Neurofibromatosis type 1: New developments in genetics and treatment

An Atypical Mechanism of SUMOylation of Neurofibromin SecPH Domain Provides New Insights into SUMOylation Site Selection

Neurofibromin (Nf1) is a giant multidomain protein encoded by the tumour-suppressor gene NF1. NF1 is mutated in a common genetic disease, neurofibromatosis type I (NF1), and in various cancers. The protein has a Ras-GAP (GTPase activating protein) activity but is also connected to diverse signalling pathways through its SecPH domain, which interacts with lipids and different protein partners. We previously showed that Nf1 partially colocalized with the ProMyelocytic Leukemia (PML) protein in PML nuclear bodies, hotspots of SUMOylation, thereby suggesting the potential SUMOylation of Nf1. Here, we demonstrate that the full-length isoform 2 and a SecPH fragment of Nf1 are substrates of the SUMO pathway and identify a well-defined SUMOylation profile of SecPH with two main modified lysines. One of these sites, K1731, is highly conserved and surface-exposed. Despite the presence of an inverted SUMO consensus motif surrounding K1731, and a potential SUMO-interacting motif (SIM) within SecPH, we show that neither of these elements is necessary for K1731 SUMOylation, which is also independent of Ubc9 SUMOylation on K14. A 3D model of an interaction between SecPH and Ubc9 centred on K1731, combined with site-directed mutagenesis, identifies specific structural elements of SecPH required for K1731 SUMOylation, some of which are affected in reported NF1 pathogenic variants. This work provides a new example of SUMOylation dependent on the tertiary rather than primary protein structure surrounding the modified site, expanding our knowledge of mechanisms governing SUMOylation site selection.

A Comprehensive Overview of NF1 Mutations in Iranian Patients

Neurofibromatosis type 1 (NF1) is a genetic disorder caused by mutations in the NF1 gene. This disorder shows nearly complete penetrance and high phenotypic variability. We used the whole-exome sequencing technique to identify mutations in 32 NF1 cases from 22 Iranian families. A total of 31 variants, including 30 point mutations and one large deletion, were detected. In eight cases, variants were inherited, while they were sporadic in the remaining. Seven novel variants, including c.5576 T > G, c.6658_6659insC, c.2322dupT, c.92_93insAA, c.4360C > T, c.3814C > T, and c.4565_4566delinsC, were identified. The current study is the largest in terms of the sample size of Iranian NF1 cases with identified mutations. The results can broaden the spectrum of NF1 mutations and facilitate the process of genetic counseling in the affected families.

Imaging Update for Hereditary Abdominopelvic Neuroendocrine Neoplasms

ABSTRACT

Neuroendocrine neoplasms have shown a linear increase in incidence and prevalence in recent decades, primarily due to improved cross-sectional imaging, expanded use of endoscopic procedures, and advanced genetic analysis. However, diagnosis of hereditary neuroendocrine tumors is still challenging because of heterogeneity in their presentation, the variety of tumor locations, and multiple associated syndromes. Radiologists should be familiar with the spectrum of these tumors and associated hereditary syndromes. Furthermore, as the assessment of multiple tumor elements such as morphology, biochemical markers, and presence of metastatic disease are essential for the treatment plan, conventional anatomic and functional imaging methods are fundamental in managing and surveilling these cases. Our article illustrates the role of different cross-sectional imaging modalities in diagnosing and managing various hereditary abdominopelvic neuroendocrine tumors.

Genotype-phenotype correlations of neurofibromatosis type 1: a cross-sectional study from a large Chinese cohort

BACKGROUND

Neurofibromatosis type 1 (NF1) is a highly heterogeneous autosomal genetic disorder characterized by a broad spectrum of clinical and molecular manifestations. The correlations between genotype and phenotype in NF1 remain elusive. This study aimed to elucidate genotype-phenotype associations in a large Chinese cohort of NF1 patients.

METHODS

We included NF1 patients from our center who underwent genetic testing for NF1 variants and systemic examination. Genotype-phenotype correlation analyses were performed, focusing on variation types and involved neurofibromin domains.

