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Test Catalog

Test ID: OLIGU    
Oligosaccharide Screen, Random, Urine

Useful For Suggests clinical disorders or settings where the test may be helpful

Screening for selected oligosaccharidosis

Genetics Test Information Provides information that may help with selection of the correct genetic test or proper submission of the test request

Oligosaccharidoses are characterized by the abnormal accumulation of incompletely degraded oligosaccharides in cells and tissues and the corresponding increase of related free oligosaccharides in the urine.

 

Clinical features of oligosaccharidoses often overlap; therefore, urine screening is an important tool in the initial workup for these disorders.

 

Enzyme or molecular analysis is required to make a definitive diagnosis.

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Oligosaccharide analysis may be considered in the workup of unexplained refractory epilepsy. For more information see Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm in Special Instructions.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The oligosaccharidoses (glycoproteinoses) are a subset of lysosomal storage disorders (LSD) caused by the deficiency of any one of the lysosomal enzymes involved in the degradation of complex oligosaccharide chains. They are characterized by the abnormal accumulation of incompletely degraded oligosaccharides in cells and tissues and the corresponding increase of related free oligosaccharides in the urine. Clinical diagnosis can be difficult due to the similarity of clinical features across disorders and their variable severity. Clinical features can include bone abnormalities, coarse facial features, corneal cloudiness, organomegaly, muscle weakness, hypotonia, developmental delay, and ataxia. Age of onset ranges from early infancy to adult and can even present prenatally.

 

The oligosaccharidoses and other storage disorders detected by this assay include alpha-mannosidosis, beta-mannosidosis, aspartylglucosaminuria, fucosidosis, Schindler disease, GM1 gangliosidosis, Sandhoff disease, sialidosis, galactosialidosis, mucolipidoses types II and III, mucopolysaccharidosis IVA (Morquio A), mucopolysaccharidosis IVB (Morquio B), and Pompe disease (see table). Additional conditions that may be picked up by this test include other mucopolysaccharidoses, Gaucher disease, Krabbe disease, and some congenital disorders of glycosylation (PMM2, NGLY1, MOGS, ALG1, MAN1B1).

 

Conditions identifiable by method

Disorder

Onset

Gene

Enzyme deficiency

Worldwide incidence

Alpha-mannosidosis

Prenatal (type III) Infancy (type I) Juvenile/Adult (type II)

MAN2B1

Alpha-mannosidase

1:500,000

Phenotype: continuum of clinical features ranging from severe and rapidly progressive disease to a milder and more slowly progressive course. Prenatal onset (type III) manifests as prenatal loss or early death from progressive neurodegeneration. Infantile onset (type I) is characterized by rapidly progressive mental retardation, hepatosplenomegaly, and severe dysostosis multiplex. Type II is milder and slower progressing with survival into adulthood.

Beta-mannosidosis

Infancy to juvenile

MANBA

Beta-mannosidase

<100 patients described

 

Phenotype: clinical features vary in severity and may include intellectual disability, respiratory infections, hearing loss, hypotonia, peripheral neuropathy, and behavioral issues.

Aspartylglucosaminuria

Early childhood

AGA

Aspartylglucosaminidase

1:2,000,000 higher incidence in Finland approx 1:17,000

Phenotype: normal appearing at birth followed by progressive neurodegeneration at 2-4 years, frequent respiratory infections, coarse features, thick calvarium, and osteoporosis. Slowly progressive mental decline into adulthood.

Alpha-fucosidosis

Infancy to early childhood

FUCA1

Alpha-fucosidase

<100 patients described

Phenotype: continuum within a wide spectrum of severity; clinical features include neurodegeneration, coarse facial features, growth delay, recurrent infections, dysostosis multiplex, angiokeratoma, and elevated sweat chloride.

Schindler disease

Infancy (type I)

 

Early childhood (type III)

Adult (type II)

NAGA

Alpha-N-acetyl-galactosaminidase

<30 patients described

Phenotype: continuum of clinical features ranging from severe and rapidly progressive disease to a milder and more slowly progressive course; infantile onset (type I) is characterized by rapidly progressive neurodegeneration. Type II is adult onset characterized by angiokeratoma and mild cognitive impairment, and type III is an intermediate and variable form ranging from seizures and psychomotor delay to milder autistic features.

