sialuria; sialic acid storage disorder; N-acetylneuraminic acid storage disease; Salla disease

Pathology: 1) free sialic acid accumulates in the cytoplasm 2) gram quantities of neuraminic acid are secreted in urine 3) metabolic defect involves lack of feedback inhibition of UDP-GlcNAc 2-epimerase by CMP-Neu5Ac, resulting in constitutive overproduction of free Neu5Ac 4) enlarged lysosomes are seen on electron microscopic studies Genetics: 1) associated in defects of gene for SLC17A5 autosomal recessive 2) associated in defects of gene for GNE (autosomal dominant) Clinical manifestations: 1) developmental delay 2) coarse facial features 3) hepatomegaly 4) hypotonia 5) cerebellar ataxia 6) mental retardation 7) symptoms generally present < 1 year of age 8) progression is slow 9) infantile sialuria is associated with non-immune hydrops fetalis Laboratory: 1) gram quantities of neuraminic acid are found in urine 2) SLC17A5 gene mutation

Related

bifunctional UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase; UDP-GlcNAc-2-epimerase/manAc kinase; includes: UDP-N-acetylglucosamine 2-epimerase; UDP-GlcNAc-2-epimerase; uridine diphosphate-N-acetylglucosamine-2-epimerase; N-acetylmannosamine kinase; manAc kinase (GNE, GLCNE) sialic acid; N-acetyl neuraminic acid (NANA) solute carrier family 17 member 5 (SLC17A5, sialin, Na+/sialic acid cotransporter, sodium phosphate cotransporter, AST, membrane glycoprotein HP59)

References

OMIM :accession 269920, 604369