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Alpha Globin (HBA1 and HBA2) Deletion/Duplication

Important Note

This test is under Utilization Management. All requests are reviewed and must be approved by a pathologist as part of the lab stewardship program.

Alpha Hemoglobin Common Deletions is recommended first tier test.

 

Clinical System Name

Miscellaneous Genetic Test

Synonyms

A globin

Alpha globin gene analysis

Alpha globin mutations

Alpha thalassemia

Sample Requirements

Specimen: Whole Blood

Container(s): Lavender/EDTA, Yellow/ACD

Preferred Vol: 3.0 mL

Minimum Vol: 1.0 mL

 

NOTE: Extracted DNA is NOT an accepted specimen type.

Processing Instructions

Reject due to:

Spin: N

Aliquot: N

Temp: 2 - 4 C

Storage Location: CPA 3 refrigerator, Send Outs rack.

 

Off-site Collection: Store and transport refrigerated.

Stability

Specimen Type Temperature Time
Whole Blood Room Temp 72 h
  Refrigerated 1 w
  Frozen Unacceptable

 

Availability

STAT Performed TAT
N Varies 14 d

 

Performing Laboratory

ARUP Laboratories

500 Chipeta Way
Salt Lake City, UT 84108-1221

 

Phone Number: (800) 522-2787

Department

Department: Send Outs/Genetics

Phone Number: (206) 987-2563

Methodology

Method: Multiplex Ligation-dependent Probe Amplification

Analytical Volume: 1.0 mL Whole Blood

Limitations:

Description

Alpha thalassemia is caused by decreased or absent synthesis of the hemoglobin alpha-chain resulting in variable clinical presentations. Alpha (+) thalassemia results from mutation of a single alpha2 globin gene (-a/aa) and is clinically asymptomatic (silent carrier). Alpha (0) thalassemia (trait) is caused by mutation of both alpha2 globin genes (-a/-a), or mutations in the alpha1 and alpha2 globin genes on the same chromosome, (--/aa) and results in mild microcytic anemia. Hemoglobin H disease occurs due to mutation of three alpha globin genes (--/-a) and results in hemolysis with Heinz bodies, moderate anemia, and splenomegaly. Hb Bart Hydrops Fetalis Syndrome results when mutations occur in all four alpha globin genes (--/--) and is lethal in the fetal or early neonatal period. Alpha globin gene triplications result in three active alpha globin genes on a single chromosome.

Reference Ranges

Interpretive report provided.

Send Out Instructions

Reference Test Name: Alpha Globin (HBA1 and HBA2) Deletion/Duplication
Reference Test Code: 2011622
Instructions: Send Monday through Friday with the ARUP courier.

 

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