BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuMucopolysaccharidosis type IAlpha-L-iduronate deficiency; Mucopolysaccharidosis type I; Severe MPS I; Attenuated MPS I; MPS I H; MPS I S; Hurler syndrome; Scheie syndrome; Hurler-Scheie syndrome; MPS 1 H/S; Lysosomal storage disease - mucopolysaccharidosis type IMucopolysaccharidosis type I (MPS I) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules are called glycosaminoglycans (formerly called mucopolysaccharides). As a result, the molecules build up in different parts of the body and cause various health problems.EnzymeEnzymes are complex proteins that cause a specific chemical change. For example, they can help break down the foods we eat so the body can use them....Read Article Now Book Mark Article The condition belongs to a group of diseases called mucopolysaccharidoses (MPSs). MPS I is the most common.MucopolysaccharidosesMucopolysaccharidoses (MPSs) are a group of rare diseases in which the body is missing or does not have enough of an enzyme needed to break down long...Read Article Now Book Mark Article There are several other types of MPSs, including:MPS II (Hunter syndrome) MPS IIMucopolysaccharidosis type II (MPS II) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long ...Read Article Now Book Mark Article MPS III (Sanfilippo syndrome) MPS IIIMucopolysaccharidosis type III (MPS III) is a rare disease in which the body is missing or does not have enough of certain enzymes needed to break do...Read Article Now Book Mark Article MPS IV (Morquio syndrome)MPS IVMucopolysaccharidosis type IV (MPS IV) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long ...Read Article Now Book Mark Article Causes MPS I is inherited, which means that your parents typically pass the disease on to you. If both parents carry a nonworking copy of the gene related to this condition, each of their children has a 25% (1 in 4) chance of developing the disease.People with MPS I do not make an enzyme called lysosomal alpha-L-iduronidase. This enzyme helps break down long chains of sugar molecules called glycosaminoglycans. These molecules are found throughout the body, often in mucus and in fluid around the joints.Without the enzyme, glycosaminoglycans build up and damage organs, including the heart. Symptoms can range from mild to severe. The mild form is called attenuated MPS I and the severe form is called severe MPS I. Symptoms Symptoms of MPS I most often appear from ages 3 to 8 years. Children with severe MPS I develop symptoms earlier than those with the less severe form.Some of the symptoms include:Abnormal bones in the spine Inability to fully open the fingers (claw hand) Claw handClaw hand is a condition that causes curved or bent fingers. This makes the hand appear like the claw of an animal.ImageRead Article Now Book Mark Article Cloudy corneas Cloudy corneasA cloudy cornea is a loss of transparency of the cornea.ImageRead Article Now Book Mark Article Deafness DeafnessHearing loss is being partly or totally unable to hear sound in one or both ears.ImageRead Article Now Book Mark Article Halted growth Heart valve problems Joint disease, including stiffness Intellectual disability that gets worse over time in severe MPS I Intellectual disabilityIntellectual disability is a condition diagnosed before age 18 that includes below-average intellectual function and a lack of skills necessary for d...Read Article Now Book Mark Article Thick, coarse facial features with low nasal bridgeLow nasal bridgeA low nasal bridge is the flattening of the top part of the nose.ImageRead Article Now Book Mark Article Exams and Tests In some states, babies are tested for MPS I as part of the newborn screening tests.Newborn screening testsNewborn screening tests look for developmental, genetic, and metabolic disorders in the newborn baby. This allows steps to be taken before symptoms ...Read Article Now Book Mark Article Other tests that may be done depending on symptoms include:Electrocardiogram (ECG) ElectrocardiogramAn electrocardiogram (ECG) is a test that records the electrical activity of the heart.ImageRead Article Now Book Mark Article Genetic testing for changes to the alpha-L-iduronidase (IDUA) gene Urine tests for extra mucopolysaccharides X-ray of the spine Treatment Enzyme replacement therapy may be recommended. The medicine, called laronidase (Aldurazyme), is given through a vein (IV, intravenously). It replaces the missing