Mucolipidosis I

Sialidosis is a rare lysosomal storage disease with two distinct clinical phenotypes. Type I sialadosis is the milder form with onset of gait abnormalities, progressive vision loss, bilateral macular cherry-red spots, and myoclonus in the second or third decade. Ataxia and seizures have also been reported in type I patients. Type II has an earlier onset with coarse facial features, dysostosis multiplex, short stature, developmental delay, mental retardation and hepatosplenomegaly. Type II patients may also present with a congenital-onset form associated with ascites and hydrops fetalis prenatally, an infantile-onset form with the absence of symptoms at birth or a juvenile form that has onset in late childhood and a relatively milder phenotype. Seizures, myoclonus and renal involvement have also been documented in type II cases. The frequency of diagnosed sialidosis in the general population is estimated at approximately one in four million live births.

Tests Available

Forms and Documents

Test Details

  • Confirmation of a biochemical diagnosis
  • Carrier testing
  • Prenatal diagnosis in at risk pregnancy


4 weeks
2-5 mL Blood - Lavender Top Tube
Buccal Swabs

*Reporting times are typical, but could be extended in situations outside GeneDx's reasonable control.


  • 272.2 Mixed hyperlipidemia, Broad- or floating-betalipoproteinemia, Combined hyperlipidemia, Elevated cholesterol with elevated triglycerides NEC, Fredrickson Type IIb or III hyperlipoproteinemia, Hypercholesterolemia with endogenous hyperglyceridemia, Hyperbetalipoproteinemia with prebetalipoproteinemia, Tubo-eruptive xanthoma Xanthoma tuberosum
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**The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.


  1. Caciotti et al., (2009) J Neurol 256:1911-1915.
  2. Bonten et al., (2000) Hum Mol Genet 9:2715-2725.
  3. Coutinho et al., (2012) Clin Genet 2012) Clin Genet 81:379-393.
  4. Pattison et al., (2004) Hum Mutat 23:32-39.
  5. Seyrantepe et al., (2003) Hum Mutat 22:343-352.