Mucopolysaccharidoses

The mucopolysaccharidoses, a subset of the lysosomal storage diseases, are a group of inherited disorders characterized by absent or defective enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body's constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes needed to break down carbohydrate chains called glycosaminoglycans (GAGs). These disorders lead to the accumulation of GAGs within cells, resulting in a variety of health problems. Most patients appear healthy at birth, but physical and/or mental function deteriorates as accumulation progresses. With disease progression, multiple organ systems may be affected. The diagnosis can be made by measuring urine GAG concentrations and by performing enzyme assays to identify the enzyme deficiency. Management depends on the specific disorder, degree of accumulation, and degree of deformity.

Last update:

Table of Contents

Share this concept:

Share on facebook
Share on twitter
Share on linkedin
Share on reddit
Share on email
Share on whatsapp

Overview

Definition

Mucopolysaccharidoses (MPSs) are a group of genetic metabolic diseases due to absent or defective enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body's constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes needed to break down carbohydrate chains called glycosaminoglycans (GAGs).

Etiology and classification

The MPSs are all inherited and classified on the basis of the enzyme deficiency.

  • MPS I:
    • Autosomal recessive 
    • Deficiency of alpha-L-iduronidase
  • MPS II:
    • Also known as Hunter syndrome
    • X-linked 
    • Deficiency of iduronate sulfatase
  • MPS III:
    • Also known as Sanfilippo syndrome
    • Autosomal recessive
    • Divided into 4 clinical entities on the basis of distinct enzyme deficiencies that are needed to break down heparan sulfate carbohydrate chains:
      • MPS IIIA: deficiency of heparan N-sulfatase
      • MPS IIIB: deficiency of alpha-N-acetylglucosaminidase
      • MPS IIIC: deficiency of acetyl coenzyme A (acetyl-CoA):alpha-glucosaminide acetyltransferase
      • MPS IIID: deficiency of N-acetylglucosamine 6-sulfatase
  • MPS IV:
    • Also known as Morquio syndrome
    • Autosomal recessive
    • Divided into 2 clinical entities on the basis of distinct enzyme deficiencies that are needed to break down keratan sulfate carbohydrate chains:
      • MPS IVA: deficiency of galactosamine-6-sulfate sulfatase
      • MPS IVB: deficiency of beta-galactosidase
  • MPS VI:
    • Also known as Maroteaux-Lamy syndrome
    • Autosomal recessive
    • Deficiency of N-acetylgalactosamine 4-sulfatase
  • MPS VII:
    • Also known as Sly syndrome
    • Autosomal recessive 
    • Deficiency of  enzyme beta-glucuronidase
  • MPX IX:
    • Autosomal recessive 
    • Deficiency of hyaluronidase

Epidemiology

  • Incidence: 1 in 25,000 live births 
  • Based on type:
    • Severe MPS I: 1 in 100,000 
    • Attenuated MPS I: 0.2–1 in 100,000 live births 
    • MPS II: approximately 1 in 100,000 live male births
    • MPS III (all 4 types combined): 1 in 70,000 live births
    • MPS IV: 1 in 200,000 live births
    • MPS VII: 1 in 250,000 live births
    • MPS IX: only 1 reported case

Pathophysiology

  • Lysosomes:
    • Cytoplasmic organelle cells containing degradative enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body's constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes enclosed in a membrane
    • Degradative enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body's constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes are targeted at specific proteins, nucleic acids Nucleic Acids Nucleic acids are polymers of nucleotides, organic molecules composed of a sugar, a phosphate group, and a nitrogenous base. Nucleic acids are responsible for storage, replication, and expression of genetic information. The 2 nucleic acids most commonly seen in eukaryotic cells are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic Acids, carbohydrates Carbohydrates Carbohydrates are one of the 3 macronutrients, along with fats and proteins, serving as a source of energy to the body. These biomolecules store energy in the form of glycogen and starch, and play a role in defining the cellular structure (e.g., cellulose). Basics of Carbohydrates, or lipids.
  • Lysosomal storage diseases:
    • Deficiency of these degradative enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body's constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes halts target processing and/or destruction of these molecules.
    • Molecular accumulation in tissues leads to disease.
  • MPSs:
    • Deficiency of lysosomal enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body's constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes needed to metabolize GAGs
    • GAGs are long carbohydrate chains present in several tissues: 
      • Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Structure of Bones
      • Cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage
      • Tendons
      • Corneas
      • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin
      • Connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue
      • Solid and luminal organs
    • Glycosaminoglycans and/or metabolites accumulate in cells or connective tissues.
    • Progressive cellular damage ensues.
    • Appearance and physical, mental, organ, and system functions may be affected.