RESULTS

A total of 195 patients were enrolled, comprising 105 males and 90 females, with a median age of 18 years. Truncating variants, single amino acid variations, and splicing variants accounted for 139/195 (71.3%), 23/195 (11.8%), and 33/195 (16.9%), respectively. Patients with splicing variants exhibited a significantly higher prevalence of spinal plexiform neurofibromas (spinal PNF) than those with truncating variants (76.4% vs. 51.8%; p = 0.022). Variations affecting the PKC domain were associated with higher rates of cutaneous neurofibromas (CNF) (100% vs. 64.9%, p < 0.001), Lisch nodules (100% vs. 61.2%, p < 0.001), plexiform neurofibromas (PNF) (100% vs. 95.7%, p = 0.009), and psychiatric disorders (11.8% vs. 1.6%, p = 0.042). Patients with mutations in the CSRD had an elevated risk of secondary primary malignancies (11.6% vs. 2.8%, p = 0.015). GRD involvement might enhance the risk of Lisch nodules (76.9% vs. 53.7%, p = 0.044). Variations in the Sec14-PH domain were correlated with a higher rate of CNF (76.8% vs. 58.6%, p = 0.014). Additionally, we found that the p.R1748* variants carry a high risk of malignancy.

CONCLUSION

Our study suggested some novel genotype-phenotype correlations within a Chinese cohort, providing innovative insights into this complex field that may contribute to genetic counseling, risk stratification, and clinical management for the NF1 population.

The role of scoliosis on the comorbidity and demographics of neurofibromatosis type 1 patients: A retrospective analysis of the National Inpatient Sample database

Neurofibromatosis type 1 (NF1) is the most common neurocutaneous syndrome in the United States, affecting every 1 in 3000 individuals. NF1 occurs due to non-functional mutations in the NF1 gene, which expresses neurofibromin, a protein involved in tumour suppression. As a result, NF1 typically presents with non-cancerous neoplasm masses called neurofibromas across the body. Out of all NF1 abnormalities, the most common skeletal abnormality seen in around 10%-30% of NF1 patients is scoliosis, an improver curvature of the spine. However, there is a lack of research on the effects of scoliosis on demographics and morbidities of NF1 patients. We performed a national analysis to investigate the complex relationship between NF1 and scoliosis on patients' demographics and comorbidities. We conducted a retrospective cross-sectional analysis of the 2017 US National Inpatient Sample database using univariable Chi-square analysis and multivariable binary logistic regression analysis to determine the interplay of NF1 and scoliosis on patients' demographics and comorbidities. Our query resulted in 4635 total NF1 patients, of which 475 (10.25%) had scoliosis and 4160 (89.75%) did not. Demographic analysis showed that NF1 patients with scoliosis were typically younger, female and white compared to NF1 patients without scoliosis. Comorbidity analysis showed that NF1 patients with scoliosis were more likely to develop malignant brain neoplasms, epilepsy, hydrocephalus, pigmentation disorders, hypothyroidism, diabetes with chronic complications and coagulopathy disorders. NF1 patients with scoliosis were less likely to develop congestive heart failure, pulmonary circulation disease, peripheral vascular disease, paralysis, chronic pulmonary disease, lymphoma and psychosis. NF1 patients with scoliosis were predominantly younger, female, white patients. The presence of scoliosis in NF1 patients increases the risks for certain brain neoplasms and disorders but serves a protective effect against some pulmonary and cardiac complications.

The Cardiofaciocutaneous Syndrome: From Genetics to Prognostic-Therapeutic Implications

Cardiofaciocutaneous (CFC) syndrome is one of the rarest RASopathies characterized by multiple congenital ectodermal, cardiac and craniofacial abnormalities with a mild to severe ocular, gastrointestinal and neurological involvement. It is an autosomal dominant syndrome, with complete penetrance, caused by heterozygous pathogenic variants in the genes BRAF, MAP2K1/MEK1, MAP2K2/MEK2, KRAS or, rarely, YWHAZ, all part of the RAS-MAPK pathway. This pathway is a signal transduction cascade that plays a crucial role in normal cellular processes such as cell growth, proliferation, differentiation, survival, metabolism and migration. CFC syndrome overlaps with Noonan syndrome, Costello syndrome, neurofibromatosis type 1 and Legius syndrome, therefore making the diagnosis challenging. Neurological involvement in CFC is more severe than in other RASopathies. Phenotypic variability in CFC patients is related to the specific gene affected, without a recognized genotype-phenotype correlation for distinct pathogenic variants. Currently, there is no specific treatment for CFC syndrome. Encouraging zebrafish model system studies suggested that, in the future, MEK inhibitors could be a suitable treatment of progressive phenotypes of CFC in children. A multidisciplinary care is necessary for appropriate medical management.

