Ordering Recommendation

Confirm diagnosis of inherited insulin resistance syndrome in individuals with clinical and/or biochemical evidence. For initial testing or to rule out inherited insulin resistance syndrome, refer to Insulin, Fasting (0070063) or Fasting Glucose, Plasma or Serum (0020024).

Mnemonic
INSR FGS
Methodology

Polymerase Chain Reaction/Sequencing

Performed

Varies

Reported

14-21 days

New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval
Interpretive Data

Background Information for Inherited Insulin Resistance Syndromes (INSR) Sequencing:
Characteristics:
  Extreme insulin resistance is characterized by abnormal glucose homeostasis and hyperinsulinemia, leading eventually to ketoacidosis. Donohue syndrome (leprechaunism), Rabson-Mendenhall syndrome, and Type A insulin resistance are all caused by INSR gene mutations, although severity and survival varies greatly among syndromes. Symptoms may include intrauterine growth restriction, failure to thrive after birth, characteristic dysmorphic features, lack of subcutaneous fat, acanthosis nigricans, enlargement of genitalia in males and females, cystic ovaries and amenorrhea in females, premature and dysplastic dentition, and pineal hyperplasia.
Incidence: Unknown; rare.
Inheritance: Autosomal recessive (Donohue and Rabson-Mendenhall syndromes). Type A insulin resistance can be autosomal recessive or dominant.
Cause: Pathogenic INSR gene mutations.
Clinical Sensitivity: Predicted to be greater than 90 percent in individuals with a clinical diagnosis.
Methodology: Bidirectional sequencing of the entire coding region and intron/exon boundaries of the INSR gene.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected.  Mutations in genes other than INSR are not evaluated.

Counseling and informed consent are recommended for genetic testing.  Consent forms are available online at www.aruplab.com.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
CPT Codes

81479

Components
Component Test Code* Component Chart Name LOINC
2006275 INSR Sequencing Specimen
2006276 INSR Sequencing Interpretation
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • INSR Sequencing assay
Inherited Insulin Resistance Syndromes (INSR) Sequencing