Clinical Presentation

Affected individuals are usually not affected at birth, but they experience disease progression as they age. Clinical features vary based on the MPS type.

MPS I

Divided into 3 clinical entities based on disease severity (less severe forms referred to as attenuated):

  • Hurler syndrome (most severe):
    • Developmental delay by 1 year of age
    • Arrested development between ages 2 and 4 years
    • Frequently, death by age 10 (usually from cardiopulmonary complications)
  • Hurler-Scheie syndrome (intermediate severity):
    • Symptom onset between 3 and 8 years
    • Life expectancy: late teens to early 20s
  • Scheie syndrome (least severe):
    • Symptom onset between 5 and 10 years
    • Can live into adulthood

Distinguishing clinical features (more or less pronounced depending on severity):

  • Mental/cognitive impairment
  • Language limitation
  • Hearing loss Hearing loss Hearing loss, also known as hearing impairment, is any degree of impairment in the ability to apprehend sound as determined by audiometry to be below normal hearing thresholds. Clinical presentation may occur at birth or as a gradual loss of hearing with age, including a short-term or sudden loss at any point. Hearing Loss
  • Poor vision:
    • Corneal clouding
    • Retinal degeneration
  • Dysostosis multiplex:
    • Compressed spine
    • Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Structure of Bones/joint abnormalities
    • Joint restriction and contractures
    • Carpal tunnel syndrome Carpal Tunnel Syndrome Carpal tunnel syndrome (CTS) is a complex of signs and symptoms caused by compression of the median nerve as it crosses the carpal tunnel. Presentation is with pain and paresthesia of the dermatomal target tissues innervated by the median nerve as well as weakness and atrophy of the nerve's myotomal targets. Carpal Tunnel Syndrome
  • Distinct facial features:
    • Coarse features
    • Flat midface
    • Depressed nasal bridge
    • Bulging forehead
    • Small jaws
    • Widely spaced teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth
    • Peg-shaped teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth
    • Macroglossia
  • Organomegaly:
    • Liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver
    • Spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen
    • Heart
    • Tongue Tongue The tongue, on the other hand, is a complex muscular structure that permits tasting and facilitates the process of mastication and communication. The blood supply of the tongue originates from the external carotid artery, and the innervation is through cranial nerves. Oral Cavity: Lips and Tongue
  • Obstructive airway disease:
    • Thick mucus
    • Enlarged tonsils
    • Noisy breathing
    • Frequent respiratory infections
  • Tendency to develop abdominal and inguinal hernias

MPS II

  • Attenuated cases are less severe but are not designated as distinct entities.
  • Disease progression:
    • Symptom onset between ages 2 and 4 years
    • Frequently, death by age 15 years (usually cardiopulmonary complications)
    • Patients with attenuated cases may live into their 50s.
  • Similar clinical features as for MPS I but milder presentation
  • Distinguishing characteristics:
    • Absence of corneal clouding
    • Aggressive behavioral tendencies
    • Communicating hydrocephalus
    • Chronic diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
    • White lesions on limbs and trunk

