Improved sensitivity for detection of pathogenic variants in familial NF2-related schwannomatosis

PURPOSE

To determine the impact of additional genetic screening techniques on the rate of detection of pathogenic variants leading to familial NF2-related schwannomatosis.

METHODS

We conducted genetic screening of a cohort of 168 second-generation individuals meeting the clinical criteria for NF2-related schwannomatosis. In addition to the current clinical screening techniques, targeted next-generation sequencing (NGS) and multiplex ligation-dependent probe amplification analysis, we applied additional genetic screening techniques, including karyotype and RNA analysis. For characterisation of a complex structural variant, we also performed long-read sequencing analysis.

RESULTS

Additional genetic analysis resulted in increased sensitivity of detection of pathogenic variants from 87% to 95% in our second-generation NF2-related schwannomatosis cohort. A number of pathogenic variants identified through extended analysis had been previously observed after NGS analysis but had been overlooked or classified as variants of uncertain significance.

CONCLUSION

Our study indicates there is added value in performing additional genetic analysis for detection of pathogenic variants that are difficult to identify with current clinical genetic screening methods. In particular, RNA analysis is valuable for accurate classification of non-canonical splicing variants. Karyotype analysis and whole genome sequencing analysis are of particular value for identification of large and/or complex structural variants, with additional advantages in the use of long-read sequencing techniques.

Patient-reported measures of tinnitus for individuals with neurofibromatosis type 2-related schwannomatosis: Recommendations for clinical trials

BACKGROUND

Neurofibromatosis type 2-related schwannomatosis is a genetic disease characterized by the development of bilateral vestibular schwannomas, ependymomas, meningiomas, and cataracts. Mild to profound hearing loss and tinnitus are common symptoms reported by individuals with neurofibromatosis type 2. While tinnitus is known to have a significant and negative impact on the quality of life of individuals from the general population, the impact on individuals with neurofibromatosis type 2 is unknown. Consensus regarding the selection of suitable patient-reported outcome measures for assessment could advance further research into tinnitus in neurofibromatosis type 2 patients. The purpose of this work is to achieve a consensus recommendation by the Response Evaluation in Neurofibromatosis and Schwannomatosis International Collaboration for patient-reported outcome measures used to evaluate quality of life in the domain of tinnitus for neurofibromatosis type 2 clinical trials.

METHODS

The Response Evaluation in Neurofibromatosis and Schwannomatosis Patient-Reported Outcomes Communication Subgroup systematically evaluated patient-reported outcome measures of quality of life in the domain of tinnitus for individuals with neurofibromatosis type 2 using previously published Response Evaluation in Neurofibromatosis and Schwannomatosis rating procedures. Of the 19 identified patient-reported outcome measures, 3 measures were excluded because they were not validated as an outcome measure or could not have been used as a single outcome measure for a clinical trial. Sixteen published patient-reported outcome measures for the domain of tinnitus were scored and compared on their participant characteristics, item content, psychometric properties, and feasibility for use in clinical trials.

RESULTS

The Tinnitus Functional Index was identified as the most highly rated measure for the assessment of tinnitus in populations with neurofibromatosis type 2, due to strengths in the areas of item content, psychometric properties, feasibility, and available scores.

DISCUSSION

Response Evaluation in Neurofibromatosis and Schwannomatosis currently recommends the Tinnitus Functional Index for the assessment of tinnitus in neurofibromatosis type 2 clinical trials.

Gene-targeted therapy for neurofibromatosis and schwannomatosis: The path to clinical trials

Numerous successful gene-targeted therapies are arising for the treatment of a variety of rare diseases. At the same time, current treatment options for neurofibromatosis 1 and schwannomatosis are limited and do not directly address loss of gene/protein function. In addition, treatments have mostly focused on symptomatic tumors, but have failed to address multisystem involvement in these conditions. Gene-targeted therapies hold promise to address these limitations. However, despite intense interest over decades, multiple preclinical and clinical issues need to be resolved before they become a reality. The optimal approaches to gene-, mRNA-, or protein restoration and to delivery to the appropriate cell types remain elusive. Preclinical models that recapitulate manifestations of neurofibromatosis 1 and schwannomatosis need to be refined. The development of validated assays for measuring neurofibromin and merlin activity in animal and human tissues will be critical for early-stage trials, as will the selection of appropriate patients, based on their individual genotypes and risk/benefit balance. Once the safety of gene-targeted therapy for symptomatic tumors has been established, the possibility of addressing a wide range of symptoms, including non-tumor manifestations, should be explored. As preclinical efforts are underway, it will be essential to educate both clinicians and those affected by neurofibromatosis 1/schwannomatosis about the risks and benefits of gene-targeted therapy for these conditions.

Perspectives of adults with neurofibromatosis regarding the design of psychosocial trials: Results from an anonymous online survey

BACKGROUND/AIMS

Individuals with neurofibromatosis, including neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2)-related schwannomatosis (SWN), and other forms of SWN, often experience disease manifestations and mental health difficulties for which psychosocial interventions may help. An anonymous online survey of adults with neurofibromatosis assessed their physical, social, and emotional well-being and preferences about psychosocial interventions to inform clinical trial design.

METHODS

Neurofibromatosis clinical researchers and patient representatives from the Response Evaluation in Neurofibromatosis and Schwannomatosis International Collaboration developed the survey. Eligibility criteria included age ≥ 18 years, self-reported diagnosis of NF1, NF2, or SWN, and ability to read and understand English. The online survey was distributed internationally by the Neurofibromatosis Registry and other neurofibromatosis foundations from June to August 2020.

