Hunter syndrome: Difference between revisions
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{{Infobox medical condition | |||
| name = Hunter syndrome | |||
| image = [[File:Mucopolysaccharidosis_(Hunter's_Syndrome)_3.jpg|alt=Hunter syndrome]] | |||
| caption = A child with Hunter syndrome | |||
| synonyms = Mucopolysaccharidosis type II, MPS II | |||
| pronounce = | |||
| specialty = [[Medical genetics]] | |||
| symptoms = [[Developmental delay]], [[hepatosplenomegaly]], [[joint stiffness]], [[coarse facial features]] | |||
| onset = Usually between ages 2 and 4 | |||
| duration = Lifelong | |||
| causes = [[Genetic mutation]] in the [[IDS gene]] | |||
| risks = Family history | |||
| diagnosis = [[Genetic testing]], [[urine test]] for [[glycosaminoglycans]] | |||
| differential = [[Hurler syndrome]], [[Sanfilippo syndrome]], [[Morquio syndrome]] | |||
| treatment = [[Enzyme replacement therapy]], [[hematopoietic stem cell transplantation]] | |||
| medication = [[Idursulfase]] | |||
| prognosis = Variable, often reduced lifespan | |||
| frequency = 1 in 100,000 to 1 in 170,000 male births | |||
| deaths = | |||
}} | |||
{{Short description|A rare genetic disorder affecting metabolism}} | {{Short description|A rare genetic disorder affecting metabolism}} | ||
[[File:X-linked recessive.svg|X-linked recessive inheritance|thumb|left]] | |||
[[File:Dermatan sulfate.svg|Dermatan sulfate|thumb|left]] | |||
'''Hunter syndrome''', also known as '''mucopolysaccharidosis type II''' (MPS II), is a rare genetic disorder that primarily affects males. It is one of the [[lysosomal storage disorders]] and is caused by a deficiency of the enzyme iduronate-2-sulfatase. This enzyme deficiency leads to the accumulation of glycosaminoglycans (GAGs) in the body's cells, which can cause a variety of symptoms and complications. | '''Hunter syndrome''', also known as '''mucopolysaccharidosis type II''' (MPS II), is a rare genetic disorder that primarily affects males. It is one of the [[lysosomal storage disorders]] and is caused by a deficiency of the enzyme iduronate-2-sulfatase. This enzyme deficiency leads to the accumulation of glycosaminoglycans (GAGs) in the body's cells, which can cause a variety of symptoms and complications. | ||
==Genetics== | ==Genetics== | ||
Hunter syndrome is an [[X-linked recessive]] disorder, meaning the defective gene is located on the X chromosome. Since males have only one X chromosome, a single defective gene is sufficient to cause the disorder. Females, having two X chromosomes, are typically carriers and usually do not exhibit symptoms, although some may have mild manifestations. | Hunter syndrome is an [[X-linked recessive]] disorder, meaning the defective gene is located on the X chromosome. Since males have only one X chromosome, a single defective gene is sufficient to cause the disorder. Females, having two X chromosomes, are typically carriers and usually do not exhibit symptoms, although some may have mild manifestations. | ||
==Pathophysiology== | ==Pathophysiology== | ||
The enzyme iduronate-2-sulfatase is responsible for breaking down complex molecules known as glycosaminoglycans. In individuals with Hunter syndrome, the deficiency of this enzyme leads to the accumulation of GAGs, such as dermatan sulfate and heparan sulfate, in various tissues. This accumulation disrupts normal cellular function and leads to the symptoms associated with the disorder. | The enzyme iduronate-2-sulfatase is responsible for breaking down complex molecules known as glycosaminoglycans. In individuals with Hunter syndrome, the deficiency of this enzyme leads to the accumulation of GAGs, such as dermatan sulfate and heparan sulfate, in various tissues. This accumulation disrupts normal cellular function and leads to the symptoms associated with the disorder. | ||
==Symptoms== | ==Symptoms== | ||
The symptoms of Hunter syndrome can vary widely among affected individuals and may include: | The symptoms of Hunter syndrome can vary widely among affected individuals and may include: | ||
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* Heart valve abnormalities | * Heart valve abnormalities | ||
* Respiratory issues | * Respiratory issues | ||
Symptoms typically appear between the ages of 2 and 4 years and can progress over time. The severity of the disorder can range from mild to severe. | Symptoms typically appear between the ages of 2 and 4 years and can progress over time. The severity of the disorder can range from mild to severe. | ||
==Diagnosis== | ==Diagnosis== | ||
Diagnosis of Hunter syndrome is based on clinical evaluation, family history, and laboratory tests. Enzyme assays can measure the activity of iduronate-2-sulfatase in blood or skin cells. Genetic testing can confirm the diagnosis by identifying mutations in the IDS gene. | Diagnosis of Hunter syndrome is based on clinical evaluation, family history, and laboratory tests. Enzyme assays can measure the activity of iduronate-2-sulfatase in blood or skin cells. Genetic testing can confirm the diagnosis by identifying mutations in the IDS gene. | ||
==Treatment== | ==Treatment== | ||
Currently, there is no cure for Hunter syndrome, but treatments are available to manage symptoms and improve quality of life. These include: | Currently, there is no cure for Hunter syndrome, but treatments are available to manage symptoms and improve quality of life. These include: | ||