MPS III

  • Disease progression:
    • Symptom onset after 1st year of life
    • Marked decline in learning between ages 2 and 6 years
    • Life expectancy variable Variable Variables represent information about something that can change. The design of the measurement scales, or of the methods for obtaining information, will determine the data gathered and the characteristics of that data. As a result, a variable can be qualitative or quantitative, and may be further classified into subgroups. Types of Variables, from late teens to early 30s
  • There are few clinical differences among the 4 clinical entities.
  • Similar clinical features as for MPS I
  • Distinguishing characteristics: severe neurologic symptoms
    • Progressive dementia
    • Aggressive behavior
    • Hyperactivity
    • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
    • Deafness
    • Vision loss
    • Insomnia Insomnia Insomnia is a sleep disorder characterized by difficulty in the initiation, maintenance, and consolidation of sleep, leading to impairment of function. Patients may exhibit symptoms such as difficulty falling asleep, disrupted sleep, trouble going back to sleep, early awakenings, and feeling tired upon waking. Insomnia
    • Progressive unsteadiness on feet
    • Unable to walk by age of 10 years

MPS IV

  • Disease progression:
    • Symptom onset between ages 1 and 3 years
    • Physical growth slows and often stops around age 8 years.
    • Life expectancy to 20s or 30s, unless the severe form is present
  • Similar clinical features as for MPS I
  • Presentations are similar in both types, but appear more severe in MPS IVA.
  • Distinguishing characteristics:
    • Progressive skeletal changes, particularly in the ribs and chest
      • Bell-shaped chest
      • Flattening or curvature of the spine
      • Shortened long bones
      • Dysplasia of the hips, knees, ankles, and wrists
      • Odontoid hypoplasia (cervico-occipital malformation that can be fatal)
    • Spinal nerve and nerve root compression
    • Intelligence is normal (unless hydrocephalus is present).
Dysmorphic features in mps

Clinical features of mucopolysaccharidosis IIIA:
Facial dysmorphism (coarse facial features, slightly depressed nasal bridge, prominent eyebrows, low-set ears, malocclusion, full cheeks, wiry and dry hair, and short neck) and skeletal symptoms (genu valga, varus feet, and stocky hands) are shown.

Image: “Dysmorphic features of our patient” by Department of Paediatrics, Medical University of Lublin, Racławickie 1, 20-059, Lublin, Poland. License: CC BY 4.0

MPS VI

  • Disease progression:
    • Normal growth and development to age 8 years
    • Development of truncal shortening, crouched stance, and joint restriction by age 10 years
    • Life expectancy variable Variable Variables represent information about something that can change. The design of the measurement scales, or of the methods for obtaining information, will determine the data gathered and the characteristics of that data. As a result, a variable can be qualitative or quantitative, and may be further classified into subgroups. Types of Variables: late teens and 20s
  • Similar clinical features as for MPS I, but commonly with normal intellectual development
  • Distinguishing characteristics:
    • Neurologic complications include: 
      • Clouded corneas
      • Deafness
      • Thickening of the dura → nerve root compression → pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain 
    • Truncal shortening
    • Crouched stance (forward-curving spine)
    • Joint restriction
    • Cardiac valve disorders
    • Pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension (PH) or pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure, which can lead to chronic progressive right heart failure. Pulmonary hypertension is grouped into 5 categories based on etiology, which include primary PAH, and PH due to cardiac disease, lung or hypoxic disease, chronic thromboembolic disease, and multifactorial or unclear etiologies. Pulmonary Hypertension
Mucopolysaccharidosis vi

Rapidly progressing MPS VI in a 16-year-old patient:
Face shows coarse facies, with frontal bossing, enlarged tongue, thick lips Lips The lips are the soft and movable most external parts of the oral cavity. The blood supply of the lips originates from the external carotid artery, and the innervation is through cranial nerves. Oral Cavity: Lips and Tongue, abnormal dentition, and gingival hyperplasia.

