Epilepsy: ALG13-Related Early Infantile Epileptic Encephalopathy via the ALG13 Gene
Summary and Pricing 
Test Method
Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture ProbesTest Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
---|---|---|---|---|---|
7355 | ALG13 | 81479 | 81479,81479 | $990 | Order Options and Pricing |
Pricing Comments
This test is also offered via our exome backbone with CNV detection (click here). The exome-based test may be higher priced, but permits reflex to the entire exome or to any other set of clinically relevant genes.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
Testing run on PG-Select capture probes does not include exome-wide CNV analysis. Reflex is available to PGxome or an exome-based panel, or you can use this gene list to create a custom panel (click here).
Click here for costs to reflex to whole PGxome.
Turnaround Time
3 weeks on average for standard orders or 2 weeks on average for STAT orders.
Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.
Targeted Testing
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
Clinical Features and Genetics 
Clinical Features
Early Infantile Epileptic Encephalopathy (EIEE) is a clinically and genetically heterogeneous neurodevelopmental disorder. The key feature of EIEE is onset of frequent and/or severe seizures within the first few weeks of life (Noh et al. 2012. PubMed ID: 22342633).
ALG13-related early infantile epileptic encephalopathy is a rare genetic cause for early infantile epilepsy. Major symptoms of this disorder include intractable seizures, severe cognitive impairment, developmental regression after onset of seizures, and hypotonia. Some patients present hydrocephalus, pyramidal and extrapyramidal signs. Initial EEG shows Hypsarrhythmia and Multifocal discharges, while MRI presents structural brain abnormalities including cerebral atrophy and delayed myelination. Patients could be diagnosed as having Lennox-Gastaut syndrome or West syndrome (Allen et al. 2013. PubMed ID: 23934111; Kobayashi et al. 2016. PubMed ID: 26482601).
Pathogenic variants in ALG13 are also associated with congenital disorder of glycosylation type I (CDG-I) (Timal et al. 2012. PubMed ID: 22492991).
A de novo common pathogenic variant c.320A>G in the ALG13 gene has been repeatedly reported in females with epileptic encephalopathy. However, male patients with either inherited or de novo pathogenic variant in the gene show a different phenotype, congenital disorder of glycosylation type I (Timal et al. 2012. PubMed ID: 22492991; Gadomski et al. 2017. PubMed ID: 28777499).
Genetics
ALG13-related early infantile epileptic encephalopathy is inherited in an X-linked dominant manner. It is caused by pathogenic variants in the ALG13 gene encoding a subunit of the uridine diphosphate-N-acetylglucosamine transferase. ALG13 is the soluble subunit recruited by membrane-bound ALG14 to form the heterodimeric ALG13/ALG14 complex catalyzing the formation of GlcNAc2-PP-dolichol, the second step in the synthesis of the lipid-linked oligosaccharides precursor for N-glycan assembly (Allen et al. 2013. PubMed ID: 23934111; Timal et al. 2012. PubMed ID: 22492991).
Reported pathogenic variants in ALG13 are missense only. No large deletions/duplications involving the ALG13 locus have been reported yet (Human Gene Mutation Database). De novo pathogenic variants in ALG13 have been reported (Allen et al. 2013. PubMed ID: 23934111).
Clinical Sensitivity - Sequencing with CNV PG-Select
In study of severe early infantile Epileptic Encephalopathy, less than 1% (2 in 264) of cases were found to be caused by de novo pathogenic variants in ALG13 (Allen et al. 2013. PubMed ID: 23934111).
To date, no large deletions/duplications involving ALG13 have been reported.
Testing Strategy
This test provides full coverage of all coding exons of the ALG13 gene, except for the region noted below, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.
Indications for Test
The test is recommended for patients suspected to have ALG13-related early infantile epileptic encephalopathy.
The test is recommended for patients suspected to have ALG13-related early infantile epileptic encephalopathy.
Gene
Official Gene Symbol | OMIM ID |
---|---|
ALG13 | 300776 |
Inheritance | Abbreviation |
---|---|
Autosomal Dominant | AD |
Autosomal Recessive | AR |
X-Linked | XL |
Mitochondrial | MT |
Disease
Name | Inheritance | OMIM ID |
---|---|---|
Epileptic Encephalopathy, Early Infantile, 36 | XL | 300884 |
Citations 
Ordering/Specimens 
Ordering Options
We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.
myPrevent - Online Ordering
- The test can be added to your online orders in the Summary and Pricing section.
- Once the test has been added log in to myPrevent to fill out an online requisition form.
- PGnome sequencing panels can be ordered via the myPrevent portal only at this time.
Requisition Form
- A completed requisition form must accompany all specimens.
- Billing information along with specimen and shipping instructions are within the requisition form.
- All testing must be ordered by a qualified healthcare provider.
For Requisition Forms, visit our Forms page
Specimen Types
Specimen Requirements and Shipping Details
ORDER OPTIONS
View Ordering Instructions1) Select Test Type
2) Select Additional Test Options
STAT and Prenatal Test Options are not available with Patient Plus.
No Additional Test Options are available for this test.