Sialic Acid

About NANS-CDG: is a congenital disorder of glycosylation caused by biallelic genetic variants in NANS, encoding an essential enzyme in de novo sialic acid synthesis. Sialic acid at the end of glycoconjugates plays a key role in biological processes such as brain and skeletal development.

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What is Sialic Acid? 

Sialic acids are the sugars at the end of sugar chains that sit on the surface of cells. They are important because they act as the ID card of that particular cell inside our body. (You can learn more about sialic acid HERE).

How can sialic acid help people living with GNE-CDG? 

The GNE gene has information to make a protein that is essential for the production of sialic acid inside our cells. Read the interesting overview that the National Human Genome Research Institute dedicates to GNE Myopathy here. 

This CDG is characterized by a progressive muscle weakness due to defects in the GNE gene that is crucial for the production of a diverse family of sugars - the sialic acids. Thus, you may find that this condition is referred to as neuromuscular or CDG. Watch the video below to learn about what is GNE Myopathy.

Oral sialic acid was administered in GNE-CDG mice and patients with good results. However, sialic acid is rapidly eliminated from the body (in urine). Therefore, other compounds that are more stable and last longer inside the body, such as sialic acid-extended release (SA-ER) are being studied. SA-ER stabilized muscle strength of the arms and hands of GNE-CDG patients. 

Publications in CDG are constantly growing. We  have selected articles of special interest for you, see below. Not all are open access, thus if you wish to  access the full information, please contact us at https://worldcdg.org/contact

• CDG Therapies: From Bench to Bedside

ProDGNE is a collaborative effort combining patient experience, complementary, and synergist expertise in glycobiology, biochemistry, medicinal chemistry, clinical pharmacology, -omics, biomarker discovery, pharmaceutical technology and clinical expertise to develop proof of principle of novel attractive compounds to treat GNE Myopathy (GNEM) and bring lead compounds one step closer to patients. Learn more here. 

How can sialic acid help people living with NANS-CDG?

The production of sialic acid involves different proteins working together in an assembly line. The NANS gene has the information for one of those proteins (called CMP-N-acetylneuraminic acid synthetase). Sialic acid was studied in a  NANS-CDG animal model (a small fish called zebrafish) and it was able to recover the skeletal manifestations. A clinical trial (ClinicalTrials.gov NCT03545568) involving 10 patients was done to study the effect of sialic acid supplementation. 

No results have been published yet. Sialic acid supplementation was also administered while the baby was still in the womb (started during the third trimester of pregnancy) and it was well tolerated by the mother (you can know more about the results of this publication NANS-CDG: Delineation of the Genetic, Biochemical, and Clinical Spectrum. A publication with the results of this trial is going to be published in the future. 

Publications in CDG are constantly growing. We  have selected articles of special interest for you, see below. Not all are open access, thus if you wish to  access the full information, please contact us at https://worldcdg.org/contact

• NANS-CDG: Delineation of the Genetic, Biochemical, and Clinical Spectrum
• NANS-mediated synthesis of sialic acid is required for brain and skeletal development