Test ID: THBNG    
THBD Gene, Next-Generation Sequencing, Varies

Ascertaining a pathogenic alteration in the THBD gene in patients with atypical hemolytic uremic syndrome

Ascertaining a pathogenic alteration in the THBD gene in patients with reduced thrombin generation and a strong family or personal history of excessive bleeding that is not explained by results of conventional and specialized coagulation testing

This test is not intended for prenatal diagnosis

This test detects alterations in the THBD gene, which have been associated with one of several clinical phenotypes and hereditary disorders, namely an increased risk for thrombosis, atypical hemolytic uremic syndrome (aHUS), and hereditary excessive bleeding following physical trauma or surgery. A genetic consultation is strongly recommended prior to ordering THBD sequencing.

The gene target for this test is:

Gene name (transcript): THBD (GRCh37 (hg19) NM_000361)

Chromosomal location: 20p11.21

No screening tests exist for defects in THBD.

If thrombotic tendency is a concern, a set of clinical guidelines from the British Society for Haematology on testing for heritable thrombophilia is freely available.(1)

If atypical hemolytic uremic syndrome (aHUS) is a concern, it is strongly recommended an etiological diagnosis of aHUS be attempted prior to genetic testing in order to focus on timely and informed treatment of the patient. Refer to the consensus statement on the identification and diagnosis of thrombotic microangiopathies by the Mayo Clinic Complement Alternative Pathway-Thrombotic Microangiopathy Disease-Oriented Group.(2) Additionally, a recommended list of laboratory investigations for patients identified as having aHUS has been developed by The European Paediatric Study Group.(3)

If a THBD-related bleeding disorder is a concern, this disorder has only been recently characterized and no algorithmic testing methodology has been developed that is specific to this disorder. A systematic diagnosis through conventional coagulation testing is recommended prior to considering genetic testing for any suspected bleeding disorder.

• Informed Consent for Genetic Testing
• Informed Consent for Genetic Testing (Spanish)
• Rare Coagulation Disorder Patient Information

Custom Sequence Capture and Targeted Next-Generation Sequencing (NGS) Followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing when Appropriate