Image: “Rapidly progressing 16-year old MPS VI patient” by Reference Center for Inherited Metabolic Diseases, Necker-Enfants Malades Hospital, Paris, France. License: CC BY 2.0

MPS VII

  • Disease progression:
    • Rarest form; causes children to be born with hydrops fetalis:
      • Widespread fluid retention
      • Leads to infantile death
    • Most children are less severely affected:
      • Mild to moderate intellectual impairment by age 3 years
      • Life expectancy to teens or 20s
  • Similar clinical features as for MPS I
  • Distinguishing characteristics:
    • Susceptibility to pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia
    • Communicating hydrocephalus

MPS IX

  • Nodular soft tissue masses located around joints
  • Episodes of painful swelling of the joint masses
  • Mild facial changes
  • Short stature (as seen in other MPS disorders)
  • Normal joint movement
  • Normal intelligence

Diagnosis

Clinical history and examination:

  • Family history
  • Recognition of typical deformities in infants and young children

Laboratory analysis:

  • Urine GAG concentrations 
  • Enzyme assays to confirm the specific enzyme deficiency: 
    • Serum testing in suspected cases in infancy or early childhood
    • Prenatal diagnosis can be performed with the use of amniocentesis and chorionic villus sampling. 
  • Genetic testing

Management

There is no cure for MPS. Medical care is aimed at treating systemic conditions and at improving quality of life.

  • Genetic counseling for parents who have a family history of MPS to determine if they are carrying a causative genetic mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations
  • Physical therapy to delay joint problems and improve mobility 
  • Surgery:
    • Correction of obstructive airway disorders and sleep Sleep Sleep is a reversible phase of diminished responsiveness, motor activity, and metabolism. This process is a complex and dynamic phenomenon, occurring in 4-5 cycles a night, and generally divided into non-rapid eye movement (NREM) sleep and REM sleep stages. Physiology of Sleep apnea
    • Correction of hernias
    • CSF drainage
    • Nerve/nerve root decompression
    • Corneal transplantation.  
  • Enzyme replacement therapies:
    • Currently in use for:
      • MPS I
      • MPS II
      • MPS IVA
      • MPS VI 
      • Enzyme replacement for other types is in development.
    • Therapy has proven useful in reducing:
      • Nonneurologic symptoms
      • Pain
  • Bone marrow Bone marrow Bone marrow, the primary site of hematopoiesis, is found in the cavities of cancellous bones and the medullary canals of long bones. There are 2 types: red marrow (hematopoietic with abundant blood cells) and yellow marrow (predominantly filled with adipocytes). Composition of Bone Marrow transplantation (BMT) and umbilical cord blood transplantation (UCBT):
    • Limited success in treating MPSs
    • High-risk procedures usually performed only after extensive evaluation and parental counseling

