High prevalence of elevated blood pressure among children with neurofibromatosis type 1

Feasibility of home blood pressure screening in the paediatric outpatient clinic setting

OBJECTIVE

The aim of this study was to evaluate the acceptability and feasibility of home-based blood pressure (BP) screening in a group of paediatric patients with known elevated risk of developing hypertension.

DESIGN

Cross-sectional study.

SETTING

Specialist outpatient clinic and patient homes.

PATIENTS

52 children and adolescents living with neurofibromatosis type 1.

INTERVENTIONS

Clinic BP measured thrice manually and once via an automated device; home BP measured daily with the same device for 3 days.

MAIN OUTCOME MEASURES

Acceptability and feasibility were assessed with a Children's Anxiety Meter-State score, the comparability of home and clinic BPs, a parental survey, assessment of costs and the device return rate.

RESULTS

Home systolic BP and diastolic BP were statistically similar to both clinic manual (95% CI -4.78 to 0.13; -4.80 to 0.93) and automatic BPs (95% CI -4.44 to 2.08; -0.54 to 5.52). Anxiety scores (95% CI -0.57 to 0.35) were also similar between settings. Participants and their families reported that home BP measurement was easy, took ~10 min and minimally interrupted family life. Families also largely preferred home BP screening (73% 'yes', 23% 'not sure', 3% 'no'), and 90% returned their devices. Families reported substantial costs in attending clinic, which could be reduced with access to this home BP programme.

CONCLUSIONS

Home BP screening was acceptable and feasible, with home BPs comparable to clinic measurements, no associated anxiety and preferred by families. Telehealth with home BP screening is a viable alternative to in-person appointments, which could reduce individual costs, and foster greater equity of care and access to health services.

Genotypes and phenotypes of neurofibromatosis type 1 patients in Japan: A Hereditary Tumor Cohort Study

Neurofibromatosis type 1 (NF1) presents with a broad spectrum of clinical manifestations, including an increased risk of tumor development and hypertension. Comprehensive data on genotype‒phenotype correlations in patients with NF1 are limited. Therefore, in this study, we aimed to elucidate the detailed genetic and clinical characteristics of NF1 in a hereditary tumor cohort. We performed sequencing and copy number assays in a clinical laboratory and analyzed the clinical data of 44 patients with suspected NF1. Germline pathogenic variants were detected in 36 patients (81.8%), and 20.7% of the variants were novel. Notably, 40.0% of adult patients presented with malignancies; female breast cancer occurred in 20.0% of patients, which was a higher rate than that previously reported. Hypertension was observed in 30.6% of the adult patients, with one patient experiencing sudden death and another developing pheochromocytoma. Three patients with large deletions in NF1 exhibited prominent cutaneous, skeletal, and neurological manifestations. These results highlight the importance of regular surveillance, particularly for patients with malignancies and hypertension. Our findings provide valuable insights for genetic counseling and clinical management, highlighting the multiple health risks associated with NF1 and the need for comprehensive and multidisciplinary care.

Quantitative OCT angiography of the retinal and choroidal vascular circulation in pediatric patients with neurofibromatosis type 1

PURPOSE

To investigate retinal and choroidal microvascular changes in neurofibromatosis type 1 (NF1) pediatric patients using optical coherence tomography angiography (OCTA).

METHODS

This study was performed on 21 eyes of 21 NF1 patients and 30 eyes of 30 healthy subjects. Foveal avascular zone (FAZ) parameters, including area, perimeter, acircularity index, and foveal density, were measured using OCTA. Superficial (SCP) and deep (DCP) capillary plexus and radial peripapillary capillary (RPC) vessel densities and choriocapillaris flow were also evaluated. Choroidal nodules and thickness were detected using infrared reflectance and enhanced-depth imaging OCT.

RESULTS

No significant differences were observed for FAZ parameters or SCP and RPC vessel densities between groups. DCP vessel densities in the perifovea were significantly lower in the NF1 group than in the control group (P = 0.001). A significantly lower choriocapillaris flow area (P < 0.001) and increased subfoveal and nasal perifoveal choroidal thickness (P < 0.001) were observed in the NF1 group. Choriocapillaris flow area tended to be inversely related to the number of choroidal nodules in the NF1 group.

