Also found in: Acronyms, Wikipedia.


A gene on chromosome 17q11.2 that encodes neurofibromin 1, a protein which stimulates GTPase activity of Ras and may regulate Ras activity.

Molecular pathology
NF1 defects cause:
• Familial spinal neurofibromatosis;
• Juvenile myelomonocytic leukaemia;
• Neurofibromatosis type 1;
• Neurofibromatosis-Noonan syndrome;
• Watson syndrome; and
• Some cases of colorectal carcinoma.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


(nū″rō-fī-brō′mĭn, noo″) [″ + ″]
A tumor suppressor protein whose expression is reduced in the neurons of patients with neurofibromatosis and increased in the skin of patients who suffer tissue trauma.
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
Mahalingam, "NF1 and Neurofibromin: Emerging Players in the Genetic Landscape of Desmoplastic Melanoma," Advances in Anatomic Pathology, vol.
The NF1 is a tumor suppressor gene encoding a RAS GTPase-activating protein called neurofibromin, which is a large multi-domain 2818 amino acid protein.[sup][5] Hitherto, more than 2000 various causative mutations of NF1 gene associated with NF1 have been recorded in the HGMD database including missense, nonsense, splice-site, and frameshift mutations.
Zhang et al., "Neurofibromin is a novel regulator of Ras-induced reactive oxygen species production in mice and humans," Free Radical Biology & Medicine, vol.
Injection of adenovirus expressing Cre into mice carrying floxed alleles of Nf1 and Cdkn2a drives high-grade MPNST through localized loss of neurofibromin, [p16.sup.Ink4a], and [p19.sup.Arf] in the nerve [86].
(5) in their report on an adult with neurofibromatosis type 1 who developed chronic myeloid leukemia suggest a possible synergistic action between the absence of neurofibromin and the presence of tyrosine kinase activity of BCR/ABL gene.
[4] Human genes: NF1, neurofibromin 1; RET, ret protooncogene; VHL, von Hippel-Lindau tumor suppressor, E3 ubiquitin protein ligase; SDHB, succinate dehydrogenase complex, subunit B, iron sulfur (Ip); SDHD, succinate dehydrogenase complex, subunit D, integral membrane protein.
It has recently been shown that neurofibromatosis 1 (NF1) is associated with a defect in the neurofibromin gene on chromosome 17 and NF2 with a defect in the merlin/ schwannomin gene on chromosome 22.
Regulation of neurofibromin by post- translational modification.
Diagnosis of the autosomal dominant syndrome--which results from a neurofibromin defect and occurs in 1 of 2,000-4,500 individuals--requires the presence of two or more of the following diagnostic criteria: six or more CALMs greater than 0.5 cm in diameter in prepubertal children, or greater than 1.5 cm in those postpubertal; two or more neurofibromas of any type, or one plexiform neurofibroma; axillary and/or inguinal freckling (Crowe's sign); optic glioma; two or more Lisch nodules; a bony lesion (such as sphenoid dysplasia or long bone dysplasia); and a first-degree relative with NF1.

Full browser ?