enzyme. Talk to your child's provider for more information.Bone marrow transplant has been tried. The treatment has had mixed results.Bone marrow transplantA bone marrow transplant is a procedure to replace damaged or diseased bone marrow with healthy bone marrow stem cells. Bone marrow is the soft, fatt...ImageRead Article Now Book Mark Article Other treatments depend on the organs that are affected. Support Groups More information and support for people with MPS I and their families can be found at:National MPS Society -- mpssociety.org National Organization for Rare Disorders -- rarediseases.org/rare-diseases/mucopolysaccharidosis-type-i NIH Genetic and Rare Diseases Information Center -- rarediseases.info.nih.gov/diseases/10335/mucopolysaccharidosis-type-i Outlook (Prognosis) Children with severe MPS I usually do not do well. Their health problems worsen over time, resulting in death by age 10.Children with attenuated (milder) MPS I have fewer health problems, with many leading fairly normal lives into adulthood. When to Contact a Medical Professional Contact your provider if:You have a family history of MPS I and are considering having children Your child begins to show symptoms of MPS I Prevention Experts recommend genetic counseling and testing for couples with a family history of MPS I who are considering having children. Prenatal testing is available.Genetic counselingGenetics is the study of heredity, the process of a parent passing certain genes on to their children. A person's appearance, such as height, hair co...ImageRead Article Now Book Mark Article Open ReferencesReferencesPyeritz RE. Inherited diseases of connective tissue. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 239.Spranger JW. Mucopolysaccharidoses. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 107.Turnpenny PD, Ellard S, Cleaver R. Inborn errors of metabolism. In: Turnpenny PD, Ellard S, Cleaver R, eds. Emery's Elements of Medical Genetics and Genomics. 16th ed. Philadelphia, PA: Elsevier; 2022:chap 18.AllVideoImagesTogLow nasal bridge - illustration A low or absent nasal bridge can occur in association with infectious diseases or genetic diseases.Low nasal bridgeillustrationLow nasal bridge - illustration A low or absent nasal bridge can occur in association with infectious diseases or genetic diseases.Low nasal bridgeillustrationRelated Information Enzyme(Special Topic) Review Date: 4/24/2023 Reviewed By: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.
Mucopolysaccharidosis type IAlpha-L-iduronate deficiency; Mucopolysaccharidosis type I; Severe MPS I; Attenuated MPS I; MPS I H; MPS I S; Hurler syndrome; Scheie syndrome; Hurler-Scheie syndrome; MPS 1 H/S; Lysosomal storage disease - mucopolysaccharidosis type IMucopolysaccharidosis type I (MPS I) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules are called glycosaminoglycans (formerly called mucopolysaccharides). As a result, the molecules build up in different parts of the body and cause various health problems.EnzymeEnzymes are complex proteins that cause a specific chemical change. For example, they can help break down the foods we eat so the body can use them....Read Article Now Book Mark Article The condition belongs to a group of diseases called mucopolysaccharidoses (MPSs). MPS I is the most common.MucopolysaccharidosesMucopolysaccharidoses (MPSs) are a group of rare diseases in which the body is missing or does not have enough of an enzyme needed to break down long...Read Article Now Book Mark Article There are several other types of MPSs, including:MPS II (Hunter syndrome) MPS IIMucopolysaccharidosis type II (MPS II) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long ...Read Article Now Book Mark Article MPS III (Sanfilippo syndrome) MPS IIIMucopolysaccharidosis type III (MPS III) is a rare disease in which the body is missing or does not have enough of certain enzymes needed to break do...Read Article Now Book Mark Article MPS IV (Morquio syndrome)MPS IVMucopolysaccharidosis type IV (MPS IV) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long ...Read Article Now Book Mark Article Causes MPS I is inherited, which means that your parents typically pass the disease on to you. If both parents carry a nonworking copy of the gene related to this condition, each of their children has a 25% (1 in 4) chance of developing the disease.People with MPS I do not make an enzyme called lysosomal alpha-L-iduronidase. This