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* Supportive care, such as physical therapy, occupational therapy, and speech therapy. | * Supportive care, such as physical therapy, occupational therapy, and speech therapy. | ||
* Surgical interventions for complications like carpal tunnel syndrome or heart valve issues. | * Surgical interventions for complications like carpal tunnel syndrome or heart valve issues. | ||
==Prognosis== | ==Prognosis== | ||
The prognosis for individuals with Hunter syndrome varies depending on the severity of the condition. Those with a milder form may live into adulthood, while those with a more severe form may have a reduced life expectancy due to complications such as respiratory failure or cardiac issues. | The prognosis for individuals with Hunter syndrome varies depending on the severity of the condition. Those with a milder form may live into adulthood, while those with a more severe form may have a reduced life expectancy due to complications such as respiratory failure or cardiac issues. | ||
==See also== | |||
== | |||
* [[Lysosomal storage disorder]] | * [[Lysosomal storage disorder]] | ||
* [[Mucopolysaccharidosis]] | * [[Mucopolysaccharidosis]] | ||
* [[Genetic disorder]] | * [[Genetic disorder]] | ||
* [[Enzyme replacement therapy]] | * [[Enzyme replacement therapy]] | ||
[[Category:Genetic disorders]] | [[Category:Genetic disorders]] | ||
[[Category:Lysosomal storage disorders]] | [[Category:Lysosomal storage disorders]] | ||
[[Category:Rare diseases]] | [[Category:Rare diseases]] | ||
Latest revision as of 21:14, 9 April 2025
Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD's medical weight loss NYC, sleep center NYC
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| Hunter syndrome | |
|---|---|
_3.jpg)
| |
| Synonyms | Mucopolysaccharidosis type II, MPS II |
| Pronounce | |
| Specialty | Medical genetics |
| Symptoms | Developmental delay, hepatosplenomegaly, joint stiffness, coarse facial features |
| Complications | N/A |
| Onset | Usually between ages 2 and 4 |
| Duration | Lifelong |
| Types | N/A |
| Causes | Genetic mutation in the IDS gene |
| Risks | Family history |
| Diagnosis | Genetic testing, urine test for glycosaminoglycans |
| Differential diagnosis | Hurler syndrome, Sanfilippo syndrome, Morquio syndrome |
| Prevention | N/A |
| Treatment | Enzyme replacement therapy, hematopoietic stem cell transplantation |
| Medication | Idursulfase |
| Prognosis | Variable, often reduced lifespan |
| Frequency | 1 in 100,000 to 1 in 170,000 male births |
| Deaths | |
A rare genetic disorder affecting metabolism
Hunter syndrome, also known as mucopolysaccharidosis type II (MPS II), is a rare genetic disorder that primarily affects males. It is one of the lysosomal storage disorders and is caused by a deficiency of the enzyme iduronate-2-sulfatase. This enzyme deficiency leads to the accumulation of glycosaminoglycans (GAGs) in the body's cells, which can cause a variety of symptoms and complications.
Genetics[edit]
Hunter syndrome is an X-linked recessive disorder, meaning the defective gene is located on the X chromosome. Since males have only one X chromosome, a single defective gene is sufficient to cause the disorder. Females, having two X chromosomes, are typically carriers and usually do not exhibit symptoms, although some may have mild manifestations.
Pathophysiology[edit]
The enzyme iduronate-2-sulfatase is responsible for breaking down complex molecules known as glycosaminoglycans. In individuals with Hunter syndrome, the deficiency of this enzyme leads to the accumulation of GAGs, such as dermatan sulfate and heparan sulfate, in various tissues. This accumulation disrupts normal cellular function and leads to the symptoms associated with the disorder.
Symptoms[edit]
The symptoms of Hunter syndrome can vary widely among affected individuals and may include:
- Developmental delay
- Coarse facial features
- Enlarged liver and spleen (hepatosplenomegaly)
- Joint stiffness
- Hearing loss
- Heart valve abnormalities
- Respiratory issues
Symptoms typically appear between the ages of 2 and 4 years and can progress over time. The severity of the disorder can range from mild to severe.
Diagnosis[edit]
Diagnosis of Hunter syndrome is based on clinical evaluation, family history, and laboratory tests. Enzyme assays can measure the activity of iduronate-2-sulfatase in blood or skin cells. Genetic testing can confirm the diagnosis by identifying mutations in the IDS gene.
Treatment[edit]
Currently, there is no cure for Hunter syndrome, but treatments are available to manage symptoms and improve quality of life. These include:
- Enzyme replacement therapy (ERT) with idursulfase, which can help reduce GAG accumulation.
- Supportive care, such as physical therapy, occupational therapy, and speech therapy.
- Surgical interventions for complications like carpal tunnel syndrome or heart valve issues.
Prognosis[edit]
The prognosis for individuals with Hunter syndrome varies depending on the severity of the condition. Those with a milder form may live into adulthood, while those with a more severe form may have a reduced life expectancy due to complications such as respiratory failure or cardiac issues.
