Test Directory

Clear All
Test Code
6PAH
Test Name
Phenylketonuria Carrier Screening
CPT Codes
81406
Clinical Utility
Genetic analysis to provide a molecular diagnosis of this disorder. Recommended for individuals with a personal and/or family history of this disorder to ensure appropriate treatment and establish recurrence risk for family members.
Specimen and Container Info

Preferred/Alternate

Specimen Type

Containers

Volume

Preferred Specimen Type

Whole Blood

Lavender Top (EDTA)

3 mL

Alternate Specimen Type

Genomic DNA

1.5 mL Tube

3 µg (at a concentration of at least 30 ng/µl), preferably in TE solution.


NOTE: For specimens from outside of North America, the preferred specimen type is Genomic DNA. HNL Genomics does not recommend shipping whole blood or cultured cells from any location other than the United States, Canada, or Mexico.
Transport Instructions
  • Transport at room temperature within 24 hours.
  • If the specimen cannot be transported to the lab within 24 hours, refrigerate for up to 72 hours.
  • Do not freeze or expose to extreme temperatures, refrigerate for up to 72 hours if cannot be transported to lab within 24 hours. 
Stability Requirements

Room Temperature

24 hours

Refrigerated

72 hours
Causes for Rejection
  • Improperly labeled specimen (minimum of two patient identifiers)
  • Inappropriate specimen type
  • Incomplete or incorrect test request form
  • Insufficient volume
  • Specimen has leaked in transit
  • Specimen without a test order
Methodology
Next Generation Sequencing and Copy Number Variation Analysis
Performing Location
Genomics - Snowdrift
Description

This test is designed to detect carriers of phenylketonuria. Phenylketonuria (PKU) is an autosomal recessive disorder resulting from faulty metabolism of the amino acid, phenylalanine. In individuals with untreated PKU, dietary intake of phenylalanine can lead to profound intellectual disability, behavioral issues, epilepsy, hypopigmentation, and a musty body odor. Additionally, women with PKU are at risk for having children with various birth defects due to exposure of the baby to high phenylalanine levels from maternal plasma. Newborn screening and early initiation of treatment, including lifelong dietary restriction of phenylalanine, can significantly improve disease prognosis. PKU (MIM 261600) is caused by pathogenic variants in the PAH gene (NM_000277). Individuals with a heterozygous pathogenic PAH variant are carriers for PKU and are at risk of having a child with this disorder. If both reproductive partners are PKU carriers, the risk for PKU in their children is 25%. The prevalence of PKU varies in different populations and is more common in individuals of Turkish, Irish, northern European, and East Asian ancestry. This test is intended for pre/post-conception carrier screening and is not intended for diagnostic testing.
Testing Schedule
Monday-Friday
Genes
PAH
MIM
261600
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
© 2024 HNL Lab Medicine. All rights reserved.