Reviews & Analysis

This PrimeView accompanies the Primer on Merkel cell carcinoma by Becker and colleagues and focuses on the mechanisms that underlie the pathogenesis of this rare but highly metastatic cutaneous cancer.

Merkel cell carcinoma (MCC) is a rare, highly metastatic skin cancer. MCC pathogenesis is associated with either the presence of Merkel cell polyomavirus or chronic exposure to ultraviolet light, which can cause a characteristic pattern of multiple DNA mutations.

Idiopathic pulmonary fibrosis is a chronic, progressive and irreversible interstitial lung disease that is characterized by fibrotic scarring of the lung parenchyma. This PrimeView summarizes the potential mechanisms underlying the condition.

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by progressive lung scarring that is thought to occur in a genetically susceptible, ageing individual through aberrant reparative responses to repeated injury to the alveolar epithelium. This Primer summarizes the processes thought to underlie the development of IPF and clinical challenges faced in treating patients with this irreversible condition.

Syphilis is a sexually and vertically transmitted infection caused by the spirochaete Treponema pallidum. This PrimeView highlights the importance of screening in pregnant women to eliminate mother-to-child transmission, which causes several hundred thousand stillbirths and neonatal deaths every year.

Syphilis is a sexually and vertically transmitted infection caused by Treponema pallidum. Although curable, syphilis is re-emerging as a global public health problem, particularly among men who have sex with men in developed countries, and as a major cause of stillbirths and neonatal deaths in developing nations. This Primer summarizes our current understanding of the pathogen and describes ongoing efforts towards global elimination.

The symptoms of amyotrophic lateral sclerosis (ALS) include signs of upper motor neuron and lower motor neuron dysfunction. These symptoms, and the diagnostic work-up for ALS, are the main focus of this PrimeView, which accompanies the Primer by Hardiman and colleagues.

Amyotrophic lateral sclerosis (ALS) is characterized by the degeneration of both upper and lower motor neurons, which leads to progressive muscle weakness and paralysis. This Primer by Hardiman and colleagues provides a detailed overview of the epidemiology, pathophysiology and diagnosis of ALS, and discusses the management of both the motor and non-motor symptoms of this condition.

In most cases, fragile X syndrome is caused by a trinucleotide repeat expansion in FMR1, which results in loss of expression of its gene product, fragile X mental retardation 1 protein (FMRP). This PrimeView focuses on the consequences of FMRP loss, including deficits in synpatic plasticity.

Fragile X syndrome (FXS) is characterized by severe behavioural alterations, such as hyperactivity, anxiety and symptoms of autism spectrum disorder. These behavioural manifestations, in addition to the molecular pathophysiology, diagnosis and management of FXS, are reviewed in this Primer.

Severe childhood malnutrition develops as a consequence of several social, economic and political factors. These factors are highlighted in this illustrated PrimeView, which accompanies the Primer by Bhutta et al.

Children with severe malnutrition (which includes severe wasting and kwashiorkor) have an elevated risk of serious illness and death, primarily from acute infectious diseases. In this Primer, the authors describe the multifactorial aetiology of severe malnutrition and the efforts needed to meet the United Nations’ Sustainable Development Goal of zero hunger.

Snakebite envenoming is a neglected tropical disease that affects 1.8–2.7 million people worldwide, especially in impoverished areas of the warmer tropics and subtropics. Clinical manifestations vary from local tissue damage to life-threatening systemic effects and chronic disability, such as amputation.

Snakebite envenoming is a neglected tropical disease that particularly affects impoverished populations in the rural tropics. This Primer describes the efforts toward reducing the burden of snakebites, which require input from private, public and non-profit stakeholders worldwide.

Chronic pancreatitis is attributed to alcohol abuse in the majority of cases. Tobacco smoking is an independent risk factor; other causes include genetic factors, metabolic disorders, chronic obstructive causes (for example, ductal stones), autoimmunity and idiopathic mechanisms.

Chronic pancreatitis is characterized by chronic inflammation of the pancreas that results in progressive scarring of the pancreatic tissue, pain and pancreatic gland dysfunction. In this Primer, Kleeff et al. describe the current understanding of chronic pancreatitis and its complications.

Hypoparathyroidism is characterized by hypocalcaemia and inadequately low circulating levels of parathyroid hormone. This PrimeView focuses on the different causes of this rare condition, which include damage or inadvertent removal of the parathyroid gland during neck surgery and genetic, idiopathic and autoimmune aetiologies.

Hypoparathyroidism is a disease characterized by inadequately low circulating levels of parathyroid hormone resulting in low calcium levels and increased phosphate levels in the blood. In this Primer, Mannstadt et al. summarize current knowledge of the prevalence, pathophysiology, clinical presentation and management of hypoparathyroidism.

This illustrated PrimeView accompanies the Primer on Heart failure with reduced ejection fraction by Butler and colleagues, and focuses on the diagnosis and staging of heart failure, which is crucial for the management of patients.

Heart failure can be broadly divided into two categories: heart failure with preserved ejection fraction and heart failure with reduced ejection fraction (HFrEF). HFrEF accounts for approximately 50% of all cases of heart failure in the United States and is the focus of this Primer by Butler and colleagues.