FRAGILE X SYNDROME DNA TESTING

Mnemonic

FRAGX

Guidelines

Use to diagnose Fragile X syndrome in individuals with characteristic clinical symptoms or a positive family history and to determine carrier status in females.

Specimen Collection Requirements

Collect

Whole Blood, one lavender (EDTA) or yellow (ACD solution A or B) top tube

Handling

Store at room temperature unless storage will exceed 48 hours then store refrigerated.

Preferred Volume

5.0 mL

Minimum Volume

1.5 mL

Transport

Room temperature unless more than 48 hours then refrigerated

Rejection Criteria

Hemolyzed or frozen samples

Stability

Ambient: 1 week; Refrigerated: 1 month; Frozen: 6 months

Testing Information

Performed

7 days/week

Reported

6-16 days

Method

Polymerase Chain Reaction/Capillary Electrophoresis

Referral Lab

ARUP (2009033)

Reference Values

Reference Values

Interpretation provided.

Comments

It is recommended that high-resolution chromosome studies be performed concomitantly with Fragile X testing.  A significant number of patients being tested for Fragile X have a chromosome abnormality in addition to/or instead of Fragile X.  High-resolution studies, however, do not rule out Fragile X.  Refer to Chromosomal Analysis Peripheral Blood for specimen requirements.

CPT Codes

81243; if reflexed add 81244

Last Updated: Thursday, January 5, 2017 03:42:12 AM