3-Methylglutaconic Aciduria Type I via the AUH 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
11827 AUH 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
11827AUH81479 81479 $890 Order Options and Pricing

Pricing Comments

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.

A 25% additional charge will be applied to STAT orders. View STAT turnaround times here.

For Reflex to PGxome pricing click here.

The Sanger Sequencing method for this test is NY State approved.

For Sanger Sequencing click here.

Targeted Testing

For ordering sequencing of targeted known variants, go to our Targeted Variants page.

Turnaround Time

18 days on average

EMAIL CONTACTS

Genetic Counselors

Geneticist

Clinical Features and Genetics

Clinical Features

3-methylglutaconic aciduria type I (MGA1) is a rare disorder resulting from deficiency of 3-methylglutaconyl-CoA hydratase, a mitochondrial enzyme that catalyzes the fifth step of leucine catabolism. Accumulation of toxic leucine metabolites results in mainly a neurologic condition, although clinical severity varies widely. The first two patients with molecular confirmation of 3-methylglutaconyl-CoA hydratase deficiency were children reported to have motor and speech delays in one case and only speech delay in the other (IJlst et al. 2002). Among five other MGA1 patients from four families (Ly et al. 2003), speech and motor delays were the most common findings. Remarkably, one individual in this cohort had deficiency of 3-methylglutaconyl-CoA hydratase resulting from a homozygous null mutation in the AUH gene, but was completely asymptomatic at the age of 2 years. Another confirmed patient presented with febrile seizures from the age of 1 year, but had no speech or motor delay (Illsinger et al. 2004). An adult-onset patient with progressive forgetfulness, unsteady gait, hyperreflexia in all four limbs, cerebellar ataxia, dysarthria, and urinary incontinence has also been reported (Eriguchi et al. 2006). Gait disturbance and incontinence presented when the patient was in her 50’s. She was also found to have impaired cognitive function. Wortmann et al. reported optic atrophy in one of his patients who was genetically confirmed to have 3-MGS-uria Type 1 (Wortmann et al. 2010). Mercimek-Mahmutoglu reported two siblings with phenotypic heterogeneity (2011). The older sister was diagnosed at 10 years old with a learning disability and attention deficit, while the younger brother had febrile seizures early in childhood and was diagnosed with an expressive language delay and severe delay in speech sound development at 3 years of age.

Genetics

3-methylglutaconic aciduria type I is an autosomal recessive disorder caused by pathogenic variants in the AUH gene. This gene is located on chr 9q22 and encodes the 3-methylglutaconyl-CoA hydratase protein. Based on the small number of reported cases, null mutations that abolish enzyme activity are the most common form of pathogenic variants (Human Gene Mutation Database). Complete absence of 3-methylglutaconyl-CoA hydratase may be compatible with normal development (Ly et al. 2003; Wortmann et al. 2012).

Testing Strategy

This test provides full coverage of all coding exons of the AUH 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).

Clinical Sensitivity - Sequencing with CNV PGxome

At this time, the sensitivity of this test is difficult to estimate due to the low number of cases reported in the literature. Analytical sensitivity may be high as the majority of reported causative variants are detectable by sequencing (Human Gene Mutation Database).

To date, only a single large deletion has been reported in the AUH gene (Mercimek-Mahmutoglu et al. 2011).

Indications for Test

Individuals with elevated urinary 3-methylglutaconic acid, 3-methylglutaric acid, and 3- hydroxyisovaleric acid and clinical signs of 3-methylglutaconic aciduria type I. Presence of urinary 3-hydroxyisovaleric acid is a specific finding for isolated 3-methylglutaconyl-CoA hydratase deficiency. Patients with symptoms suggestive of inherited optic neuropathy are also candidates. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in AUH.

Gene

Official Gene Symbol OMIM ID
AUH 600529
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
3-Methylglutaconic Aciduria AR 250950

Citations

  • Eriguchi M. et al. 2006. Neurology. 67: 1895-6. PubMed ID: 17130438
  • Human Gene Mutation Database (Bio-base).
  • IJlst L. et al. 2002. American Journal of Human Genetics. 71: 1463-6. PubMed ID: 12434311
  • Illsinger S. et al. 2004. Pediatric Neurology. 30: 213-5. PubMed ID: 15033206
  • Ly T.B. et al. 2003. Human Mutation. 21: 401-7. PubMed ID: 12655555
  • Mercimek-Mahmutoglu S. et al. 2011. Molecular Genetics and Metabolism. 104: 410-3. PubMed ID: 21840233
  • Wortmann S.B. et al. 2010. Neurology. 75: 1079-83. PubMed ID: 20855850
  • Wortmann S.B. et al. 2012. Journal of Inherited Metabolic Disease. 35: 13-22. PubMed ID: 20882351

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.

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

loading Loading... ×

ORDER OPTIONS

View Ordering Instructions

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.

Total Price: $
×
Copy Text to Clipboard
×