CONCLUSIONS

Perifoveal DCP vessel density and choriocapillaris flow significantly differed between NF1 patients and controls, suggesting that retinal and choroidal vascular microcirculation is affected in the former, potentially by choroidal nodules. Further longitudinal studies are required to determine the effects of these differences on circulation in the posterior segment of the eye.

Renal manifestations in children with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal-dominant neurocutaneous syndrome affecting various parts of the body, including the renovascular and urinary systems. We evaluated the renovascular, urinary, glomerular, and tubular functions of children with NF1. We compared blood pressures, urinary findings, and renal glomerular and tubular functions in children with NF1 with those of a healthy age- and gender-matched control group. We evaluated 46 NF1 patients and 33 healthy controls. The mean ages of the NF1 group (female/male: 20/26) and the control group (female/male: 15/18) were 10.1 ± 4.6 and 10.6 ± 4.3 years respectively. Six NF1 patients were hypertensive. The mean blood pressures of the NF1 group were significantly higher than those of the control group. Renal artery stenosis was detected in one NF1 patient. Urinary tract anomalies were evident in 21.7% of NF1 but only 9% of control subjects. The mean estimated glomerular filtration rate (eGFR) of the NF1 group was significantly lower than that of the control group. Six NF1 patients evidenced eGFRs < 90 mL/min. In the NF1 group, tubular phosphorus reabsorption was significantly lower and uric acid excretion significantly higher than in the control group.Conclusion: Hypertension, urinary tract anomalies, and impaired renal function were more common in NF1 patients than healthy controls. Regular blood pressure measurements and evaluation of urinary tract and kidney function are essential for NF1 patients. What is Known: • NF1 is most commonly associated with systemic hypertension due to renal artery vasculopathy and the development of a pheochromocytoma. • Hydronephrosis and bladder involvement have been documented in NF1. What is New: • Renal glomerular and tubular functions may be affected in NF1.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Identification of NF1 Frameshift Variants in Two Chinese Families With Neurofibromatosis Type 1 and Early-Onset Hypertension

Background: Neurofibromatosis type 1 (NF-1) is a common autosomal dominant disorder caused by mutations in the NF1 gene. It is characterized by multiple café-au-lait macules, cutaneous neurofibromas, optic glioma, Lisch nodules, and axillary and inguinal freckling. The aim of this study was to investigate NF1 mutations in two Chinese families with NF-1 who presented with early-onset hypertension, and to determine the prevalence of hypertension associated with NF-1 to better understand this complication. Methods: Whole-exome sequencing was performed for the probands with NF-1 from two unrelated families. Possible pathogenic mutation was predicted by bioinformatic tools. Sanger sequencing was used to confirm candidate variants in all available individuals for familial co-segregation analysis. We also performed a systematic literature review of studies that reported the prevalence of hypertension in patients with NF-1. Results: In family 1, a recurrent mutation c.6789_6792delTTAC in NF1 was identified in the proband but in no other family members, indicating that this is a de novo mutation. In family 2, a novel mutation c.6934_6936delGCAinsTGCT in NF1 was detected in the proband and two other family members, which co-segregated with the disease phenotype within the family. Both mutations were predicted to be pathogenic by bioinformatic analysis. We found hypertension was a relatively common complication of NF-1, with a prevalence range of 6.1-23.4%. Ambulatory blood pressure monitoring is a stable method for detecting initial alterations of the blood pressure pattern, particularly for pre-hypertension. Conclusions: We identified one recurrent (c.6789_6792delTTAC) and one novel frame-shift mutation (c.6934_6936delGCAinsTGCT) in two unrelated families with NF-1 using whole-exome sequencing. In consideration of phenotypic heterogeneity in NF-1, genetic testing is a robust tool which helps early and accurate diagnosis. Because hypertension is not a rare complication of NF-1, routine screening for hypertension in patients with NF-1, especially children and adolescents, is important to avoid serious cardiovascular events.