RESULTS

Surveys were completed by 630 adults (18-81 years of age; M = 45.5) with NF1 (78%), NF2 (14%), and SWN (8%) who were mostly White, not Hispanic/Latino, female, and from the United States. The majority (91%) reported that their neurofibromatosis symptoms had at least some impact on daily life. In the total sample, 51% endorsed a mental health diagnosis, and 27% without a diagnosis believed they had an undiagnosed mental health condition. Participants indicated that neurofibromatosis affected their emotional (44%), physical (38%), and social (35%) functioning to a high degree. Few reported ever having participated in a drug (6%) or psychosocial (7%) clinical trial, yet 68% reported they "probably" or "definitely" would want to participate in a psychosocial trial if it targeted a relevant concern. Top treatment targets were anxiety, healthier lifestyle, and daily stress. Top barriers to participating in psychosocial trials were distance to clinic, costs, and time commitment. Respondents preferred interventions delivered by clinicians via individual sessions or a combination of group and individual sessions, with limited in-person and mostly remote participation. There were no significant group differences by neurofibromatosis type in willingness to participate in psychosocial trials (p = 0.27). Regarding interest in intervention targets, adults with SWN were more likely to prefer psychosocial trials for pain support compared to those with NF1 (p < 0.001) and NF2 (p < 0.001).

CONCLUSION

This study conducted the largest survey assessing physical symptoms, mental health needs, and preferences for psychosocial trials in adults with neurofibromatosis. Results indicate a high prevalence of disease manifestations, psychosocial difficulties, and untreated mental health problems in adults with neurofibromatosis and a high degree of willingness to participate in psychosocial clinical trials. Patient preferences should be considered when designing and implementing psychosocial interventions to develop the most feasible and meaningful studies.

Recommendations for the collection and annotation of biosamples for analysis of biomarkers in neurofibromatosis and schwannomatosis clinical trials

INTRODUCTION

Neurofibromatosis 1 and schwannomatosis are characterized by potential lifelong morbidity and life-threatening complications. To date, however, diagnostic and predictive biomarkers are an unmet need in this patient population. The inclusion of biomarker discovery correlatives in neurofibromatosis 1/schwannomatosis clinical trials enables study of low-incidence disease. The implementation of a common data model would further enhance biomarker discovery by enabling effective concatenation of data from multiple studies.

METHODS

The Response Evaluation in Neurofibromatosis and Schwannomatosis biomarker working group reviewed published data on emerging trends in neurofibromatosis 1 and schwannomatosis biomarker research and developed recommendations in a series of consensus meetings.

RESULTS

Liquid biopsy has emerged as a promising assay for neurofibromatosis 1/schwannomatosis biomarker discovery and validation. In addition, we review recommendations for a range of biomarkers in clinical trials, neurofibromatosis 1/schwannomatosis-specific data annotations, and common data models for data integration.

CONCLUSION

These Response Evaluation in Neurofibromatosis and Schwannomatosis consensus guidelines are intended to provide best practices for the inclusion of biomarker studies in neurofibromatosis 1/schwannomatosis clinical trials, data, and sample annotation and to lay a framework for data harmonization and concatenation between trials.

Management of Central and Peripheral Nervous System Tumors in Patients with Neurofibromatosis

Neurofibromatosis type I (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis represent a diverse group of genetic tumor predisposition syndromes with a shared feature of tumors affecting the peripheral nerve sheaths. PURPOSE OF REVIEW: Many advancements have been made in understanding the biologic underpinnings of these conditions, and in 2016 the first drug was approved by the FDA to treat pediatric symptomatic unresectable plexiform neurofibromas. RECENT FINDINGS: Mek inhibitors have provided a much-needed therapeutic avenue for NF1 patients with unresectable plexiform neurofibromas (PN), both for reduction of tumor bulk and for improvement in symptoms. Selumetinib is the first FDA approved drug for PN, but is only approved for children. Some research suggests that alternative Mek inhibitors and other mixed tyrosine kinase inhibitors may have better efficacy in adults. Vascular endothelial growth factor (VEGF) inhibitor bevacizumab can prolong hearing and delay the need for surgery in NF2 patients with bilateral vestibular schwannomas. This article provides an update regarding considerations and approaches when treating the tumors associated with the neurofibromatoses (NF), including risk and prognosis metrics, clinical trial results, surgical techniques, and radiation therapy recommendations.

A Novel Heterozygous NF1 Variant in a Neurofibromatosis-Noonan Syndrome Patient with Growth Hormone Deficiency: A Case Report

Neurofibromatosis-Noonan syndrome (NFNS), a rare autosomal-dominant hereditary disease, is characterized by clinical manifestations of both neurofibromatosis type 1 (NF1) and NS. We present a case of NFNS with short stature caused by a heterozygous nonsense variant of the NF1 gene. A 12-year-old boy was admitted because of short stature, numerous café-au-lait spots, low-set and posteriorly rotated ears, sparse eyebrows, broad forehead, and inverted triangular face. Cranial and spinal magnetic resonance imaging showed abnormal nodular lesions. Molecular analysis revealed a novel heterozygous c.6189 C > G (p.(Tyr2063*)) variant in the NF1 gene. The patient was not prescribed recombinant growth hormone (GH) therapy because exogenous GH may have enlarged the abnormal skeletal lesions. During follow-up, Lisch nodules were found in the ophthalmologic examination. NFNS, a variant form of NF1, is caused by heterozygous mutations in the NF1 gene. The mechanism of GH deficiency caused by NF1 is still unclear. Whether NFNS patients should be treated with exogenous GH remains controversial.

