Maturity Onset Diabetes of Young (MODY) via the PDX1 Gene
Summary and Pricing
Test MethodExome Sequencing with CNV Detection
|Test Code||Test Copy Genes||Test CPT Code||Gene CPT Codes Copy CPT Codes||Base Price|
|9125||PDX1||81404||81404,81479||$890||Order Options and Pricing|
|Test Code||Test Copy Genes||Test CPT Code||Gene CPT Codes Copy CPT Code||Base Price|
|9125||PDX1||81404||81404, 81479||$890||Order Options and Pricing|
Our favored testing approach is exome based NextGen sequencing with CNV analysis. This will allow cost effective reflexing to PGxome or other exome based tests. However, if full gene Sanger sequencing is desired for STAT turnaround time, insurance, or other reasons, please see link below for Test Code, pricing, and turnaround time information. If the Sanger option is selected, CNV detection may be ordered through Test #600.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
The Sanger Sequencing method for this test is NY State approved.For Sanger Sequencing click here.
18 days on average for standard orders or 14 days on average for STAT orders.
Once a specimen has started the testing process in our lab, the most accurate prediction of TAT will be displayed in the myPrevent portal as an Estimated Report Date (ERD) range. We calculate the ERD for each specimen as testing progresses; therefore the ERD range may differ from our published average TAT. View more about turnaround times here.
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
Clinical Features and Genetics
Maturity onset diabetes of the young (MODY), a primary pancreatic beta-cell defect, is the most common type of monogenic diabetes, accounting for up to 5% of young adults diagnosed with diabetes (Owen 2013; McDonald et al. 2013). MODY typically presents in lean young adults before 25 years with an autosomal dominant family history. MODY patients have continued production of endogenous insulin, absence of beta-cell autoimmunity and absence of signs of insulin resistance. As this non-insulin dependent type of diabetes is frequently misdiagnosed as Type 1 or Type 2 diabetes, a timely and accurate molecular diagnosis of MODY is essential to treatment decisions, prognosis, family screening and obstetric management of gestational diabetes (Ellard et al. 2008). MODY has been conventionally classified into 11 types in terms of causative genes (Molven et al. 2011).
MODY is inherited in an autosomal dominant manner. Proteins encoded by MODY-associated genes include nuclear transcription factors controlling pancreatic development (HNF1A, HNF4A, HNF1B, PDX1, KLF11, PAX4 and NEUROD1), glucokinase (a glucose sensor in pancreatic beta-cells) (GCK), insulin (INS), kinase stimulating insulin synthesis and secretion (BLK), the enzyme carboxyl ester lipase (CEL), and the ATP-sensitive potassium (KATP) channels (ABCC8 and KCNJ11). The PDX1 gene (also known as IPF1; 2 coding exons) encodes a homeodomain-containing transcription factor, which plays a major role in glucose-dependent regulation of insulin gene expression. Recessive PDX1 mutations cause pancreatic agenesis leading to neonatal diabetes mellitus while dominant PDX1 mutations cause MODY4 (Stoffers et al. 1997). Causative genetic defects of PDX1 found so far include missense, nonsense mutations and small deletion/insertions (Human Gene Mutation Database). Exon-level large deletions involving PDX1 have not been reported.
Clinical Sensitivity - Sequencing with CNV PGxome
Over 80% of all known MODY cases in the UK are caused by mutations in HNF1A (~30%), HNF4A (~10%), GCK (~30%) and HNF1B (5-10%) (Owen 2013). In the UK, HNF1A-MODY is the most common form in adults while GCK-MODY is the most common form in children. For the remaining genes associated with rare forms of MODY including PDX1, the mutation detection rates in a large cohort of patients are unknown because these mutations were only reported in a limited number of patients (families).
This test provides full coverage of all coding exons of the PDX1 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.
Since this test is performed using exome capture probes, a reflex to any of our exome based tests is available (PGxome, PGxome Custom Panels).
Indications for Test
Candidates for this test are patients with MODY.
Candidates for this test are patients with MODY.
|Official Gene Symbol||OMIM ID|
- Ellard S. et al. 2008. Diabetologia. 51: 546-53. PubMed ID: 18297260
- Human Gene Mutation Database (Bio-base).
- McDonald T.J., Ellard S. 2013. Annals of Clinical Biochemistry. 50: 403-15. PubMed ID: 23878349
- Molven A., Njølstad PR. 2011. Expert Review of Molecular Diagnostics. 11: 313-20. PubMed ID: 21463240
- Owen KR. 2013. Clinical Medicine (London, England). 13: 278-81. PubMed ID: 23760703
- Stoffers DA, Zinkin NT, Stanojevic V, Clarke WL, Habener JF. 1997. Pancreatic agenesis attributable to a single nucleotide deletion in the human IPF1 gene coding sequence. Nat. Genet. 15: 106–110. PubMed ID: 8988180
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.
- 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.