Nf1 in heart development: a potential causative gene for congenital heart disease: a narrative review

Congenital heart disease is the most frequent congenital disorder, affecting a significant number of live births. Gaining insights into its genetic etiology could lead to a deeper understanding of this condition. Although the Nf1 gene has been identified as a potential causative gene, its role in congenital heart disease has not been thoroughly clarified. We searched and summarized evidence from cohort-based and experimental studies on the issue of Nf1 and heart development in congenital heart diseases from various databases. Available evidence demonstrates a correlation between Nf1 and congenital heart diseases, mainly pulmonary valvar stenosis. The mechanism underlying this correlation may involve dysregulation of epithelial-mesenchymal transition (EMT). The Nf1 gene affects the EMT process via multiple pathways, including directly regulating the expression of EMT-related transcription factors and indirectly regulating the EMT process by regulating the MAPK pathway. This narrative review provides a comprehensive account of the Nf1 involvement in heart development and congenital cardiovascular diseases in terms of epidemiology and potential mechanisms. RAS signaling may contribute to congenital heart disease independently or in cooperation with other signaling pathways. Efficient management of both NF1 and cardiovascular disease patients would benefit from further research into these issues.

Periampullary tumors in a patient with pancreatic divisum and neurofibromatosis type 1: a case report

INTRODUCTION

We present a case of a male patient with neurofibromatosis type 1 diagnosed with pancreatic divisum and several gastrointestinal tumors. A 55-year-old man was admitted to the hospital with recurrent chronic pancreatitis, indicating a large mass in the ampulla. In addition, genetic testing revealed two unique germline mutations in the neurofibromin (NF1) gene, and their potential interaction in promoting cancer was further investigated.

CONCLUSION

The first similar case was reported in 2020. The current case was distinct from other cases since an additional two NF1 mutations were found in the patient. In conjunction with prior case reports, our findings imply that genetic testing in patients diagnosed with neurofibromatosis type 1 could be helpful in the development of effective treatments.

Neurofibromatosis 1 (von Recklinghausen Disease)

Neurofibromatosis 1 (NF1), also known as von Recklinghausen disease, is one of the most common neurocutaneous genetic disorders. Loss of function of the NF1 gene results in overactivation of the RAS/MAPK pathway, leading to neurocutaneous manifestations and osseous abnormalities. Because of medical progress, molecular testing for NF1 after genetic counseling is now available in Japan. In addition, revised diagnostic criteria for NF1 were proposed by NF1 experts of an international panel in 2021. Because the overall degree of severity and manifestations in each patient are not predictable, age-specific annual monitoring and patient education by a multidisciplinary team are important for the management of NF1. Although treatment of plexiform neurofibroma has been challenging, selumetinib (an oral selective MEK1/2 inhibitor), which targets a pathway downstream of RAS, was approved in 2022 for use in children with inoperable, symptomatic plexiform neurofibromas in Japan. This article summarizes recent progress in diagnosis, clinical characteristics, and treatment of various manifestations of NF1 and proposes the future direction required to resolve unmet needs in patients with NF1 in Japan.

A case of solitary digital glomus tumor associated with neurofibromatosis type 1

An association between glomus tumor and neurofibromatosis type 1 has been reported. It is characterized by multiple tumors and young age at onset. The early diagnosis of neurofibromatosis type 1 is important because it is associated with a high rate of malignancy. A 25-year-old man presented to our hospital with left index finger pain that had persisted for 6 years. Physical and imaging findings suggested a benign soft-tissue tumor. Surgery was performed, and the tumor was pathologically diagnosed as glomus tumor. In this case, the patient with a young-onset glomus tumor was suspected of having neurofibromatosis type 1. An additional medical examination led to the diagnosis of unrecognized neurofibromatosis type 1. We experienced a case in which the onset of a glomus tumor led to the diagnosis of neurofibromatosis type 1. Comorbid neurofibromatosis type 1 should be kept in mind when glomus tumors are diagnosed.

