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Steroid-Resistant Nephrotic Syndrome (SRNS) via the AVIL Gene

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
13303 AVIL 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
13303AVIL81479 81479,81479 $890 Order Options and Pricing

An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.

Click here for costs to reflex to whole PGxome (if original test is on PGxome Sequencing backbone).

Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing backbone).

Turnaround Time

18 days on average for standard orders or 13 days 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.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Wuyan Chen, PhD

Clinical Features and Genetics

Clinical Features

Nephrotic syndrome (NS) is a genetically heterogeneous disease defined by proteinuria, hypoalbuminemia, hyperlipidemia, and edema (Benoit et al. 2010. PubMed ID: 20333530; Santín et al. 2011. PubMed ID: 21415313; Preston et al. 2019. PubMed ID: 29181713). It is the most common glomerular disease in children. Nephrotic syndrome in young adults and children is classified into steroid-sensitive NS (SSNS) versus steroid-resistant NS (SRNS) in terms of its response to standardized steroid therapy. Approximately 20% of cases are SRNS, characterized by resistance to steroid treatment and rapid progression to end-stage renal failure. The prevalent histological feature of SRNS is focal segmental glomerulosclerosis (FSGS), which has been seen in approximately 60% of SRNS cases. Hereditary FSGS can be either limited to the kidney or syndromic with features in other systems. Diffuse mesangial sclerosis (DMS) is the other important histological feature associated with SRNS. SRNS accounts for ~11% of early-onset chronic kidney disease (Vivante and Hildebrandt. 2016. PubMed ID: 26750453). The clinical courses of NS vary greatly with a wide range of age at onset from birth to adulthood. A conclusive molecular diagnosis is necessary for better personalized treatment and accurate genetic counselling.

Extrarenal manifestations in patients with SRNS caused by defects in the AVIL gene have been reported to include retinal dystrophy, deafness, cataract, microcephaly, intellectual disability, and short stature (Rao et al. 2017. PubMed ID: 29058690). However, it is uncertain that these features are common for AVIL-related SRNS due to limited cases.

Genetics

Steroid-resistant nephrotic syndrome (SRNS) represents a clinically and genetically heterogeneous group of autosomal dominant, autosomal recessive or X-linked disorders. The AVIL gene falls into the group of autosomal recessive inheritance and is one of the minor causative genes for the disease (Rao et al. 2017. PubMed ID: 29058690).

Loss-of-function is the underlying mechanism of AVIL for SRNS. This gene encodes the actin-binding protein advillin that is involved in podocyte cytoskeleton architecture. To date, only three missense and one truncating variant have been reported (Human Gene Mutation Database; Rao et al. 2017. PubMed ID: 29058690). Large deletions and duplications have not been reported in this gene. De novo variants are presumably rare.

AVIL has been cited as a nonessential gene for growth of human tissue culture cells (Online Gene Essentiality, ogee.medgenius.info). To date, no animal models have been reported (Rao et al. 2017. PubMed ID: 29058690).  

Clinical Sensitivity - Sequencing with CNV PGxome

In a cohort of approximately 800 individuals with SRNS worldwide, two unrelated patients (~0.25%) were reported to have compound heterozygous pathogenic variants in the AVIL gene (Rao et al. 2017. PubMed ID: 29058690).

Testing Strategy

This test is performed using Next-Gen sequencing with additional Sanger sequencing as necessary.

This test provides full coverage of all coding exons of the AVIL gene plus 10 bases of flanking noncoding DNA in all available transcripts along with other non-coding regions in which pathogenic variants have been identified at PreventionGenetics or reported elsewhere. We define full coverage as >20X NGS reads or Sanger sequencing. PGnome panels typically provide slightly increased coverage over the PGxome equivalent. PGnome sequencing panels have the added benefit of additional analysis and reporting of deep intronic regions (where applicable).

Dependent on the sequencing backbone selected for this testing, discounted reflex testing to any other similar backbone-based test is available (i.e., PGxome panel to whole PGxome; PGnome panel to whole PGnome).

Indications for Test

Candidates for this test are patients with steroid-resistant nephrotic syndrome (SRNS). Targeted testing is indicated for family members of patients who have known pathogenic variants in the AVIL gene. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in AVIL.

Gene

Official Gene Symbol OMIM ID
AVIL 613397
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Nephrotic syndrome, type 21 AR 618594

Citations

  • Benoit et al. 2010. PubMed ID: 20333530
  • Human Gene Mutation Database (Biobase).
  • Online Gene Essentiality (OGEE).
  • Preston et al. 2017. PubMed ID: 29181713
  • Rao et al. 2017. PubMed ID: 29058690
  • Santín et al. 2011. PubMed ID: 21415313
  • Vivante and Hildebrandt. 2016. PubMed ID: 26750453

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

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

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ORDER OPTIONS

View Ordering Instructions

1) Select Test Method (Backbone)


1) 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.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
Total Price: $
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