Schwannomatosis: a Realm Reborn: year one

PURPOSE OF REVIEW

In 2022, an international consensus recommendation revised the nomenclature for neurofibromatosis type 2 ( NF2 ) and Schwannomatosis (SWN), now grouped under the umbrella term Schwannomatosis, and defined new diagnostic criteria.

RECENT FINDINGS

This review describes the molecular criteria for diagnosis of schwannomatosis and the subsequent diagnosis strategy, while setting out the most recent advances in our understanding of the natural history, pathology, molecular biology and treatment of schwannomatosis-associated tumors, including schwannomas, meningiomas and ependymomas.

SUMMARY

Somatic mutation screening should become a new standard for the diagnosis of NF2 -, LTZTR1 -, SMARCB1 - and 22q-schwannomatosis to discriminate those conditions. Constitutional events in NF2 -Schwannomatosis have a major influence on disease severity and justifiably motivate ongoing efforts on gene replacement therapy research. On the other hand, underlying mechanisms of disease severity and associated pain remain largely unknown in non- NF2 -SWN and independent of germline mutation. Research efforts therefore focus on pain relief in ongoing trials and the discovery of new molecular mechanisms underlying schwannoma tumorigenesis/pain/neuropathies.

Neurofibromatosis- and schwannomatosis-associated tumors: Approaches to genetic testing and counseling considerations

Neurofibromatosis (NF) and schwannomatosis (SWN) are genetic conditions characterized by the risk of developing nervous system tumors. Recently revised diagnostic criteria include the addition of genetic testing to confirm a pathogenic variant, as well as to detect the presence of mosaicism. Therefore, the use and interpretation of both germline and tumor-based testing have increasing importance in the diagnostic approach, treatment decisions, and risk stratification of these conditions. This focused review discusses approaches to genetic testing of NF- and SWN-related tumor types, which are somewhat rare and perhaps lesser known to non-specialized clinicians. These include gastrointestinal stromal tumors, breast cancer, plexiform neurofibromas with or without transformation to malignant peripheral nerve sheath tumors, gliomas, and schwannomas, and emphasizes the need for inclusion of genetic providers in patient care and appropriate pre- and post-test education, genetic counseling, and focused evaluation by a medical geneticist or other healthcare provider familiar with clinical manifestations of these disorders.

Living with neurofibromatosis

Neurofibromatosis type 1 is a genetic disorder that has a number of cutaneous manifestations. Although these lesions typically do not require any form of intervention, it is important for clinicians to be sensitive to the impact that this condition can have on patients’ quality of life regardless. This viewpoint highlights the difficulties encountered by our patient as a result of this condition.

[New classification and approaches to the treatment of schwannomatosis]

Schwannomatoses is a new classification unit for all the hereditary diseases caused by chromosome 22 damage followed by multiple benign neoplasms of the peripheral and central nervous system. Schwannomatosis occurs as a result of damage to different genes: NF2, SMARCB1, LZRT1, loss of heterozygosity of the long arm of chromosome 22. Nevertheless, clinical manifestations are similar. Molecular diagnostics not only confirms the diagnosis, but also predicts the course of disease. Thus, the most severe clinical manifestations are observed in patients with violation of semantic sequences and reading frame shift in exons 2-13 of the NF2 gene. A more favorable course with less number of tumors is observed in patients with somatic mosaicism. Stereotactic irradiation and surgery are the main treatment options for schwannomatosis. However, there is evidence of effective targeted therapy with bevacizumab (inhibitor of vascular endothelial growth factor). Bevacizumab is used in patients with bilateral vestibular schwannomas and high risk of hearing loss, as well as for intramedullary tumor growth control.

Understanding barriers to diagnosis in a rare, genetic disease: Delays and errors in diagnosing schwannomatosis

Diagnosis of rare, genetic diseases is challenging, but conceptual frameworks of the diagnostic process can guide quality improvement initiatives. Using the National Academy of Medicine diagnostic framework, we assessed the extent of, and reasons for diagnostic delays and diagnostic errors in schwannomatosis, a neurogenetic syndrome characterized by nerve sheath tumors and chronic pain. We reviewed the medical records of 97 people with confirmed or probable schwannomatosis seen in two US tertiary care clinics. Time-to-event analysis revealed a median time from first symptom to diagnosis of 16.7 years (95% CI, 7.5-26.0 years) and median time from first medical consultation to diagnosis of 9.8 years (95% CI, 3.5-16.2 years). Factors associated with longer times to diagnosis included initial signs/symptoms that were intermittent, non-specific, or occurred at younger ages (p < 0.05). Thirty-six percent of patients were misdiagnosed; misdiagnoses were of underlying genetic condition (18.6%), pain etiology (16.5%), and nerve sheath tumor presence/pathology (11.3%) (non-mutually exclusive categories). One-fifth (19.6%) of patients had a clear missed opportunity for genetics workup that could have led to an earlier schwannomatosis diagnosis. These results suggest that interventions in clinician education, genetic testing availability, expert review of pathology findings, and automatic triggers for genetics referrals may improve diagnosis of schwannomatosis.

