Metachromatic leukodystrophy
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Chiranjeevi Sainatham, M.B.B.S[2]
Synonyms and keywords: Arylsulfatase A deficiency
Overview
Metachromatic leukodystrophy is the most common form of a family of genetic diseases known as the leukodystrophies, diseases which affect the growth and/or development of myelin, the fatty covering which acts as an insulator around nerve fibres throughout the central and peripherial nervous systems .
Classification
Based on the age of onset, Metachromatic Leukodystrophy is classified into three types.
Types:
- Late infantile onset (before 30 months)
- Juvenile onset ( 2.5 years to 16 years)
- Adult onset
Pathophysiology
Metachromatic leukodystrophy is caused by deficiency of Arylsulfatase A (ASA), an autosomal recessive disorder.
Causes
Disease name] may be caused by [cause1], [cause2], or [cause3].
OR
Common causes of [disease] include [cause1], [cause2], and [cause3].
OR
The most common cause of [disease name] is [cause 1]. Less common causes of [disease name] include [cause 2], [cause 3], and [cause 4].
OR
The cause of [disease name] has not been identified. To review risk factors for the development of [disease name], click here.
Differentiating Metachromatic leukodystrophy from other Diseases
[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as [differential dx1], [differential dx2], and [differential dx3].
OR
[Disease name] must be differentiated from [[differential dx1], [differential dx2], and [differential dx3].
Epidemiology and Demographics
The incidence/prevalence of [disease name] is approximately [number range] per 100,000 individuals worldwide.
OR
In [year], the incidence/prevalence of [disease name] was estimated to be [number range] cases per 100,000 individuals worldwide.
OR
In [year], the incidence of [disease name] is approximately [number range] per 100,000 individuals with a case-fatality rate of [number range]%.
Patients of all age groups may develop [disease name].
OR
The incidence of [disease name] increases with age; the median age at diagnosis is [#] years.
OR
[Disease name] commonly affects individuals younger than/older than [number of years] years of age.
OR
[Chronic disease name] is usually first diagnosed among [age group].
OR
[Acute disease name] commonly affects [age group].
There is no racial predilection to [disease name].
OR
[Disease name] usually affects individuals of the [race 1] race. [Race 2] individuals are less likely to develop [disease name].
[Disease name] affects men and women equally.
OR
[Gender 1] are more commonly affected by [disease name] than [gender 2]. The [gender 1] to [gender 2] ratio is approximately [number > 1] to 1.
The majority of [disease name] cases are reported in [geographical region].
OR
[Disease name] is a common/rare disease that tends to affect [patient population 1] and [patient population 2].
Risk Factors
There are no established risk factors for [disease name].
OR
The most potent risk factor in the development of [disease name] is [risk factor 1]. Other risk factors include [risk factor 2], [risk factor 3], and [risk factor 4].
OR
Common risk factors in the development of [disease name] include [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
OR
Common risk factors in the development of [disease name] may be occupational, environmental, genetic, and viral.
Screening
There is insufficient evidence to recommend routine screening for [disease/malignancy].
OR
According to the [guideline name], screening for [disease name] is not recommended.
OR
According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with [condition 1], [condition 2], and [condition 3].
Natural History, Complications, and Prognosis
If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
OR
Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
OR
Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [#]%.
Diagnosis
Diagnostic Study of Choice
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
OR
The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
OR
The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].
OR
There are no established criteria for the diagnosis of [disease name].
History and Symptoms
The majority of patients with [disease name] are asymptomatic.
OR
The hallmark of [disease name] is [finding]. A positive history of [finding 1] and [finding 2] is suggestive of [disease name]. The most common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3]. Common symptoms of [disease] include [symptom 1], [symptom 2], and [symptom 3]. Less common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3].
Physical Examination
Patients with [disease name] usually appear [general appearance]. Physical examination of patients with [disease name] is usually remarkable for [finding 1], [finding 2], and [finding 3].
OR
Common physical examination findings of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
The presence of [finding(s)] on physical examination is diagnostic of [disease name].
OR
The presence of [finding(s)] on physical examination is highly suggestive of [disease name].