Ask-Upmark kidney in a girl with neurofibromatosis type 1

Ask-Upmark kidney (AUK) is a scarred segment of the kidney, characterized by formation of primitive tubular and glomerular structures, and sporadically diagnosed as a cause of hypertension (HTN). A 6-year-old girl with neurofibromatosis type 1 (NF1) and moyamoya syndrome had severe HTN. Based on past history, she had HTN at the age of 1.5 years. Laboratory examination revealed slightly elevated plasma and renal venous renin activity without lateralization. No evidence of pheochromocytoma, or coarctation of the aorta was found. Contrast-enhanced computed tomography (CT) showed an area of hypoperfusion in the upper and middle poles with reduced size of the right kidney. The results of dimercaptosuccinic acid scintigraphy were in accordance with those of contrast-enhanced CT. Selected renal arteriography revealed a paucity of peripheral vascularity in the same parts of the right kidney. In the absence of a history of urinary tract infection and vesicoureteral reflux by cystography, we presumed that the severe HTN may be due to segmental hypoplasia of the kidney, AUK, with a possible contribution from NF1. Although renal artery stenosis and pheochromocytoma are well-known causes of HTN in NF1, this case demonstrates that HTN can be caused by AUK in patients with NF1.

New guidelines for the diagnosis, evaluation, and treatment of pediatric hypertension

Childhood hypertension has become a significant public health problem due to increased prevalence in recent decades. High blood pressure causes increased mortality and morbidity in childhood, precedes adult hypertension, and causes increased cardiovascular events in adulthood. These concerns have led to an update of guidelines about childhood hypertension by the European Society of Hypertension in 2016 and the American Academy of Hypertension in 2017. This review highlights the important developments in these guidelines and recent literature about childhood hypertension in terms of diagnosis, prevalence, risk factors, diagnostic tools, prevention and management.

Current status and recommendations for imaging in neurofibromatosis type 1, neurofibromatosis type 2, and schwannomatosis

Neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis (SWN) are three clinically distinct tumor predisposition syndromes with a shared tendency to develop peripheral and central nervous system neoplasms. Disease expression and complications of NF1, NF2, and SWN are highly variable, necessitating a multidisciplinary approach to care in order to optimize outcomes. This review will discuss the imaging appearance of NF1, NF2, and SWN and highlight the important role that imaging plays in informing management decisions in people with tumors associated with these syndromes. Recent technological advances, including the role of both whole-body and localized imaging strategies, routine anatomic and advanced magnetic resonance (MR) imaging sequences such as diffusion-weighted imaging (DWI) with quantitative apparent diffusion coefficient (ADC) mapping, and metabolic imaging techniques (MR spectroscopy and positron emission testing) are discussed in the context of the diagnosis and management of people with NF1, NF2, and SWN based on the most up-to-date clinical imaging studies.

Bilateral pheochromocytoma and a tumor of the jejunum with neurofibromatosis of type 1

Neurofibromatosis type 1 (NF1) is a hereditary disease with the high frequency of neuroendocrine tumors. This article represents a clinical case of the diagnosed NF1 in a 40-year old patient with the history of bilateral pheocromocytoma and malignant gastrointestinal stromal tumor of the jejunum. Clinical diagnosis NF1 was suspected on the basis of the typical skin manifestations.The timely diagnosis of NF1 has practical significance as it enables physicians persistently search for neuroendocrine lesions in a such cohort of patients.

Health Supervision for Children With Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is a multisystem disorder that primarily involves the skin and peripheral nervous system. Its population prevalence is approximately 1 in 3000. The condition is usually recognized in early childhood, when pigmentary manifestations emerge. Although NF1 is associated with marked clinical variability, most children affected follow patterns of growth and development within the normal range. Some features of NF1 can be present at birth, but most manifestations emerge with age, necessitating periodic monitoring to address ongoing health and developmental needs and minimize the risk of serious medical complications. In this report, we provide a review of the clinical criteria needed to establish a diagnosis, the inheritance pattern of NF1, its major clinical and developmental manifestations, and guidelines for monitoring and providing intervention to maximize the health and quality of life of a child affected.

