National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Aspartylglycosaminuria


Other Names:
Aspartylglucosaminuria; Aspartylglucosamidase (AGA) deficiency; AGU; Aspartylglucosaminuria; Aspartylglucosamidase (AGA) deficiency; AGU; AGA deficiency; Glycosylasparaginase deficiency See More
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Aspartylglycosaminuria is a very rare lysosomal storage disease that causes a progressive decline in mental functioning. Infants with aspartylglycosaminuria appear healthy at birth with signs and symptoms beginning around the age of 2 or 3. Major symptoms may include coarse facial features, spine and eye deformities, behavior problems, and intellectual disability.  Symptoms result from a deficiency in an enzyme called aspartylglycosaminidase, which leads to an accumulation of a protein called glycoasparagine in the body tissues and  increased excretion of this protein in the urine. Aspartylglycosaminuria is inherited in an autosomal recessive fashion and caused by mutations in the AGA gene. It is commonly seen in individuals of Finnish decent.[1][2][3]
Last updated: 8/17/2011
Infants with aspartylglycosaminuria appear healthy at birth, and development is typcailly normal throughout childhood. The first sign of this condition, which becomes evident around the age of 2 or 3, is usually delayed speech. Mild intellectual disability then becomes apparent, and learning occurs at a slowed pace. Intellectual disability progressively worsens in adolescence. Most people with this disorder lose much of the speech they have learned, and affected adults usually have only a few words in their vocabulary. Adults with aspartylglucosaminuria may develop seizures or problems with movement.[3]

People with this condition may also have bones that become progressively weak and prone to fracture (osteoporosis), an unusually large range of joint movement (hypermobility), and loose skin. Affected individuals tend to have a characteristic facial appearance that includes widely spaced eyes (ocular hypertelorism), small ears, and full lips. The nose is short and broad and the face is usually square-shaped. Children with this condition may be tall for their age, but lack of a growth spurt in puberty typically causes adults to be short. Affected children also tend to have frequent upper respiratory infections. Individuals with aspartylglucosaminuria usually survive into mid-adulthood.[3] The skeleton may also become deformed. The spine may be twisted (scoliosis) and the neck may be unusually short. The eyes may also develop cataracts. Behavior problems are common. Lung, heart and blood problems tend to occur in later years.[2]
Last updated: 8/17/2011