Superimposed Mosaicism in the Form of Extremely Extended Segmental Plexiform Neurofibroma Caused by a Novel Pathogenic Variant in the NF1 Gene

Plexiform neurofibromas occurring in approximately 20-50% of all neurofibromatosis type-1 (NF1) cases are histologically benign tumors, but they can be fatal due to compression of vital structures or transformation to malignant sarcomas or malignant peripheral nerve sheath tumors. All sizeable plexiform neurofibromas are thought to result from an early second mutation giving rise to a loss of heterozygosity of the NF1 gene. In this unusual case, a 12-year-old girl presented with a rapidly growing, extremely extensive plexiform neurofibroma with segmental distribution over the entire right arm, extending to the right chest wall and mediastinum, superimposed on classic cutaneous lesions of NF1. After several surgical interventions, the patient was efficiently treated with an oral selective MEK inhibitor, selumetinib, which resulted in a rapid reduction of the tumor volume. Molecular analysis of the NF1 gene revealed a c.2326-2 A>G splice-site mutation in the clinically unaffected skin, peripheral blood sample, and plexiform neurofibroma, which explains the general clinical symptoms. Furthermore, a novel likely pathogenic variant, c.4933dupC (p.Leu1645Profs*7), has been identified exclusively in the girl's plexiform neurofibromas. This second-hit mutation can explain the extremely extensive segmental involvement.

Dermatologic Manifestations of Neurofibromatosis Type 1 and Emerging Treatments

Neurofibromatosis type 1 (NF1) is an autosomal dominant tumor predisposition syndrome that increases one's risk for both benign and malignant tumors. NF1 affects every organ in the body, but the most distinctive symptoms that are often the most bothersome to patients are the cutaneous manifestations, which can be unsightly, cause pain or pruritus, and have limited therapeutic options. In an effort to increase awareness of lesser-known dermatologic associations and to promote multidisciplinary care, we conducted a narrative review to shed light on dermatologic associations of NF1 as well as emerging treatment options. Topics covered include cutaneous neurofibromas, plexiform neurofibromas, diffuse neurofibromas, distinct nodular lesions, malignant peripheral nerve sheath tumors, glomus tumors, juvenile xanthogranulomas, skin cancer, and cutaneous T-cell lymphoma.

Portal cavernoma in type 1 neurofibromatosis: A fortuitous or causal association?

Neurofibromatosis type 1 (NF-1) is a multisystem genetic disorder affecting the NF1 tumor suppressor gene. Patients typically develop superficial (cutaneous) and internal (plexiform) neurofibromas. The latter may rarely involve the liver locating in the hilum and encasing the portal vessels, leading to portal hypertension. Vascular abnormalities (NF-I vasculopathy) are a well-recognized manifestation of NF-1. Although the pathogenesis is not well-known, NF-1 vasculopathy involves arteries of both peripheral and cerebral territories, with venous thrombosis being exceptionally reported. Portal venous thrombosis (PVT) is the leading cause of portal hypertension in childhood and has been associated with several risk factors. Nevertheless, predisposing conditions remain unknown in more than 50% of the cases. The treatment options are limited, and its management is nonconsensual in the pediatric age. We report the case of a 9-year-old boy with clinically and genetically confirmed NF-1, diagnosed with portal venous cavernoma after an episode of gastrointestinal bleeding. There were no identifiable risk factors for PVT and intrahepatic peri-hilar plexiform neurofibroma was excluded by MRI imaging. To the best of our knowledge, this is the first report of PVT in NF-1. We speculate that NF-1 vasculopathy may have been a pathogenic factor, or instead, it was a fortuitous association.

Blue Nail Discoloration: Literature Review and Diagnostic Algorithms

Blue nail discoloration is a distinctive clinical presentation, and diagnosis is challenging given the broad differential diagnosis. A comprehensive review of the literature describing blue discoloration of one or multiple nails was performed using the PubMed, Embase, Scopus, and Web of Science databases. A total of 245 publications were included and grouped based on involvement of a single nail (monodactylic) or multiple nails (polydactylic). Monodactylic blue discoloration was associated with tumors or benign nevi, most commonly glomus tumors, followed by blue nevi and less commonly melanomas. Polydactylic blue discoloration was frequently associated with medications (such as minocycline, zidovudine, and hydroxyurea), toxic and exogenous exposures (such as silver), and other medical conditions (such as HIV/AIDS and systemic lupus erythematous). Patients presenting with blue nail discoloration warrant a thorough history, physical examination, and workup to rule out malignancy, systemic disease, or toxic exposure. We present diagnostic algorithms for monodactylic and polydactylic blue nail discoloration to guide workup and treatment plans.

Eating disorders in young patients with neurofibromatosis type 1

AIM

We describe the association of neurofibromatosis type 1 (NF1) and feeding and eating disorders (FED) in five patients admitted to our third level centre for both FED and NF1.

