This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objective: We aimed to decipher the molecular genetic basis of disease in a cohort of children with a uniform clinical presentation of neonatal irritability, spastic or dystonic quadriplegia, virtually absent psychomotor development, axonal neuropathy, and elevated blood/CSF lactate.
Methods: We performed whole-exome sequencing of blood DNA from the index patients. Detected compound heterozygous mutations were confirmed by Sanger sequencing. Structural predictions and a bacterial activity assay were performed to evaluate the functional consequences of the mutations. Mass spectrometry, Western blotting, and protein oxidation detection were used to analyze the effects of selenoprotein deficiency.
Results: Neuropathology indicated laminar necrosis and severe loss of myelin, with neuron loss and astrogliosis. In 3 families, we identified a missense (p.Thr325Ser) and a nonsense (p.Tyr429*) mutation in SEPSECS, encoding the O-phosphoseryl-tRNA:selenocysteinyl-tRNA synthase, which was previously associated with progressive cerebellocerebral atrophy. We show that the mutations do not completely abolish the activity of SEPSECS, but lead to decreased selenoprotein levels, with demonstrated increase in oxidative protein damage in the patient brain.
Conclusions: These results extend the phenotypes caused by defective selenocysteine biosynthesis, and suggest SEPSECS as a candidate gene for progressive encephalopathies with lactate elevation.
GLOSSARY
- PCH2D=
- pontocerebellar hypoplasia type 2D;
- PEHO=
- progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy;
- RC=
- respiratory chain;
- SRM-MS=
- selected reaction monitoring–mass spectrometry;
- T4=
- thyroxine;
- tRNA=
- transfer RNA;
- TSH=
- thyroid-stimulating hormone;
- T3=
- triiodothyronine
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
↵* These authors contributed equally to this work.
Supplemental data at Neurology.org
- Received November 17, 2014.
- Accepted in final form March 26, 2015.
- © 2015 American Academy of Neurology
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Letters: Rapid online correspondence
REQUIREMENTS
You must ensure that your Disclosures have been updated within the previous six months. Please go to our Submission Site to add or update your Disclosure information.
Your co-authors must send a completed Publishing Agreement Form to Neurology Staff (not necessary for the lead/corresponding author as the form below will suffice) before you upload your comment.
If you are responding to a comment that was written about an article you originally authored:
You (and co-authors) do not need to fill out forms or check disclosures as author forms are still valid
and apply to letter.
Submission specifications:
- Submissions must be < 200 words with < 5 references. Reference 1 must be the article on which you are commenting.
- Submissions should not have more than 5 authors. (Exception: original author replies can include all original authors of the article)
- Submit only on articles published within 6 months of issue date.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- Submitted comments are subject to editing and editor review prior to posting.
You May Also be Interested in
More Online
Association of Neurofilament Light With the Development and Severity of Parkinson Disease
Dr. Rodolfo Savica and Dr. Parichita Choudhury