The Challenge of Diagnosing Constitutional Mismatch Repair Deficiency Syndrome in Brain Malignancies from Young Individuals

Biallelic germline mismatch repair (MMR) gene (MLH1, MSH2, MSH6, and PMS2) mutations are an extremely rare event that causes constitutional mismatch repair deficiency (CMMRD) syndrome. CMMRD is underdiagnosed and often debuts with pediatric malignant brain tumors. A high degree of clinical awareness of the CMMRD phenotype is needed to identify new cases. Immunohistochemical (IHC) assessment of MMR protein expression and analysis of microsatellite instability (MSI) are the first tools with which to initiate the study of this syndrome in solid malignancies. MMR IHC shows a hallmark pattern with absence of staining in both neoplastic and non-neoplastic cells for the biallelic mutated gene. However, MSI often fails in brain malignancies. The aim of this report is to draw attention to the peculiar IHC profile that characterizes CMMRD syndrome and to review the difficulties in reaching an accurate diagnosis by describing the case of two siblings with biallelic MSH6 germline mutations and brain tumors. Given the difficulties involved in early diagnosis of CMMRD we propose the use of the IHC of MMR proteins in all malignant brain tumors diagnosed in individuals younger than 25 years-old to facilitate the diagnosis of CMMRD and to select those neoplasms that will benefit from immunotherapy treatment.

Familial Nervous System Tumor Syndromes

PURPOSE OF REVIEW

Although sporadic primary neoplasms account for the majority of nervous system tumors, familial nervous system tumor syndromes are important and clinically relevant conditions for the neurologist to understand. This article reviews common inherited nervous system tumor syndromes including neurofibromatosis type 1, neurofibromatosis type 2, schwannomatosis, tuberous sclerosis complex, and von Hippel-Lindau syndrome. The epidemiology, genetics, approach to diagnosis, neurologic and nonneurologic manifestations, and management options are reviewed.

RECENT FINDINGS

Awareness of the more common and clinically relevant familial nervous system tumor syndromes is important. These conditions teach us about the underlying biology that drives tumor development in the central and peripheral nervous systems including peripheral nerve sheath tumors (eg, neurofibroma, schwannoma), meningioma, vestibular schwannoma, subependymal giant cell astrocytoma, and hemangioblastoma. Knowledge of the clinical manifestations ensures that the neurologist will be able to diagnose these conditions, recommend appropriate surveillance, refer to specialists, and support optimal management. Important discoveries in the role of the underlying genetics have contributed to the launch of several novel drug trials for these tumors, which are changing therapeutic options for patients.

SUMMARY

Familial nervous system tumor syndromes are uncommon conditions that require specialized surveillance and management strategies. Coordination across a multidisciplinary team that includes neurologists, neuro-oncologists, radiologists, neurosurgeons, radiation oncologists, otolaryngologists, pathologists, neuropsychologists, physical medicine and rehabilitation specialists, and geneticists is necessary for the optimal treatment of these patients.

Simultaneous Detection of NF1, SPRED1, LZTR1, and NF2 Gene Mutations by Targeted NGS in an Italian Cohort of Suspected NF1 Patients

Neurofibromatosis type 1 (NF1) displays overlapping phenotypes with other neurocutaneous diseases such as Legius Syndrome. Here, we present results obtained using a next generation sequencing (NGS) panel including NF1, NF2, SPRED1, SMARCB1, and LZTR1 genes on Ion Torrent. Together with NGS, the Multiplex Ligation-Dependent Probe Amplification Analysis (MLPA) method was performed to rule out large deletions/duplications in NF1 gene; we validated the MLPA/NGS approach using Sanger sequencing on DNA or RNA of both positive and negative samples. In our cohort, a pathogenic variant was found in 175 patients; the pathogenic variant was observed in NF1 gene in 168 cases. A SPRED1 pathogenic variant was also found in one child and in a one year old boy, both NF2 and LZTR1 pathogenic variants were observed; in addition, we identified five LZTR1 pathogenic variants in three children and two adults. Six NF1 pathogenic variants, that the NGS analysis failed to identify, were detected on RNA by Sanger. NGS allows the identification of novel mutations in five genes in the same sequencing run, permitting unambiguous recognition of disorders with overlapping phenotypes with NF1 and facilitating genetic counseling and a personalized follow-up.

NF1 microdeletion syndrome: a phenotypical characterization of a rare case of neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is one of the most common neurocutaneous disorders, resulting from a wide spectrum of mutations in the NF1 gene. The NF1 microdeletion syndrome is characterized by a more severe clinical presentation than the majority of NF1 patients, with facial dysmorphic features, cognitive impairment, developmental delay, early-onset neurofibromas, and an increased risk of malignant tumors. This report provides the phenotypical characterization of a young boy diagnosed with this syndrome.

The Diagnosis and Management of Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1), NF2, and schwannomatosis are related, but distinct, tumor suppressor syndromes characterized by a predilection for tumors in the central and peripheral nervous systems. NF1 is one of the most common autosomal dominant conditions of the nervous system. NF1 has a high degree of variability in clinical presentation, which may include multiple neoplasms as well as cutaneous, vascular, bony, and cognitive features. Some of these manifestations overlap with other genetic conditions. Accurate diagnosis of NF1 is important for individualizing clinical care and genetic counseling. This article summarizes the clinical features, diagnostic work-up, and management of NF1.