Differential Diagnosis

  • Mucolipidosis: lysosomal storage disease Lysosomal storage disease Lysosomal storage diseases are a group of metabolic disorders caused by genetic mutations in the enzymes responsible for normal lysosomal function. The dysfunction of enzymatic processes causes an accumulation of undigested metabolites, resulting in cellular death. The main groups include sphingolipidoses, oligosaccharidoses, and mucolipidoses. Overview of Lysosomal Storage Diseases with excessive storage of lipids. Children with mucolipidosis may share some clinical features associated with the MPSs (facial features, bony/structural abnormalities, brain abnormalities). Diagnosis is made with laboratory testing to demonstrate enzyme deficiency. Management is supportive.
  • Gaucher disease Gaucher disease Gaucher Disease (GD) is an autosomal recessive lysosomal storage disorder caused by a deficiency of glucocerebrosidase enzyme activity, resulting in accumulation of glucocerebroside in cells and certain organs. The disease is categorized into 3 types with variable clinical presentation. Gaucher Disease: most common lysosomal storage disorder; results from glucocerebrosidase deficiency. The 3 types have varying presentations and severity. These presentations can include hepatosplenomegaly, thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia, easy bruising, bone fractures, and progressive neurologic deterioration. The diagnosis is made with DNA DNA The molecule DNA is the repository of heritable genetic information. In humans, DNA is contained in 23 chromosome pairs within the nucleus. The molecule provides the basic template for replication of genetic information, RNA transcription, and protein biosynthesis to promote cellular function and survival. DNA Types and Structure or enzyme analysis. Management depends on the type and includes enzyme replacement, splenectomy, glucosylceramide inhibitors, and bone marrow or stem cell transplantation. 
  • Tay-Sachs disease Tay-Sachs disease Tay-Sachs disease is an autosomal recessive lysosomal storage disorder caused by genetic mutations in the hexosaminidase A (HEXA) gene, leading to progressive neurodegeneration. Classic symptoms in infants include rapid degeneration of cognitive and neuromuscular abilities, progressive blindness, and a macular cherry-red spot on physical examination. Tay-Sachs Disease: lysosomal storage disorder resulting from hexosaminidase A deficiency. The 3 types have variable Variable Variables represent information about something that can change. The design of the measurement scales, or of the methods for obtaining information, will determine the data gathered and the characteristics of that data. As a result, a variable can be qualitative or quantitative, and may be further classified into subgroups. Types of Variables onsets. Patients may present with macular cherry-red spots, blindness, deafness, cognitive and motor deterioration, dysphagia Dysphagia Dysphagia is the subjective sensation of difficulty swallowing. Symptoms can range from a complete inability to swallow, to the sensation of solids or liquids becoming "stuck." Dysphagia is classified as either oropharyngeal or esophageal, with esophageal dysphagia having 2 sub-types: functional and mechanical. Dysphagia, dysarthria, spasticity, ataxia, seizures, and psychosis. The diagnosis is made with enzyme activity testing and molecular analysis. Management is supportive.
  • Niemann-Pick disease Niemann-Pick disease Niemann-Pick disease (NPD) is a rare, inherited, lysosomal storage disorder. The disease is classified on the basis of the genetic mutation. Type A and type B result from mutations in the SMPD-1 gene, resulting in acid sphingomyelinase enzyme deficiency. Type C results from NPC1 or NPC2 gene mutations, which are needed for intracellular transport of lipids. Niemann-Pick Disease (NPD): rare inherited, lysosomal storage disorder that is classified based on the genetic mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations. Types A and B NPD result in acid sphingomyelinase enzyme deficiency. Clinical manifestations may include failure to thrive Failure to Thrive Failure to thrive (FTT), or faltering growth, describes suboptimal weight gain and growth in children. The majority of cases are due to inadequate caloric intake; however, genetic, infectious, and oncological etiologies are also common. Failure to Thrive, hepatosplenomegaly, thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia, interstitial lung disease, cognitive and motor impairment, and macular cherry-red spots. The diagnosis can be confirmed by the measurement of sphingomyelinase activity or biomarkers, genetic testing, or biopsy. Management is supportive.

References

  1. Mucopolysaccharidoses Face Sheet. (n.d.). National Institute of Neurological Disorders and Stroke. Retrieved May 22, 2021, from https://web.archive.org/web/20160818205908/http://www.ninds.nih.gov/disorders/mucopolysaccharidoses/detail_mucopolysaccharidoses.htm
  2. Sihoun, H. (2021). Mucopolysaccharidoses: clinical features and diagnosis. Retrieved May 22, 2021, from https://www.uptodate.com/contents/mucopolysaccharidoses-clinical-features-and-diagnosis
  3. Sihoun, H. (2021). Mucopolysaccharidoses: treatment. Retrieved May 22, 2021, from https://www.uptodate.com/contents/mucopolysaccharidoses-treatment
  4. Sihoun, H. (2021). Mucopolysaccharidoses: complications. Retrieved May 22, 2021, from https://www.uptodate.com/contents/mucopolysaccharidoses-complications

Learn even more with Lecturio:

Complement your med school studies with Lecturio’s all-in-one study companion, delivered with evidence-based learning strategies.

Study on the Go

Lecturio Medical complements your studies with evidence-based learning strategies, video lectures, quiz questions, and more – all combined in one easy-to-use resource.

¡Hola!

Esta página está disponible en Español.

🍪 Lecturio is using cookies to improve your user experience. By continuing use of our service you agree upon our Data Privacy Statement.

Details