The Latest MacTel Research: What does it mean for patients?

Scientists at the Lowy Medical Research Institute and their collaborators recently published an article describing a role for serine and toxic lipids in macular telangiectasia type 2.  The article, “Serine and Lipid Metabolism in Macular Disease and Peripheral Neuropathy,” was published online by the New England Journal of Medicine on September 11, 2019.1

The findings at a glance:

A genetic variation in a few MacTel patients leads to toxic lipids in the body:

Researchers discovered that people who have the rare peripheral neuropathy, hereditary and sensory autonomic neuropathy (HSAN1), often also have MacTel;

Patients with the genetic variations that cause HSAN1 have high levels of toxic lipids called deoxysphingolipids;

Most MacTel patients do not have HSAN1.


Low serine levels in MacTel patients are correlated/associated with high levels of toxic lipids in the body:

Low serine levels can lead to a build-up of these same toxic lipids (deoxysphingolipids);

Many MacTel patients have low serine levels – this was found in a previously published study;2

When MacTel patient blood was tested, low serine levels correlated with high levels of this toxic lipid.


Toxic lipids cause MacTel and peripheral neuropathy:

Toxic lipids (deoxysphingolipids) accumulate when serine is low or because of a genetic variation;

These lipids can cause the peripheral neuropathy HSAN1. They can also cause MacTel.


The findings in this paper describe an association between low serine and high toxic lipid levels in MacTel.  While this is an important step forward as LMRI researchers and their collaborators work towards finding new treatments for MacTel, there are insufficient data at this time to recommend a therapy based on this study. More work needs to be done to translate these findings to patients.


What does this research mean for people diagnosed with MacTel?

Should MacTel patients get their serine levels measured?

Serine has not been measured in enough people to define “normal” serine levels in the population.  This study demonstrated that persons affected with MacTel had lower levels of serine than the controls used in this study.

Therefore, there is no need to ask your health care provider to have a serine level drawn. Additionally, this test may only be available at specific specialty laboratories.

Will serine supplements help MacTel patients?

There is no data to date that serine supplementation may prevent, slow the progression of, or have any other effect on MacTel Type 2.

Therefore, at this time the authors cannot recommend for or against the use of serine supplementation.

Does the MacTel Project screen for peripheral neuropathy (PN)?  

Peripheral neuropathy participants in this study were previously diagnosed with a neurological disease (HSAN1). They were screened for MacTel to find out if deoxysphingolipids play a role in MacTel.  The MacTel Project does not screen for, nor diagnose, any specific diseases based on the genetic samples that persons enrolled in the MacTel Registry provided.  Researchers are doing more work to find out how often MacTel patients are also diagnosed with peripheral neuropathy.

If you have a peripheral neuropathy or symptoms of PN (numbness, tingling, pain, ulcers or abnormal temperature or sensory sensations) in your extremities and are concerned, please contact and follow up with your health care provider.

If you are already enrolled in the MacTel Registry and have questions or are interested in enrolling, please contact your study team or LMRI at



  1. L. Gantner, K. Eade, M. Wallace, et al. Serine and Lipid Metabolism in Macular Disease and Peripheral Neuropathy. New England Journal of Medicine. Published online September 11, 2019 at
  2. S. Scerri, et al. Genome-wide analyses identify common variants associated with macular telangiectasia type 2. Nature Genetics 49, 559-567 (2017).