Coexistence of schwannomatosis and glioblastoma in two families

Schwannomatosis is a rare affection predisposing to multiple peripheral neurologic tumors development. Approximatively, one third of patients with schwannomatosis are carriers of a germline mutation in LZTR1 (Leucin Zipper Transcription Regulator 1). Tumorigenesis in schwannomatosis responds to a somatic 5-hit/3-step mechanism resulting in a loss of function (LOF) of LZTR1 and the contiguous genes of locus 22q11.2q12.2. Effectively, LZTR1 is mapped on 22q11.2 and centromeric to SMARCB1 also implicated in the determinism of schwannomatosis and NF2, responsible for neurofibromatosis type 2. On a somatic point of view, LZTR1 mutations are known to drive with a significant frequency glioblastoma (GB) development. We report here two families in which segregate both multiple schwannomas and GB. In the first family, the proband received a diagnosis with of schwannomatosis after a surgery for a lumbar schwannoma at age 43, molecularly confirmed by identification of a germline heterozygous mutation in LZTR1. Her father, having unremarkable medical history deceased from an apparently isolated GB at age 59. In the second family, LZTR1-related schwannomatosis was diagnosed in the index case at age 70 after multiple schwannomas surgeries. Her elder sister had no neurological medical history before occurrence of a lethal GB at age 78. Molecular analysis of GB sample from both affected relatives showed the presence of the familial mutation. These observations hypothesize a potential link between schwannomatosis and the GB development.

Long QT syndrome KCNH2 mutation with sequential fetal and maternal sudden death

We report a case of a woman who experienced intrauterine fetal death at full term pregnancy, and then died suddenly soon after learning about the death of her fetus. At autopsy, previously undiagnosed neurofibromatosis and an adrenal gland pheochromocytoma were discovered in the mother. Genetic screening also revealed a novel KCNH2mutation in both fetus and mother indicating type 2 congenital long-QT syndrome (LQTS). A catecholamine surge was suspected as the precipitating event of fetal cardiac arrhythmia and sudden fetal death, while the addition of emotional stress provoked a lethal cardiac event in the mother. This case illustrates the potential for lethal interactions between two occult diseases (pheochromocytoma, LQTS).

Isolated bladder schwannoma: a rare presentation

Bladder schwannoma is a rare tumour arising from Schwann cells in nerve sheaths. It is usually more common in patients diagnosed with neurofibromatosis. However, isolated cases of urinary bladder schwannoma is incredibly rare, attributing to <0.1% of bladder tumours. A literature review and analysis revealed that it presents in adulthood, is mostly symptomatic and diagnosis is established histologically. We report a case of isolated bladder schwannoma in 25 year-old female who presented with dyspareunia.

Segmental distribution of nodules on trunk

A 70-year-old Caucasian man presented with a longstanding history of numerous nontender, fleshy, skin-colored papules on his trunk, ranging from 3 to 8 mm in size. They were noted incidentally during an examination of unrelated nonhealing lesions on the patient's left cheek. He said the lesions on his trunk first appeared when he was 28 years old and had continued to grow in size and number. The patient said his son had at least one similar lesion on his upper back, but otherwise there was no family history of these lesions. A biopsy was performed on one of the nodules. WHAT IS YOUR DIAGNOSIS? HOW WOULD YOU TREAT THIS PATIENT?

[Overlap syndrome. LEOPARD and neurofibromatosis. A case report]

We expose a clinical case of a 43-year-old patient who was attended at the Dermatology service in a general hospital of the Instituto Mexicano del Seguro Social, with a disseminated pattern of lentigines, psychomotor retardation and electrocardiographic abnormalities. Afterwards, we made an analysis of the literature.

Genomic findings in patients with clinical suspicion of 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome, one of the most common human genomic syndromes, has highly heterogeneous clinical presentation. Patients usually harbor a 1.5 to 3 Mb hemizygous deletion at chromosome 22q11.2, resulting in pathognomic TBX1, CRKL and/or MAPK1 haploinsufficiency. However, there are some individuals with clinical features resembling the syndrome who are eventually diagnosed with genomic disorders affecting other chromosomal regions. The objective of this study was to evaluate the additive value of high-resolution array-CGH testing in the cohort of 41 patients with clinical features of 22q11.2 deletion syndrome and negative results of standard cytogenetic diagnostic testing (karyotype and FISH for 22q11.2 locus). Array-CGH analysis revealed no aberrations at chromosomes 22 or 10 allegedly related to the syndrome. Five (12.2 %) patients were found to have other genomic imbalances, namely 17q21.31 microdeletion syndrome (MIM#610443), 1p36 deletion syndrome (MIM#607872), NF1 microduplication syndrome (MIM#613675), chromosome 6pter-p24 deletion syndrome (MIM#612582) and a novel interstitial deletion at 3q26.31 of 0.65 Mb encompassing a dosage-dependent gene NAALADL2. Our study demonstrates that the implementation of array-CGH into the panel of classic diagnostic procedures adds significantly to their efficacy. It allows for detection of constitutional genomic imbalances in 12 % of subjects with negative result of karyotype and FISH targeted for 22q11.2 region. Moreover, if used as first-tier genetic test, the method would provide immediate diagnosis in ∼40 % phenotypic 22q11.2 deletion subjects.

Ruptured Popliteal Aneurysm Resulting from Neurofibromatosis

Rupture of an aneurysm in a patient suffering from neurofibromatosis is a rare though documented complication. Presented here is the case of a 33-year-old woman with known neurofibromatosis who underwent repair of a symptomatic popliteal aneurysm. The presentation, diagnostic evaluation, and treatment are discussed, and the literature is reviewed on this rare entity.

Management of multiple tumors in neurofibromatosis type 2 patients

INTRODUCTION

Neurofibromatosis type 2 is characterized by the presence of bilateral vestibular schwannomas. However, other nervous system tumors may also occur. Therefore, the management of NF2 patients is complex and requires a multidisciplinary discussion in a specialized center.

