Metabolic defect: sialic acid transporter deficiency Other transport/trafficking diseases: cystinosis | mucolipidosis IV | Salla

Current page: Infantile sialic acid storage disease Select Another Disease Select disease Acid sphingomyel. def. Aspartylglycosaminuria Cystinosis Fabry disease Farber disease Fucosidosis type I Fucosidosis type II Galactosialidosis Gaucher type I Gaucher type II Gaucher type III GM1 gangliosidosis I GM1 gangliosidosis II GM1 gangliosidosis III Infantile sialic acid Krabbé disease Mannosidosis Metachr. leukodys. I Metachr. leukodys. II Metachr. leukodys. III MPS I MPS II Hunter MPS III Sanfilippo MPS IV Morquio MPS VI Maroteaux-Lamy MPS VII Sly Mucolipidosis II Mucolipidosis III Mucolipidosis IV Neuro ceroid lipof I Neuro ceroid lipof II Neuro ceroid lipof III Neuro ceroid lipof IV Pompe disease Pycnodysostosis Salla disease Sandhoff type I Sialidosis type I Sialidosis type II Tay-Sachs type I Tay-Sachs type II Tay-Sachs type III

Caused by defective transport of free sialic acid across the lysosomal membrane, leading to accumulation of sialic acid in tissue and excretion of free sialic acid in the urine.

Ataxia		Ataxia		Strabismus

ISSD is the most severe of the free sialic acid storage disorders, characterized by multi-systemtic involvement, including hydrops fetalis, with death usually occurring in early childhood.[1] All patients show evidence of mental retardation. Severely affected patients usually present within the first 8 months of life with developmental delay followed by slowly progressive neurologic disorder that includes seizures, ataxia, and nystagmus.^[2] Symptoms may also include coarse facial features, hepatosplenomegaly, and cardiomegaly.^[1]

Failure to thrive

Developmental delay

Hypotonia

Ataxia

Seizures

Coarse facial features

Anteverted nose

Gum hypertrophy

High-arched palate

Mild rib widening

Osteopenia

J-shaped sella

Metaphyseal irregularities

Calcaneal calcifications

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Clear cornea

Epicanthal folds

Ptosis

Nystagmus

Cardiomegaly

Heart failure

Ascites

Hepatomegaly

Splenomegaly

Nephrotic syndrome

Hypopigmented skin

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1. Kleta, Robert; Gahl, William. Update July 2003. www.genetests.org/servlet/access?db=geneclinics&site=gt&id=8888891&key=JLbfNEYK5i029&gry=&fcn=y&fw=VUbi&filename=/profiles/issd/index.html. Accessed July 2004.

2. National Center for Biotechnology Information; OMIM, Online Mendelian Inheritance in Man. www.nlm.nih.gov/cgi/jablonski/syndrome_cgi?index=571 Accessed July 2004.

4. Meikle PJ, Hopwood JJ, Clague AE, Carey WF. Prevalence of Lysosomal Storage Disorders. JAMA. 1999; 281: 249-254.

5. National Center for Biotechnology Information; OMIM, Online Mendelian Inheritance in Mam. www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=269920 Accessed July 2004.