Commentary - (2021) Volume 6, Issue 4
Danon Disease(DD) is an X-linked dominant skeletal and cardiac muscle disorder with multisystem clinical manifestations. It is characterized clinically by the triad of cardio sympathy, and mental retardation. The reins only around 550 Danon disease patients reported in the literature from the first description to the present. Because of the low incidence of Danon disease, it is often missed diagnosis and misdiagnosis in clinic.
This article aims to provide a brief overview of the clinical manifestations, diagnosis and treatment of Danon disease, and provide some ideas for the treatment of Danon. and provide evidence to assist in decision making when assessing DD.
Danon disease • Lysosome-associated membrane protein-2 • Clinical profile • Diagnosis • Treatment
Danon Disease, also known as glycogen storage disorder Ibis, is a rare X-recessive genetic disorder caused by mutations in the liposomal associated membrane protein 2 gene. It was first reported by Danon and colleagues in 1981[1] and then in 2000, Nishino et al. identified a genetic defect in the gene Liposomal Associated Membrane Protein 2 (LAMP2), which encodes the LAMP2 protein [2].Defects in the LAMP2 gene prevent the final stages of auto phage from being completed, which can lead to mitochondrial dysfunction, energy deficiency and oxidative stress [3].As a multi-system genetic disorder, progressive heart failure and arrhythmias are the major causes of death from Danon disease. To date, there is no specific treatment that can be used to prevent the progression of Danon disease.
Due to its characteristic of X recessive inheritance, males are more susceptible to the disease in clinical practice than females, with earlier onset and faster progression [4]. The cardio sympathy of Danon diseases progressive, with male patients often beginning at an early age (before the age of20) and typically presenting with hypertrophy. The ejection fraction and normal lumen size remain constant early in the course of the disease, and then progress to dilated features in 11% to 12% of men [5].
The main cardiac manifestations include left ventricular hypertrophy, ECG abnormalities. In the study of Bounce et al., it was found that up to 80% of patients with Danon disease had abnormal electrical conduction, of which pre-excitation syndrome (WPW) was the most common electrocardiogram manifestation[6]. In our patients, typical hypertrophic cardio sympathy was observed on echocardiography in male patients, while the ECG showed high left ventricular voltage and T-wave inversion, and prolonged QT interval [7].
These patients may have mental disabilities, skeletal sympathy, and muscle weakness as extra cardiac manifestations. Other less common symptoms may also occur, including retinal disease, liver disease and lung disease [8].
Genetic testing for LAMP2 is the gold standard for diagnosis and over 110 different mutations in the LAMP2 gene have been reported. ECG, echocardiography, and magnetic resonance imaging are also important adjuvant tests. Leukocyte LAMP2 protein deficiency detection is a powerful diagnostic tool because of its high sensitivity and high specificity in DD [9]. In addition, electrocardiogram, echocardiogram and magnetic resonance are also important auxiliary examinations. In the differential diagnosis, care should be taken to distinguish DD from other forms of HCM(Hypertrophic cardio sympathy).CMR(Cardiovascular Magnetic Resonance) can be used to distinguish between DD and non-ischemic cardio sympathy and to demonstrate fibrosis progression, which is critical for ICD implantation or HTX decision [10].
Current medical therapies seem to help control symptoms but do little to prevent disease progression. The progression of heart failure in patients with Danon disease is more rapid than that caused by other hypertrophic cardio sympathy. Therefore, clinicians should evaluate it in a timely and regular manner. In addition, some results have been achieved with cardiac ablation for symptomatic arrhythmias. For heart failure patients whose symptoms are difficult to control, a heart transplant may be a last resort [11].
With the increasing incidence of Danon disease in recent years, clinicians should pay attention to the identification of this disease, and comprehensively use electrocardiogram, genetic counseling, genetic testing, and imaging methods to carry out early diagnosis and treatment.
Citation: Yuetong C, et al. A Brief Note on Danon Disease. Med Rep Case Stud, 2021, 06(4):001.
Received: 07-Jun-2021 Published: 28-Jun-2021
Copyright: © 2021 Yuetong C, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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