GM1 gangliosidosis

Infancy (type I)

 

Late infantile/juvenile (type II)

Adult (type III)

GLB1

Beta-galactosidase (Beta-Gal)

1:200,000

Phenotype: continuum of clinical features ranging from severe and rapidly progressive disease to a milder and more slowly progressive course; infantile onset (type I) is characterized by early developmental delay/arrest followed by progressive neurodegeneration, skeletal dysplasia, facial coarseness, hepatosplenomegaly, and macular cherry red spot. Later onset forms (types II and III) are milder and observed as progressive neurologic disease and vertebral dysplasia. Adult onset presents mainly with dystonia.

GM2 gangliosidosis variant 0

(Sandhoff disease)

Early infancy to juvenile or adult

HEXB

Beta-hexosaminidase A and B

1:400,000

Phenotype: infantile onset is characterized by rapidly progressive neurodegeneration, exaggerated startle reflex, "cherry red spot". Milder later-adult onset forms of the disease exist presenting with neurological problems such as ataxia, dystonia, spinocerebellar degeneration, and behavior changes.

Sialidosis (ML I)

Early adulthood (type I)

Earlier for congenital, infantile, and juvenile forms (type II)

NEU1

Alpha-neuraminidase (Neu)

<30 patients described

Phenotype: continuum of clinical features ranging from severe disease (type II) to a milder and more slowly progressive course (type I). Clinical features range from early developmental delay, coarse facial features, short stature, dysostosis multiplex, and hepatosplenomegaly to late onset cherry-red spot myoclonus syndrome. Seizures, hyperreflexia, and ataxia have been reported in more than 50% of later onset patients. A congenital form of the disease has been reported in which patients present with fetal hydrops or neonatal ascites.

Galactosialidosis

Early infancy, late infancy or early adult

CTSA

Cathepsin A causing secondary deficiencies in Beta-Gal and Neu

<30 patients described

Phenotype: continuum of clinical features ranging from severe and rapidly progressive disease to a milder and more slowly progressive course; clinical features of the early infantile type include fetal hydrops, edema, ascites, visceromegaly, dysostosis multiplex, coarse facies, and cherry red spot. The majority of patients have milder presentations, which include ataxia, myoclonus, angiokeratoma, cognitive and neurologic decline.

Mucolipidosis II-alpha/-beta (I-cell)

Mucolipidosis III-alpha/-beta and III-gamma (pseudo-Hurler Polydystrophy)

Early infancy

 

Early childhood, may live well into adulthood 

GNPTAB(alpha/beta)

GNPTG (gamma)

N-acetylglucosaminyl-1-phosphotransferase deficiency causing secondary intracellular deficiency of multiple enzyme activities

1:300,000

Phenotype: I-cell resembles Hurler with short stature and skeletal anomalies, but presents earlier, is more severe, and can include cardiomyopathy and coronary artery disease. Pseudo-Hurler polydystrophy is milder and later presenting.

Mucopolysaccharidosis IVB (Morquio B)

Infancy to adult

GLB1

Beta-Gal

1:75,000

N. Ireland

1:640,000

W. Australia

Phenotype: progressive condition that largely affects the skeletal system. Features include short-trunk dwarfism, skeletal (spondyloepiphyseal) dysplasia, fine corneal deposits, and preservation of intelligence.

Pompe disease (glycogen storage disease type II)

Early infancy

Late onset (childhood-adult)

GAA

Alpha-glucosidase

1:40,000

Phenotype: infantile onset is characterized by prominent cardiomegaly, hepatomegaly, hypotonia, and weakness. Later onset forms present with proximal muscle weakness and respiratory insufficiency.

 

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation Provides information to assist in interpretation of the test results

This is a screening test; not all oligosaccharidoses are detected. The resulting excretion profile may be characteristic of a specific disorder; however, abnormal results require confirmation by enzyme assay or molecular genetic testing.

 

When abnormal results are detected with characteristic patterns, a detailed interpretation is given, including an overview of results and significance, a correlation to available clinical information, elements of differential diagnosis, recommendations for additional confirmatory studies (enzyme assay, molecular genetic analysis).

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test may give false-negative results, especially in older patients with mild clinical presentations.

 

This test may give false-positive results for Pompe disease, especially in pediatric patients on infant formula.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Neufeld EF, Muenzer J. The mucopolysaccharidoses. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2020. Accessed May 01, 2020. Available at: http://ommbid.mhmedical.com/content.aspx?bookid=2709&sectionid=225544161

2. Enns GM, Steiner RD, Cowan TM: Lysosomal disorders. In: Sarafoglou K, Hoffmann GF, Roth KS eds. Pediatric Endocrinology and Inborn Errors of Metabolism. McGraw Hill Medical; 2009

Special Instructions Library of PDFs including pertinent information and forms related to the test