Presentation
However, at present, it is considered that Danon disease is not a glycogen storage disease because the disease is caused by the primary deficiency of a lysosomal membrane protein instead of a glycolytic enzyme and detailed pathological features are different [genome.jp]
In 1 family the proband initially presented with HCM as a teenager, which progressed to dilated cardiomyopathy (DCM) and heart failure. Skeletal myopathy and WPW were also noted. [ncbi.nlm.nih.gov]
LAMP2 mutations typically cause multisystem glycogen storage disease but can also present as primary cardiomyopathy, as in our patient. [revespcardiol.org]
Entire Body System
- Disability
Subsequently, she showed signs of mild learning disability and intellectual disability on psychological examinations. [ncbi.nlm.nih.gov]
Danon first described the disease in 2 boys with heart and skeletal muscle disease (muscle weakness), and intellectual disability. [en.wikipedia.org]
Intellectual disability is a variable and inconsistent feature. Cardiac rhythm abnormalities are common and include AV nodal block, atrial fibrillation, and Wolff-Parkinson-White EKG findings. [disorders.eyes.arizona.edu]
Cardiovascular
- Cardiomegaly
A chest X-ray showed cardiomegaly with massive pulmonary congestion. Transthoracic echocardiography demonstrated biventricular symmetrical concentric hypertrophy without left and right outflow tract gradient. [revespcardiol.org]
[…] retardation Mental-retardation [ more ] 0001249 Muscle flaccidity 0010547 Percent of people who have these symptoms is not available through HPO Arrhythmia Abnormal heart rate Heart rhythm disorders Irregular heart beat Irregular heartbeat [ more ] 0011675 Cardiomegaly [rarediseases.info.nih.gov]
Our patients showed the full spectrum of both prenatal signs (hydrops, polyhydramnios) and postnatal signs (hypotonia, hyporeflexia, absence of active movements, cardiomegaly), which have been reported previously. [link.springer.com]
Autopsy or explant specimens examined at the time of transplantation reveal cardiomegaly with ventricular hypertrophy and biatrial and biventricular dilatation. [flipper.diff.org]
It was initially described by Danon MJ in 1981, who described two 16-year-old men with mental retardation, cardiomegaly, and proximal skeletal myopathy, in whom they demonstrated accumulation of glycogen in their muscles without alterations in the enzymes [scielo.org.mx]
Musculoskeletal
- Proximal Muscle Weakness
We describe two patients: the first patient presented with severe hypertrophic cardiomyopathy, Wolff-Parkinson-White syndrome, proximal muscle weakness, and chronic painless diarrhea; the second patient manifested as limb-girdle muscle weakness, mild [ncbi.nlm.nih.gov]
Pes cavus High-arched foot 0001761 Proximal muscle weakness Weakness in muscles of upper arms and upper legs 0003701 Visual impairment Impaired vision Loss of eyesight Poor vision [ more ] 0000505 Wolff-Parkinson-White syndrome 0001716 X-linked dominant [rarediseases.info.nih.gov]
Myopathy Skeletal myopathy manifests as progressive proximal muscle weakness of the shoulders, neck, and legs 1 in 80% to 90% of men. 16, 25 Weakness is seldom debilitating, and patients usually retain the ability to walk as adults. [circheartfailure.ahajournals.org]
- Diffuse Muscle Wasting
On neurological examination, he complained of visual loss, and diffuse muscle wasting and weakness were also unexpectedly noted. Electromyography evidenced a myopathic pattern and a peripheral neuropathy. [ncbi.nlm.nih.gov]
Workup
Early involvement of electrophysiology and early consideration of ICD implantation for symptomatic arrhythmias Skeletal myopathy Formal neuromuscular evaluation Physical therapy and rehabilitation Muscle biopsy may be performed as part of diagnostic workup [circheartfailure.ahajournals.org]
Treatment
Treatment Treatment Options: No known treatment is available for the ocular disease. Transplantation can be an effective treatment for the cardiomyopathy which can be lethal even in adolescents. [disorders.eyes.arizona.edu]
Examinations performed before and during treatment included visual acuity (VA), spectral-domain optical coherence tomography, and electroretinography. Following total 48 weeks of treatment, VA decreased from 20/30 OD, 20/200 OS, to 20/40 OD, CF OS. [ncbi.nlm.nih.gov]
Initially, immunosuppression was modified (treatment with mycophenolic acid 900 mg/d was discontinued, whereas treatment with tacrolimus 2.5 mg/d was unchanged), and the patient received a total of 4 doses of rituximab weekly without sufficient response [journals.lww.com]
Treatment: There is no specific treatment for this disorder. Treatment is based specifically on any present symptoms and also aims to provide support in the care of the individual. Most treatment is based on heart problems related to this disorder. [medigoo.com]
