Sign in →

Test Code TBX5 Seq TBX5 Sequencing

Clinical System Name

TBX5 Sequencing


Holt-Oram Syndrome


Holt-Oram syndrome (HOS) is characterized by:

  1. Upper-extremity malformations involving radial, thenar, or carpal bones;
  2. A personal and/or family history of congenital heart malformation, most commonly ostium secundum atrial septal defect (ASD) and ventricular septal defect (VSD), especially those occurring in the muscular trabeculated septum; and/or
  3. Cardiac conduction disease.

An abnormal carpal bone is present in all affected individuals and may be the only evidence of disease. Seventy-five percent of individuals with HOS have a congenital heart malformation.  More than 70% of individuals who meet strict diagnostic criteria have an identifiable mutation in TBX5.


Sample Requirements

Specimen: Whole Blood

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

Preferred Vol: 3 - 5 mL

Minimum Vol: 1 mL for small infants



Specimen: DNA

Container(s): Sterile plastic tube

Preferred Vol: 15 µg of purified DNA at a concentration of at least 20 µg/ml 

Minimum Vol:

Processing Instructions

Reject due to:

Spin: N

Aliquot: N

Temp: 2-8 C

Storage location: Deliver blood to Sendouts refrigerator rack


Off-site collection: Send whole blood refrigerated.


Specimen Type Temperature Time
Whole blood Room temp 2 d
Whole blood Refrigerated 7 d
Whole blood Frozen N
Extracted DNA Room temp 3-4 d
Extracted DNA Refrigerated 1 y
Extracted DNA Frozen Indefinitely



N 3-4 w


Performing Laboratory



Department:     PreventionGenetics, 3800 S. Business Park Ave., Marshfield, Wisconsin 54449

Phone Number:    (715) 387-0484

Reference Range

Interpretive report is provided.


Method: This test involves bidirectional sequencing using genomic DNA of all coding exons of the TBX5 gene plus ~20 bp of flanking non-coding DNA on each side.

Analytical Volume:


CPT Codes

81405       (updated 5/4/2016 by sstasi) 

Special Instructions

Links to:



Clinical Utility

Candidates for this test are patients showing features consistent with HOS (evaluated via echocardiography, ECG, and hand x-rays) and family members of patients who have known TBX5 mutations.


GeneReviews: Holt-Oram syndrome


Genetics Home Reference: Holt-Oram syndrome

Send Out Instructions

Reference Test Name: Holt-Oram Syndrome (HOS) via the TBX5 Gene
Reference Test Number: 785
Instructions: Ship whole blood overnight, ambient temperature. PreventionGenetics accepts Saturday delivery