METHODS

Case series of five adolescent females with NF1 treated for FED.

RESULTS

We collected data from five patients with NF1 aged between 14 and 22 years, all females. The onset of eating disorder symptoms occurred between 13 and 19 years of age and was characterised by food intake restriction, associated with physical hyperactivity in three out of five cases. One patient also reported self-injurious acts and episodic binges. Patients received diagnoses of anorexia nervosa (AN, n = 2), atypical AN (n = 1), bulimia nervosa (n = 1), unspecified feeding and eating disorder (n = 1).

CONCLUSION

The current literature reports a single case of an adult with NF1 and comorbid AN, focusing on the dermatological features of NF1. Our article describes a case series of five patients in developmental age affected by NF1 and FED. Clinical and psychological features of NF1 may play a role in the pathogenesis of FED when these two conditions co-occur. The dermatological alterations of NF1 may contribute to body image distortion that characterises AN. Further research is required to systematically screen populations of patients with NF1 for the presence of FED.

Case report: Gene mutation analysis and skin imaging of isolated café-au-lait macules

Background: Café-au-lait macules (CALMs) are common birthmarks associated with several genetic syndromes, such as neurofibromatosis type 1 (NF1). Isolated CALMs are defined as multiple café-au-lait macules in patients without any other sign of NF1. Typical CALMs can have predictive significance for NF1, and non-invasive techniques can provide more accurate results for judging whether café-au-lait spots are typical. Objectives: The study aimed to investigate gene mutations in six Chinese Han pedigrees of isolated CALMs and summarize the characteristics of CALMs under dermoscopy and reflectance confocal microscopy (RCM). Methods: In this study, we used Sanger sequencing to test for genetic mutations in six families and whole exome sequencing (WES) in two families. We used dermoscopy and RCM to describe the imaging characteristics of CALMs. Results: In this study, we tested six families for genetic mutations, and two mutations were identified as novel mutations. The first family identified [NC_000017.11(NM_001042492.2):c.7355G>A]. The second family identified [NC_000017.11(NM_001042492.2):c.2739_2740del]. According to genotype-phenotype correlation analyses, proband with frameshift mutation tended to have a larger number of CALMs and a higher rate of having atypical CALMs. Dermoscopy showed uniform and consistent tan-pigmented network patches with poorly defined margins with a lighter color around the hair follicles. Under RCM, the appearance of NF1 comprised the increased pigment granules in the basal layer and significantly increased refraction. Conclusion: A new heterozygous mutation and a new frameshift mutation of NF1 were reported. This article can assist in summarizing the properties of dermoscopy and RCM with CALMs.

Case report: Neurofibromatosis type 1 gastrointestinal stromal tumor and small bowel adenocarcinoma with a novel germline NF1 frameshift mutation

A synchronous case of small bowel adenocarcinoma(SAB) is reported, accompanied with gastrointestinal stromal tumor(GIST),and gangliocytomain in an elderly woman with neurofibromatosis type 1 (NF-1). A 67-year-old female was hospitalized with the chief complaint of abdominal pain, the computed tomography scan indicated a large bowel mass. Multiple tumors were found in the small intestine, through which two larger tumors (7 cm and 1.5 cm) were resected. A novel germline NF1 mutation and a PMS2 mutation were identified after genetic testing, followed by the exploration of possible relationship between them in promoting tumorigenesis. Our results suggest multiple gastrointestinal tumors emerging in NF1 patients, and genetic testing can better guide postoperative treatment in a more efficient way.

Selumetinib: a selective MEK1 inhibitor for solid tumor treatment

Cancer incidence is rapidly growing. Solid tumors are responsible for a majority of cancers. Recently, molecular-targeted agents have played a significant role in cancer treatment. Ras-Raf-MEK-ERK signaling pathway, is a substantial element in the survival, propagation, and drug resistance of human cancers. MEK is a specific part of the so-called cascade, and ERK proteins are its sole target. Furthermore, their downstream position in the Ras-ERK cascade, is noteworthy to direct their function in patients with upstream mutated genes. MEK1 mutations are responsible for initiating several solid tumors. Selumetinib (AZD6244) is a second-generation, selective, potent, and non-ATP competitive allosteric MEK1 inhibitor. The efficacy of selumetinib in various solid tumors such as colorectal cancer, lung cancer, neurofibroma, and melanoma is investigated. The present paper provides an overview of the MAPK cascade, the role of selumetinib as a MEK1/2 inhibitor, and the related findings of clinical trials for solid tumor treatment.