Prognosis
Female patients most often present with late-onset cardiomyopathy and slow disease progression, but early-onset cases with unfavorable prognosis have been reported. [ncbi.nlm.nih.gov]
Prognosis Patients are at risk of sudden death due to arrhythmia during early adulthood. The documents contained in this web site are presented for information purposes only. [orpha.net]
Given the poor prognosis associated with cardiomyopathy due to LAMP2 mutation, early diagnosis is critical for determining the appropriate treatment strategy and achieving timely cardiac transplantation, the only effective therapeutic option. [revespcardiol.org]
To distinguish sarcomeric HCM from Danon’s disease is important, as the pathophysiology, clinical evolution, prognosis, mode of inheritance, and therefore genetic counselling are very different As a first step, all patients with HCM should be considered [escardio.org]
In this study, we report details of the clinical Danon disease phenotype and prognosis based on data from 82 individuals from 36 families with Danon disease that contacted our group. [nature.com]
Etiology
In this case, morphological examination of muscle biopsy, showing lysosomal storage myopathy, and immunohistochemistry analyses can provide key elements for orienting etiologic investigations. [ncbi.nlm.nih.gov]
Etiology The disease is caused by mutations in the LAMP2 gene, localised to Xq24. The LAMP2 protein is an essential component of the lysosomal membrane and appears to play a role in autophagosome-lysosome fusion. [orpha.net]
Keywords : Autophagy, neurodegenerative disorders, neurodevelopmental disorders, psychiatric disorders, etiology, treatment mechanism Important Note : All contributions to this Research Topic must be within the scope of the section and journal to which [frontiersin.org]
The etiology of the disease is associated with mutations in the LAMP2 gene on chromosome X. To date, only mutations in the LAMP2 gene have been associated with the disease. [scielo.org.mx]
Epidemiology
Summary Epidemiology More than 20 families have been described in the literature so far. Clinical description The disease classically manifests in males over 10 years of age. [orpha.net]
Conclusions: Danon disease requires further studies in order to obtain epidemiological data for this condition. To date, only mutations in the LAMP2 gene have been documented as the main etiology of Danon disease. [scielo.org.mx]
EPIDEMIOLOGY The incidence of Danon Disease has not been determined. HCM is estimated to be present in 2 of every 1000 young adults, according to one large study. Charron et al. examined 197 independent index cases with HCM. [flipper.diff.org]
[…] to the late-onset cases that can occur, may result from an uneven distribution of LAMP2 protein in cardiac muscle, with the protein lacking in some large portions of the muscle, while its expression is preserved in other large myocardial areas. [7] Epidemiology [emedicine.medscape.com]
Molecular epidemiology of hypertrophic cardiomyopathy. Cold Spring Harb Symp Quant Biol 2002 ;67: 383 - 388 24. Maron BJ. Hypertrophic cardiomyopathy: a systematic review. JAMA 2002 ;287: 1308 - 1320 25. Maron BJ, Gross BW, Stark SI. [nejm.org]
Pathophysiology
However, the precise pathophysiological mechanism through which LAMP-2 deficiency causes Danon disease is still not fully understood and its elucidation would promote the development of new therapies. [ncbi.nlm.nih.gov]
The rapid advances from genetic discovery to and understanding of pathophysiology to treatment development ensures that additional studies in rare genetic conditions will shortly be arriving on the scene. Matthew R. G. [ucdenver.edu]
These models will be validated by determining their distinct pathophysiologic characteristics in comparison to those from both Danon patients and wild type controls. [grantome.com]
Prevention
Abstract We report the case of an 18-year-old man with Danon disease, a genetic disorder inclunding a severe hypertrophic cardiomyopathy with very broad QRS, who had an implantable cardioverter defibrillator for primary prevention. [ncbi.nlm.nih.gov]
What if I am asked to sign an agreement that prevents me from reporting my concerns directly to the SEC? Such an agreement may violate the federal securities laws. [sec.gov]
[…] features are possibly due to reduced membrane proliferation and vesicular movement in the overcrowded muscle fibers of Pompe disease, and to the membrane remodelling occurring only in patients with late-onset GSDII, which would be a protective mechanism to prevent [research.unipd.it]
This DNA vaccine has the potential to be a safe and effective therapy to prevent Alzheimer disease. He described Machado-Joseph disease (MJD), an autosomal dominant ataxia, with William Nyhan, M.D. Ph.D, in 1976, for the first time. [books.google.com]