MATERIALS AND METHODS

All recent articles concerning tumors other than vestibular schwannoma in NF2 disease were reviewed, using PubMed databases.

RESULTS

Intracranial meningiomas occur in 50% of NF2 patients, and are often multiple. Surgery remains the main treatment and should be performed in cases of growing tumors. The role of antiangiogenic therapy is currently under evaluation and the role of radiosurgery still remains to be defined in NF2 disease. Spinal tumors occur in about half of NF2 patients. Surgery should be discussed when radiological tumor progression is demonstrated, even if spinal tumors are asymptomatic, in order to preserve neurological function and good quality of life. As regards lower cranial nerve schwannomas, radiosurgery appears to be a more appropriate treatment for growing tumor with a small volume in order to avoid post-operative complications, especially swallowing disorders. Facial nerve schwannomas may appear, on MRI, like vestibular schwannomas. The diagnosis should be suspected when the facial palsy is an early symptom during cerebello-pontine tumor progression. Trigeminal schwannomas are frequent in NF2 disease and fortunately they are often asymptomatic. Among major neurofibromatosis types, peripheral nerve sheath schwannomas are only present in patients with NF2 disease and schwannomatosis. Surgical resection is required when the cutaneous schwannomas is painful or when tumor progression is observed and causes symptoms.

CONCLUSION

Tumors other than vestibular schwannoma are also associated with a poor prognosis in NF2 patients. Surgery remains the main treatment in most cases. Each treatment decision in NF2 disease requires a complete evaluation of all cranial and spinal locations of the disease in order to establish surgical priorities and strategies.

The natural history of spinal neurofibromatosis: a critical review of clinical and genetic features

Spinal neurofibromatosis (SNF) is a related form of neurofibromatosis 1 (NF1), characterized by bilateral neurofibromas (histologically proven) of all spinal roots (and, eventually, of all the major peripheral nerve branches) with or without other manifestations of classical NF1. By rigorous application of these criteria to the 98 SNF cases published, we developed: (i) a cohort of 49 SNF patients (21 males and 28 females; aged 4-74 years]: 9 SNF families (21/49), 1 mixed SNF/NF1 family (1/49) and 27 of 49 sporadic SNF patients (including 5 unpublished patients in this report); and (ii) a group of 49 non-SNF patients including: (a) 32 patients with neurofibromas of multiple but not all spinal roots (MNFSR): 4 mixed SNF/MNFSR families (6/32); (b) 14 patients with NF1 manifestations without spinal neurofibromas, belonging to SNF (8/49) or MNFSR families (6/32); (c) 3 patients with neurofibromas in one spinal root. In addition to reduced incidence of café-au-lait spots (67% in SNF vs 56% in MNFSR), other NF1 manifestations were less frequent in either cohort. Molecular testing showed common NF1 gene abnormalities in both groups. The risk of developing SNF vs NF1 was increased for missense mutations [p = 0.0001; odds ratio (OR) = 6.16; confidence interval (CI) = 3.14-13.11], which were more frequent in SNF vs MNFSR (p = 0.0271).

Breast cancer and neurofibromatosis type 1: a diagnostic challenge in patients with a high number of neurofibromas

BACKGROUND

Neurofibromatosis 1 is one of the most common genetic diseases in humans, presenting with multiple neurofibromas and an increased risk of various benign and malignant tumors, including breast cancer.

CASE PRESENTATION

In this paper we report a case of a woman with neurofibromatosis 1 and the challenge associated with detecting an advanced breast cancer because of numerous skin neurofibromas, which were responsible for a substantial delay in cancer diagnosis. Literature concerning the association of neurofibromatosis 1 and breast cancer is reviewed and discussed.

CONCLUSIONS

Best practice guidelines for breast cancer detection are not sufficient for the screening of neurofibromatosis 1 carriers. A more intensive clinical and imaging approach should be used if the same early detection rate as in non-neurofibromatosis 1 women is to be achieved.

Images in clinical medicine: Segmental neurofibromatosis

A 4-year-old girl presented for evaluation of cutaneous nodules that had been present on the left side of her trunk since birth. Physical examination revealed numerous soft, nontender papules and nodules across the left upper abdomen and wrapping around to the back.

A rare case of segmental neurofibromatosis with multiple blue-red pseudoatrophic plaques

We report the case of a 5-year-old girl who presented with 2 blue-red atrophic plaques on the left leg as well as subcutaneous nodules that were present since infancy. Although the clinical criteria of neurofibromatosis (NF) were absent, microscopic examination revealed features of a blue-red neurofibroma.

Sclerosing Segmental Neurofibromatosis

Segmental neurofibromatosis is a rare disorder characterized by cafe-au-lait macules and/or neurofibromas limited to a single body segment. The neurofibromas in segmental neurofibromatosis are usually soft, non-tender nodules as in other types of neurofibromatosis. Histopathologically, they are usually non-encapsulated, loosely textured dermal tumors. We report a case of sclerosing segmental neurofibromatosis, in which the patient presented with several grouped, erythematous to brownish, firm tender nodules on the left side of the posterior neck. Histopathologically, the stroma was mostly very fibrotic, especially around hair follicles, in addition to the usual features of neurofibroma. The atypical clinical feature, hardness, and tenderness of the lesions may be associated with the fibrosis.