Psychosocial profiles of risk and resiliency in neurofibromatoses: a person-centered analysis of illness adaptation

OBJECTIVES

We sought to characterize psychosocial profiles of adaptation to neurofibromatosis (NF).

METHODS

Participants (N = 224) completed self-report measures of psychosocial functioning, including risk (i.e., perceived stress, depression, anxiety) and resiliency (i.e., gratitude, optimism, coping, social support, mindfulness, empathy). We used a TwoStep hierarchical cluster analysis to determine clusters reflecting adaptation to NF.

RESULTS

The analysis revealed two distinct groups, with the "Low Adaptation" group defined by high emotional distress and low resiliency (n = 130; 57% of participants), and the "High Adaptation" group defined by low emotional distress and high resiliency (n = 85; 37% of participants). Clusters differed significantly across nearly all criterion variables, as well as quality of life and pain interference.

CONCLUSION

Both risk and resiliency factors are important for understanding psychosocial adaptation to NF. Findings suggest that clinical providers should prioritize screening and intervention methods targeting these variables to promote positive adaptation to NF.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03406208; https://clinicaltrials.gov/ct2/show/NCT03406208 (Archived by WebCite at http://www.webcitation.org/72ZoTDQ6h ).

Neurofibromatosis Type 1 Gene Alterations Define Specific Features of a Subset of Glioblastomas

Neurofibromatosis type 1 (NF1) gene mutations or alterations occur within neurofibromatosis type 1 as well as in many different malignant tumours on the somatic level. In glioblastoma, NF1 loss of function plays a major role in inducing the mesenchymal (MES) subtype and, therefore defining the most aggressive glioblastoma. This is associated with an immune signature and mediated via the NF1–MAPK–FOSL1 axis. Specifically, increased invasion seems to be regulated via mutations in the leucine-rich domain (LRD) of the NF1 gene product neurofibromin. Novel targets for therapy may arise from neurofibromin deficiency-associated cellular mechanisms that are summarised in this review.

Chronic Lymphocytic Leukemia in Neurofibromatosis Type 1 Patients: Case Report and Literature Review of a Rare Occurrence

Neurofibromatosis type 1 (NF1) is an autosomal dominant genodermatosis that may also occur as the result of a spontaneous mutation. The diagnosis can be established by the presence of two of the seven National Institutes of Health (NIH) diagnostic criteria; several dermatologic manifestations are NIH criteria used to establish the diagnosis: axillary and inguinal freckling, café-au-lait macules, and neurofibromas. Mucosal evaluation of the eyes may detect a fourth criteria: pigmented iris hamartomas (Lisch nodules). The remaining NIH criteria include optic path glioma, distinctive osseus lesions, and a positive family history of the condition. A breast cancer 2 (BRCA2) positive woman with NF1 and chronic lymphocytic leukemia is described. Patients with NF1 have an increased lifetime risk to develop breast cancer, gastrointestinal stromal tumor, malignant glioma, malignant peripheral nerve sheath tumor, and rhabdomyosarcoma. Chronic lymphocytic leukemia occurring in NF1 patients is rare; including my female patient reported in this paper, chronic lymphocytic leukemia has only been reported in three individuals with NF1--two women and one man. The man and the other woman presented with advanced chronic lymphocytic leukemia and treatment with antineoplastic therapy at diagnosis; the man achieved clinical remission and the woman passed away from complications associated with therapy-refractory progression of her leukemia. My female patient required treatment 41 months after diagnosis and had a good clinical response; she has been without significant disease progression for 34 months. Similar to NF1, breast cancer 1 (BRCA1) and BRCA2 mutations are associated with an increased lifetime risk of developing cancer--particularly breast and ovarian carcinoma. An increased risk of chronic lymphocytic leukemia has also been demonstrated in patients with mutations of either BRCA1 or BRCA2. Also, albeit uncommon, either BRCA1 or BRCA2 mutation has been detected in women with NF1 who develop breast cancer. In conclusion, the development of chronic lymphocytic leukemia in NF1 patients may be coincidental and not associated with the underlying genodermatosis; however, the occurrence of chronic lymphocytic leukemia in my patient with NF1, in part, may be related to her BRCA2 positivity.