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormality of amino acid metabolism 0004337
Aspartylglucosaminuria
High urine aspartylglucosamine levels
0012068
Delayed speech and language development
Deficiency of speech development
Delayed language development
Delayed speech
Delayed speech acquisition
Delayed speech development
Impaired speech and language development
Impaired speech development
Language delay
Language delayed
Language development deficit
Late-onset speech development
Poor language development
Speech and language delay
Speech and language difficulties
Speech delay
[ more ] 		0000750
Dyskinesia
Disorder of involuntary muscle movements
0100660
Gingival overgrowth
Gum enlargement
0000212
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ] 		0000316
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Large face
Big face
0100729
Mandibular prognathia
Big lower jaw
Increased projection of lower jaw
Increased size of lower jaw
Large lower jaw
Prominent chin
Prominent lower jaw
[ more ] 		0000303
Microtia
Small ears
Underdeveloped ears
[ more ] 		0008551
Neurological speech impairment
Speech disorder
Speech impairment
Speech impediment
[ more ] 		0002167
Scoliosis 0002650
Short nose
Decreased length of nose
Shortened nose
[ more ] 		0003196
Thick vermilion border
Full lips
Increased volume of lip
Plump lips
Prominent lips
Thick lips
[ more ] 		0012471
Umbilical hernia 0001537
Wide nasal bridge
Broad nasal bridge
Broad nasal root
Broadened nasal bridge
Increased breadth of bridge of nose
Increased breadth of nasal bridge
Increased width of bridge of nose
Increased width of nasal bridge
Nasal bridge broad
Wide bridge of nose
Widened nasal bridge
[ more ] 		0000431
30%-79% of people have these symptoms
Abnormal cortical bone morphology 0003103
Abnormality of the ulna 0002997
Anterior beaking of lumbar vertebrae 0008430
Carious teeth
Dental cavities
Tooth cavities
Tooth decay
[ more ] 		0000670
Coarse facial features
Coarse facial appearance
0000280
Macroglossia
Abnormally large tongue
Increased size of tongue
Large tongue
[ more ] 		0000158
Macroorchidism
Large testis
0000053
Pectus carinatum
Pigeon chest
0000768
Thickened calvaria
Increased thickness of skull cap
Thickened skull cap
[ more ] 		0002684
5%-29% of people have these symptoms
Arthritis
Joint inflammation
0001369
Chronic otitis media
Chronic infections of the middle ear
0000389
Delayed skeletal maturation
Delayed bone maturation
Delayed skeletal development
[ more ] 		0002750
Hepatomegaly
Enlarged liver
0002240
Inguinal hernia 0000023
Joint stiffness
Stiff joint
Stiff joints
[ more ] 		0001387
Malabsorption
Intestinal malabsorption
0002024
Pes planus
Flat feet
Flat foot
[ more ] 		0001763
Recurrent respiratory infections
Frequent respiratory infections
Multiple respiratory infections
respiratory infections, recurrent
Susceptibility to respiratory infections
[ more ] 		0002205
Seizure 0001250
Sleep disturbance
Difficulty sleeping
Trouble sleeping
[ more ] 		0002360
Splenomegaly
Increased spleen size
0001744
Vascular skin abnormality 0011276
Percent of people who have these symptoms is not available through HPO
Abnormality of metabolism/homeostasis
Laboratory abnormality
Metabolism abnormality
[ more ] 		0001939
Acne 0001061
Angiokeratoma corporis diffusum 0001071
Anteverted nares
Nasal tip, upturned
Upturned nasal tip
Upturned nose
Upturned nostrils
[ more ] 		0000463
Autosomal recessive inheritance 0000007
Beaking of vertebral bodies 0004568
Brachycephaly
Short and broad skull
0000248
Broad face
Increased breadth of face
Increased width of face
Wide face
[ more ] 		0000283
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
Cerebral atrophy
Degeneration of cerebrum
0002059
Decreased prothrombin time 0032198
Depressed nasal bridge
Depressed bridge of nose
Flat bridge of nose
Flat nasal bridge
Flat, nasal bridge
Flattened nasal bridge
Low nasal bridge
Low nasal root
[ more ] 		0005280
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood
[ more ] 		0002376
Diarrhea
Watery stool
0002014
Dysostosis multiplex 0000943
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ] 		0001290
Hernia 0100790
Hoarse voice
Hoarseness
Husky voice
[ more ] 		0001609
Hypoplastic frontal sinuses 0002738
Joint laxity
Joint instability
Lax joints
Loose-jointedness
Loosejointedness
[ more ] 		0001388
Kyphosis
Hunched back
Round back
[ more ] 		0002808
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ] 		0000252
Mitral regurgitation 0001653
Muscular hypotonia
Low or weak muscle tone
0001252
Neutropenia
Low blood neutrophil count
Low neutrophil count
[ more ] 		0001875
Pathologic fracture
Spontaneous fracture
0002756
Platyspondyly
Flattened vertebrae
0000926
Short stature
Decreased body height
Small stature
[ more ] 		0004322
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
Spondylolisthesis
Displacement of one backbone compared to another
Slipped backbone
[ more ] 		0003302
Spondylolysis 0003304
Thick lower lip vermilion
Increased volume of lower lip
Plump lower lip
Prominent lower lip
[ more ] 		0000179
Vacuolated lymphocytes 0001922
Wide mouth
Broad mouth
Large mouth
[ more ] 		0000154
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Last updated: 7/1/2020
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.[3]
Last updated: 8/17/2011

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Aspartylglycosaminuria. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

  • The Lysosomal Disease Network is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with this condition through research. The Lysosomal Disease Network has a registry for patients who wish to be contacted about clinical research opportunities.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Aspartylglycosaminuria. Click on the link to view a sample search on this topic.

News

Other Conferences

  • 2012 International Conference for Glycoprotein Storage Diseases, July 27, 2012 - July 30, 2012
    Location: Crowne Plaza Hotel, Charleston, SC
    Description: The International Society for Mannosidosis & Related Storage Diseases (ISMRD) is sponsoring the 2012 International Conference for Glycoprotein Storage Diseases. The Scientific/Family meetings will be held concurrently on July 28th and 29th. Alongside this meeting, they are hosting the extension of the Natural History Study, with clinic days on July 27th and 30th.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • Both my brother and sister have aspartylglycosaminuria. I would like to get in contact with other families that have this illness. Also, can you provide some information on it? See answer


  1. Froissart R & Maire I. Aspartylglucosaminuria. Orphanet. February 2005; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=93. Accessed 8/17/2011.
  2. Aspartylglycosaminuria . National Organization for Rare Disorders (NORD). 2004; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/918/viewAbstract. Accessed 8/17/2011.
  3. Aspartylglucosaminuria. Genetics Home Reference. December 2008; http://ghr.nlm.nih.gov/condition/aspartylglucosaminuria. Accessed 8/17/2011.