Intraneural perineurioma affecting multiple nerves: a case report and literature review

Intraneural perineurioma is a neoplasm of perineurial cells, corresponding to WHO grade I. We present a case of intraneural perineurioma affecting multiple nerves, which usually involved one or two of major nerve trunks in one patient. We describe the clinical presentation, magnetic resonance (MR) neurography characteristics, and pathological characteristics. The differential diagnosis with other diseases, such as neurofibroma, Schwannomatosis and HNPP, will also be discussed. We also review the literature in efforts to highlight recent studies on intraneural perineurioma and heighten and awareness for the possible presentations of this disorder.

A case of late-onset segmental neurofibromatosis

Segmental neurofibromatosis (NF5) is a rare variant of neurofibromatosis. To our knowledge, there have been few reports of cases presenting later in life. The recognition of NF5 is important, as there have been reports of paraneoplastic manifestations and transmission to offspring. Here we present the case of a patient who presented with NF5 first appearing in her mid-50s. This case illustrates the subtle nature of NF5, which often leads to misdiagnosis.

[How to recognize neurofibromatosis?]

Neurofibromatosis 1 is a hereditary symptom predisposing to cancer, affecting some 1,500 Finnish people. This systemic disease is most commonly detected through cutaneous findings. Although the cutaneous symptoms are harmless, they impair the patients' quality of life. The disease is, however, insidious, as the complications often become manifested from unexpected organ systems. For example cancers originally from nervous systems and severe bone lesions require rapid diagnosis and treatment. The healthcare personnel should thus be aware of the diagnosis of NF syndrome, and the patients should have sufficient knowledge of their disease.

[Segmental schwannomatosis in upper-extremity: 5 cases report and literature review]

OBJECTIVE

Multiple schwannomas localized in a single body part not crossing the midline constitute a rare variant of neurofibromatosis, segmental schwannomatosis. We report our experience with 5 cases of segmental schwannomatosis of the upper extremity and review the related literature to improve our skills in diagnosis and differentiation.

METHODS

Five patients with segmental schwannomatosis received surgical treatment in our department from 2003 to 2012, of whom 4 were female and the other one male. The mean age was 38 years, ranging from 29 to 48 years. In retrospect, we discussed the clinical appearance, histologic characteristics, genetic data and surgical management.

RESULTS

A total of 351 patients with schwannomas were treated in the recent decade. There were 326 patients with solitary schwannoma, accounting for 92.88%, 25 with neurofibromatosis type 2 (NF-2), occupying 7.12% and 5 with segmental schwannomatosis representing 1.42% of the total. Schwannomas are limited in one upper extremity and randomly located at ulnar nerve, median nerve and radial nerve and their branches, with no obvious predisposition. Their family history was negative for cutaneous tumors or central nervous system disease. Neurological examinations did not reveal symptoms related to vestibular nerves or optic nerves, which excluded NF-2 preliminarily. The prior symptom of three cases was pain which could be irradiated to the nerve distribution area. No pain but slight numbness was found in two cases. MRI disclosed multiple masses along the course of the nerves. They were isointense to muscle on T1-weighed images and hyperintense to subcutaneous fat on T2-weighed images. All schwannomas were resected and histological sections exhibited a characteristic feature of schwannoma. Follow-up work of 4.5 years was done to 4 cases and no recurrence or impairment of nerves was found.

CONCLUSION

Segmental schwannomatosis is characterized by multiple schwannomas localized in one limb (upper extremity in our cases) without vestibular nerve tumors, most frequently seen in females at the age of 30-60 years. Segmental schwannomatosis is rarely seen in the previous literature. We found around 20 cases in English articles and no cases in domestic articles. In consideration of the clinical appearances of these 5 cases and the genetic research in the related literature, we recommend that segmental schwannomatosis is a distinct form of neurofibromatosis which needs to be more studied. We should also pay more attention to differentiating this disease from other forms of neurofibromatosis.

Intrabronchial neurofibromatosis

Thoracic manifestations of Neurofibromatosis include intrathoracic posterior mediastinal tumours, meningocoeles, kyphoscoliosis and interstitial fibrosis. Even though mediastinal neurofibromas are common, intrapulmonary neurofibromas are very rare. In this paper, we present a case of intrathoracic neurofibroma with intrabronchial extension. Lesions extending into the bronchial lumen making bronchoscopic diagnosis possible, as in this case is extremely rare. The case is presented because of its rarity.

Multiple neurofibromas as the presenting feature of familial atypical multiple malignant melanoma (FAMMM) syndrome

Mutations in the cyclin-dependent kinase inhibitor-2A (CDKN2A) gene have been associated with a number of malignancies, most notably cutaneous malignant melanoma (CMM). Mutations in this gene have also been associated with pancreatic cancer and breast cancer, as well as astrocytomas and other nervous system tumors (NST). Among NST, rare solitary internal neurofibromas have been reported, but multiple cutaneous neurofibromas have only been described in two families. In the first family, the affected individuals all carried a heterozygous G>C mutation at the splice acceptor site of intron 1 resulting in skipping of CDKN2A exon 2, while the affected individuals in the second family had a deletion that encompassed the whole CDKN2A/CDKN2B/ANRIL locus. We now report on a proposita presenting with multiple biopsy-proven cutaneous neurofibromas and a solitary spinal neurofibroma found to have a deletion of 14 nucleotides in exon 2 of CDKN2A, providing further evidence that p14, p16, and/or ANRIL are specifically involved in the pathogenesis of neurofibromas as a feature of the familial atypical multiple malignant melanoma spectrum.

