Diagnostic challenges in Salla disease

Jessica N. Hartley, Michael S. Salman, Frances A. Booth, Lorne Seargeant, David A. Wenger, Jens Wrogemann, Aizeddin A. Mhanni

Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Canada Program of Genetics and Metabolism, Winnipeg, Canada.
Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Canada Program of Genetics and Metabolism, Winnipeg, Canada Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada.
Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada Diagnostic Services Manitoba, University of Manitoba, Winnipeg, Canada.
Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada Section of Pediatric Neurology, University of Manitoba, Winnipeg, Canada.
Department of Radiology, Section of Pediatric Radiology, University of Manitoba, Winnipeg, Canada.
Lysosomal Diseases Testing Laboratory, Thomas Jefferson University, Philadelphia, USA.

DOI: 10.4236/ojgen.2013.32A3007                

Abstract

Sialic acid storage disease (Salla disease) is an autosomal recessive disorder caused by mutations in a lysosomal sialic acid export protein, SLC17A5 (OMIM #604369). This disorder was initially described in Northern Finland but more recently has been reported in patients of other ethnicities. We describe the clinical presentation and the neuroimaging findings of two non-Finnish children where a diagnosis of Salla disease was suspected on the basis of brain magnetic resonance imaging. The biochemical confirmation of this diagnosis posed a challenge as both patients had elevated percent free urine sialic acid but biochemical analyses in fibroblasts were not conclusive; therefore, molecular testing was necessary for confirmation of the diagnosis. The described encounters demonstrate the importance of pursuing confirmatory molecular diagnostic testing when a sialic acid storage disorder is suspected.

Keywords

Sialic Acid; Salla Disease; Lysosomal;SLC17A5

Conflicts of Interest

The authors declare no conflicts of interest.

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