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Laboratory Test Directory

IDUA Gene Sequencing

Components

Name Method Department Units
IDUA Gene Sequencing Sanger sequencing
Analysis of the entire coding region: Sequence analysis
DNA extraction
Polymerase chain reaction (PCR)
Molecular Genetics

Specimen Requirements

Whole blood

Container Type Container Size Specimen Volume
Preferred

Purple tube (EDTA)

4 mL 2 mL-4 mL
Stability

Room temperature - 24 hour(s)
Refrigerated - 72 hour(s)

Specimen Preparation

  • Do not freeze
  • Do not centrifuge

Reasons for Rejection

  • Wrong collection tube
  • Wrong type of specimen
  • Delayed or improper handling
  • Frozen specimen
  • Clotted specimen

Comments

Please click on the Lab Form link in the Forms setcion to print and complete the Genetic Test Requisition Form. Submission of completed Genetic Test Requisition Form is required, and submission of informed consent form is recommended (but not required). Please send any available clinical information with Requisition Form.

This test is a full gene sequence analysis of the IDUA gene that sequences the entire protein coding regions (exons) as well as splice sites (exon-intron junctions).

Presence of a pathogenic variant in both alleles of the IDUA gene is known to cause mucopolysaccharidosis type I (MPS I). MPS I is an autosomal recessive, progressive genetic disorder that can cause a widely variable disease severity that are classified into two groups - Severe MPS I (also known as Hurler syndrome) and Attenuated MPS I (also known as Hurler-Scheie syndrome or Scheie syndrome). Individuals with severe MPS I typically start manifesting symptoms within the first year of life, which those with attenuated MPS I typically develop symptoms between ages 3 to 10 years. Common clinical features of MPS I include coarse facial features, recurrent upper respiratory and ear infections early in life, inguinal or umbilical hernia, hepatosplenomegaly, gibbus deformity, limited joint range of motion, and corneal clouding. Individuals with MPS I have deficient activity of the lysosomal enzyme alpha-L-iduronidase, which can be detected in most tissue types including blood leukocytes, plasma, or cultured fibroblasts. Diagnosis of MPS I can be made by detecting presence of biallelic pathogenic variants in the IDUA gene by molecular genetic testing and/or detection of deficient alpha-L-iduronidase enzyme activity by enzyme activity testing.

Targeted mutation analysis is available for family members when familial mutation is known (see Test Code: FMLIS).

Forms

Lab Form

CPT Code

  • 81406