Arterial Stiffness in a Toddler with Neurofibromatosis Type 1 and Refractory Hypertension

Arterial hypertension is a common finding in patients with neurofibromatosis (NF) type 1. Renovascular hypertension due to renal artery stenosis or midaortic syndrome could be the underlying cause. We report the case of a 4-year-old girl with NF type 1 and midaortic syndrome whose changes in blood pressure and pulse wave velocity suggested the evolution of vasculopathy, diagnosis of renovascular hypertension, and provided insights of response to treatment. Hypertension persisted after percutaneous transluminal angioplasty in the abdominal aorta, requiring escalation of antihypertensive treatment, while arterial stiffness demonstrated a mild decrease. Regular assessment of blood pressure using ambulatory blood pressure monitoring and noninvasive assessment of arterial stiffness may enhance the medical care of patients with NF type 1.

Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents

These pediatric hypertension guidelines are an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents." Significant changes in these guidelines include (1) the replacement of the term "prehypertension" with the term "elevated blood pressure," (2) new normative pediatric blood pressure (BP) tables based on normal-weight children, (3) a simplified screening table for identifying BPs needing further evaluation, (4) a simplified BP classification in adolescents ≥13 years of age that aligns with the forthcoming American Heart Association and American College of Cardiology adult BP guidelines, (5) a more limited recommendation to perform screening BP measurements only at preventive care visits, (6) streamlined recommendations on the initial evaluation and management of abnormal BPs, (7) an expanded role for ambulatory BP monitoring in the diagnosis and management of pediatric hypertension, and (8) revised recommendations on when to perform echocardiography in the evaluation of newly diagnosed hypertensive pediatric patients (generally only before medication initiation), along with a revised definition of left ventricular hypertrophy. These guidelines include 30 Key Action Statements and 27 additional recommendations derived from a comprehensive review of almost 15 000 published articles between January 2004 and July 2016. Each Key Action Statement includes level of evidence, benefit-harm relationship, and strength of recommendation. This clinical practice guideline, endorsed by the American Heart Association, is intended to foster a patient- and family-centered approach to care, reduce unnecessary and costly medical interventions, improve patient diagnoses and outcomes, support implementation, and provide direction for future research.

Neurofibromatosis type 1 is not associated with subarachnoid haemorrhage

BACKGROUND

The prevalence of intracranial aneurysms (IAs) has been proposed to be elevated in the patients with neurofibromatosis type 1 (NF1). Our aims were to determine the prevalence of NF1 in a large Finnish population based cohort of IA patients and, on the other hand, the occurrences of subarachnoid haemorrhage and unruptured intracranial aneurysms in a nationwide population-based cohort of NF1 patients and its matched ten-fold control cohort.

METHODS

The Kuopio IA Database (www.kuopioneurosurgery.fi) includes all ruptured and unruptured IA cases admitted to the Kuopio University Hospital (KUH) from its defined Eastern Finnish catchment population since 1980. In this registry-based study, we cross-linked the Kuopio IA database with the Finnish national registry covering all hospital diagnoses. The NF1 diagnoses of the 4543 patients with either saccular of fusiform IA were identified from 1969 to 2015 and verified from patient records. Our second approach was to analyze the occurrence of aneurysmal subarachnoid haemorrhage (aSAH) and unruptured IAs in a nationwide population-based database of 1410 NF1 patients and its ten-fold matched control cohort (n = 14030) using national registry of hospital diagnoses between 1987 and 2014.

RESULTS

One NF1 patient was identified among the 4543 IA patients. Three verified IA cases (one unruptured IA and two aSAH cases) were identified in the cohort of 1410 NF1 patients, with similar occurrences in the control cohort.

CONCLUSIONS

We found no evidence in our population-based cohorts to support the conception that NF1 is associated with IAs. Our results indicate that the incidence of aSAH is not elevated in patients with NF1. Further studies are required to confirm that there is no association between NF1 and unruptured IAs.