Diagnosis and treatment of osteopenic fractures in children

Osteopenic fractures occur in children every day. At times the osteopenic nature of these fractures is painfully obvious, as in neurofibromatosis and osteogenesis imperfecta, while in many other situations overt osteopenia does not declare itself, such as in normal and obese children. Normal pediatric bone growth commonly involves periods of relative bone weakness. Childhood obesity creates a situation where bone is unable to fully adapt to the stresses placed upon it. Conditions like neurofibromatosis and osteogenesis imperfecta place pediatric bone at a distinct genetic disadvantage. This review will highlight recent research in these areas and provide radiographic examples of the treatment of osteopenic fractures in children.

Painless cutaneous nodules

The lesions on the patient's body were getting caught on his clothes. He said that his mother and several of his siblings had similar "lumps".

Multiple or familial café-au-lait spots is neurofibromatosis type 6: clarification of a diagnosis

A café-au-lait macule (CALM) is an evenly pigmented macule or patch of variable size. Solitary CALMs are common birthmarks in up to 2.5 percent of normal neonates and their incidence rises to up to 25 percent in preschool-aged children. Two or more CALMs occur much less frequently. Multiple lesions may warrant investigation to identify an underlying disease including neurofibromatosis types 1 (NF1), neurofibromatosis type 2, McCune-Albright syndrome, and neurofibromatosis type 1-like syndrome. Considered a hallmark and diagnostic criteria for NF1 is the presence of 6 or more CALMs greater than 0.5 cm in prepubertal individuals. Rare reports describe families which demonstrate the phenomenon of multiple CALMs without other stigmata of NF1 or evidence of other systemic disease. Herein is a description of the condition and justification for this entity to be named Neurofibromatosis type 6.

Quantitative assessment of whole-body tumor burden in adult patients with neurofibromatosis

PURPOSE

Patients with neurofibromatosis 1 (NF1), NF2, and schwannomatosis are at risk for multiple nerve sheath tumors and premature mortality. Traditional magnetic resonance imaging (MRI) has limited ability to assess disease burden accurately. The aim of this study was to establish an international cohort of patients with quantified whole-body internal tumor burden and to correlate tumor burden with clinical features of disease.

METHODS

We determined the number, volume, and distribution of internal nerve sheath tumors in patients using whole-body MRI (WBMRI) and three-dimensional computerized volumetry. We quantified the distribution of tumor volume across body regions and used unsupervised cluster analysis to group patients based on tumor distribution. We correlated the presence and volume of internal tumors with disease-related and demographic factors.

RESULTS

WBMRI identified 1286 tumors in 145/247 patients (59%). Schwannomatosis patients had the highest prevalence of tumors (P = 0.03), but NF1 patients had the highest median tumor volume (P = 0.02). Tumor volume was unevenly distributed across body regions with overrepresentation of the head/neck and pelvis. Risk factors for internal nerve sheath tumors included decreasing numbers of café-au-lait macules in NF1 patients (P = 0.003) and history of skeletal abnormalities in NF2 patients (P = 0.09). Risk factors for higher tumor volume included female gender (P = 0.05) and increasing subcutaneous neurofibromas (P = 0.03) in NF1 patients, absence of cutaneous schwannomas in NF2 patients (P = 0.06), and increasing age in schwannomatosis patients (p = 0.10).

CONCLUSION

WBMRI provides a comprehensive phenotype of neurofibromatosis patients, identifies distinct anatomic subgroups, and provides the basis for investigating molecular biomarkers that correlate with unique disease manifestations.

Neurofibromatoses

The studies of familial tumor predisposition syndromes have contributed immensely to our understanding of oncogenesis. Neurofibromatosis 1, neurofibromatosis 2 and schwannomatosis are inherited autosomal dominant neurocutaneous disorders with complete penetrance. They are clinically and genetically distinct and considerable knowledge has been gathered about their pathogenesis. In this chapter, the genetics, molecular mechanism of disease, as well as clinical features, diagnosis and treatment are discussed.

[Esthetic otoplasty in subjects presenting with facial neurofibromatosis]

The results of surgical treatment of a woman presenting with facial and cervical soft-tissue neurofibromatosis and a concomitant auricular defect are presented. The otoplasty was performed by means of sectoral dissection of the auricular skeleton as described by Trendelenburg with the subsequent correction of the surrounding facial and cervical tissues. Much attention is given to the step by step procedure of correction of the auricular deformity and the surrounding facial and cervical tissues in the patients with this pathology.

Uncertainty management and communication preferences related to genetic relativism among families affected by down syndrome, Marfan syndrome, and neurofibromatosis

Genes hold opportunities for us to look backward and forward in family health and disease incidence. Our beliefs about genes' roles in health form around frameworks relating to personal control, and the influence of social networks and/or religious faith on genetic expression in health. These genetic relativistic frameworks were found to predict levels of illness uncertainty among 541 diagnosed adults and family members affected by neurofibromatosis, Down syndrome, and Marfan syndrome. Participants were recruited and surveyed about their expectations and preferences for communicating about their respective disorder, with illness uncertainty found to predict the desire to communicate about the condition and to manage related uncertainty. The desire to manage uncertainty in ways that foster control and hope partially mediated the relationship between illness uncertainty and communication preferences. Negative feelings about the condition, which were stronger for affected participants than for family members, related to illness uncertainty, the desire to manage uncertainty, and communication preferences, mediating the relationship between illness uncertainty and uncertainty management. Findings contribute to research in illness uncertainty management and have pragmatic implications for the design of counseling and educational materials associated with the genetic conditions considered in this research.