1. Arun D, Gutmann DH (2004) Recent advances in neurofibromatosis type 1. Curr Opin Neurol 17:101–10510.1097/00019052-200404000-00004 - DOI - PubMed
    1. Bahuau M, Flintoff W, Assouline B, Lyonnet S, Le Merrer M, Prieur M, Guilloud-Bataille M, Feingold N, Munnich A, Vidaud M, Vidaud D (1996) Exclusion of allelism of Noonan syndrome and neurofibromatosis-type 1 in a large family with Noonan syndrome-neurofibromatosis association. Am J Med Genet 66:347–35510.1002/(SICI)1096-8628(19961218)66:3<347::AID-AJMG20>3.0.CO;2-L - DOI - PubMed

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