enzyme helps break down long chains of sugar molecules called glycosaminoglycans. These molecules are found throughout the body, often in mucus and in fluid around the joints.Without the enzyme, glycosaminoglycans build up and damage organs, including the heart. Symptoms can range from mild to severe. The mild form is called attenuated MPS I and the severe form is called severe MPS I. Symptoms Symptoms of MPS I most often appear from ages 3 to 8 years. Children with severe MPS I develop symptoms earlier than those with the less severe form.Some of the symptoms include:Abnormal bones in the spine Inability to fully open the fingers (claw hand) Claw handClaw hand is a condition that causes curved or bent fingers. This makes the hand appear like the claw of an animal.ImageRead Article Now Book Mark Article Cloudy corneas Cloudy corneasA cloudy cornea is a loss of transparency of the cornea.ImageRead Article Now Book Mark Article Deafness DeafnessHearing loss is being partly or totally unable to hear sound in one or both ears.ImageRead Article Now Book Mark Article Halted growth Heart valve problems Joint disease, including stiffness Intellectual disability that gets worse over time in severe MPS I Intellectual disabilityIntellectual disability is a condition diagnosed before age 18 that includes below-average intellectual function and a lack of skills necessary for d...Read Article Now Book Mark Article Thick, coarse facial features with low nasal bridgeLow nasal bridgeA low nasal bridge is the flattening of the top part of the nose.ImageRead Article Now Book Mark Article Exams and Tests In some states, babies are tested for MPS I as part of the newborn screening tests.Newborn screening testsNewborn screening tests look for developmental, genetic, and metabolic disorders in the newborn baby. This allows steps to be taken before symptoms ...Read Article Now Book Mark Article Other tests that may be done depending on symptoms include:Electrocardiogram (ECG) ElectrocardiogramAn electrocardiogram (ECG) is a test that records the electrical activity of the heart.ImageRead Article Now Book Mark Article Genetic testing for changes to the alpha-L-iduronidase (IDUA) gene Urine tests for extra mucopolysaccharides X-ray of the spine Treatment Enzyme replacement therapy may be recommended. The medicine, called laronidase (Aldurazyme), is given through a vein (IV, intravenously). It replaces the missing enzyme. Talk to your child's provider for more information.Bone marrow transplant has been tried. The treatment has had mixed results.Bone marrow transplantA bone marrow transplant is a procedure to replace damaged or diseased bone marrow with healthy bone marrow stem cells. Bone marrow is the soft, fatt...ImageRead Article Now Book Mark Article Other treatments depend on the organs that are affected. Support Groups More information and support for people with MPS I and their families can be found at:National MPS Society -- mpssociety.org National Organization for Rare Disorders -- rarediseases.org/rare-diseases/mucopolysaccharidosis-type-i NIH Genetic and Rare Diseases Information Center -- rarediseases.info.nih.gov/diseases/10335/mucopolysaccharidosis-type-i Outlook (Prognosis) Children with severe MPS I usually do not do well. Their health problems worsen over time, resulting in death by age 10.Children with attenuated (milder) MPS I have fewer health problems, with many leading fairly normal lives into adulthood. When to Contact a Medical Professional Contact your provider if:You have a family history of MPS I and are considering having children Your child begins to show symptoms of MPS I Prevention Experts recommend genetic counseling and testing for couples with a family history of MPS I who are considering having children. Prenatal testing is available.Genetic counselingGenetics is the study of heredity, the process of a parent passing certain genes on to their children. A person's appearance, such as height, hair co...ImageRead Article Now Book Mark Article Open ReferencesReferencesPyeritz RE. Inherited diseases of connective tissue. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 239.Spranger JW. Mucopolysaccharidoses. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 107.Turnpenny PD, Ellard S, Cleaver R. Inborn errors of metabolism. In: Turnpenny PD, Ellard S, Cleaver R, eds. Emery's Elements of Medical Genetics and Genomics. 16th ed. Philadelphia, PA: Elsevier; 2022:chap 18.