Laboratory Findings
An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].
OR
Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
OR
[Test] is usually normal among patients with [disease name].
OR
Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].
OR
There are no diagnostic laboratory findings associated with [disease name].
Electrocardiogram
There are no ECG findings associated with [disease name].
OR
An ECG may be helpful in the diagnosis of [disease name]. Findings on an ECG suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
X-ray
There are no x-ray findings associated with [disease name].
OR
An x-ray may be helpful in the diagnosis of [disease name]. Findings on an x-ray suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no x-ray findings associated with [disease name]. However, an x-ray may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with [disease name].
OR
Echocardiography/ultrasound may be helpful in the diagnosis of [disease name]. Findings on an echocardiography/ultrasound suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no echocardiography/ultrasound findings associated with [disease name]. However, an echocardiography/ultrasound may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
CT scan
There are no CT scan findings associated with [disease name].
OR
[Location] CT scan may be helpful in the diagnosis of [disease name]. Findings on CT scan suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no CT scan findings associated with [disease name]. However, a CT scan may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
MRI
There are no MRI findings associated with [disease name].
OR
[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no MRI findings associated with [disease name]. However, a MRI may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Other Imaging Findings
There are no other imaging findings associated with [disease name].
OR
[Imaging modality] may be helpful in the diagnosis of [disease name]. Findings on an [imaging modality] suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
Other Diagnostic Studies
There are no other diagnostic studies associated with [disease name].
OR
[Diagnostic study] may be helpful in the diagnosis of [disease name]. Findings suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
Other diagnostic studies for [disease name] include [diagnostic study 1], which demonstrates [finding 1], [finding 2], and [finding 3], and [diagnostic study 2], which demonstrates [finding 1], [finding 2], and [finding 3].
Treatment
Medical Therapy
There is no treatment for [disease name]; the mainstay of therapy is supportive care.
OR
Supportive therapy for [disease name] includes [therapy 1], [therapy 2], and [therapy 3].
OR
The majority of cases of [disease name] are self-limited and require only supportive care.
OR
[Disease name] is a medical emergency and requires prompt treatment.
OR
The mainstay of treatment for [disease name] is [therapy].
OR The optimal therapy for [malignancy name] depends on the stage at diagnosis.
OR
[Therapy] is recommended among all patients who develop [disease name].
OR
Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].
OR
Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].
OR
Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].
OR
Patients with [disease subclass 1] are treated with [therapy 1], whereas patients with [disease subclass 2] are treated with [therapy 2].
Surgery
Surgical intervention is not recommended for the management of [disease name].
OR
Surgery is not the first-line treatment option for patients with [disease name]. Surgery is usually reserved for patients with either [indication 1], [indication 2], and [indication 3]
OR
The mainstay of treatment for [disease name] is medical therapy. Surgery is usually reserved for patients with either [indication 1], [indication 2], and/or [indication 3].
OR
The feasibility of surgery depends on the stage of [malignancy] at diagnosis.
OR
Surgery is the mainstay of treatment for [disease or malignancy].
Primary Prevention
There are no established measures for the primary prevention of [disease name].
OR
There are no available vaccines against [disease name].
OR
Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
OR
[Vaccine name] vaccine is recommended for [patient population] to prevent [disease name]. Other primary prevention strategies include [strategy 1], [strategy 2], and [strategy 3].
Secondary Prevention
There are no established measures for the secondary prevention of [disease name].
OR
Effective measures for the secondary prevention of [disease name] include [strategy 1], [strategy 2], and [strategy 3].
Clinical Trials
Enzyme Replacement Therapy
- Phase II clinical trials are underway in Europe by a Danish company, Zymenex, using Metazym, (updated August 2007)
- Shire Human Genetics is proposing an enzyme replacement therapy
See also
External links
- Large portions of this article are courtesy of the public domain text available at the National Institute of Neurological Disorders and Stroke [3]
- Further information regarding MLD, treatments, genetics, and current research projects, can be found at:
- eMedicine article about MLD by Theodore Moore, MD.
- mld at NIH/UW GeneTests
References
Template:Metabolic pathology fi:Metakromaattinen leukodystrofia