Kabuki Syndrome 2: KDM6A Sequencing

Turnaround Time

6 weeks

CPT Code(s)

81479

Cost

$1,500

Genes

• Kabuki syndrome 2

Kabuki syndrome is characterized by distinctive facial features, mild to moderate intellectual disability, postnatal growth deficiency, finger tip pads, and skeletal abnormalities, such as brachydactyly and vertebral defects. Characteristic facial features include long palpebral fissures with eversion of the lower lateral eyelid, depressed nasal tip, and high-arched eyebrows. Other features associated with Kabuki syndrome include cleft palate, congenital heart defects, and early breast development in females. KDM6A-related Kabuki syndrome is inherited in an X-linked, dominant pattern.

Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Sanger Sequencing

Mutations in the KDM6A gene may account for around 10% of patients with a clinical diagnosis of Kabuki syndrome who are negative for sequence variants in KMT2D.

The preferred sample type is 3-5 ml of peripheral blood collected in an EDTA (purple top) tube. Extracted DNA, dried blood spots, and saliva are also accepted for this test. Saliva samples must be submitted in an approved saliva kit. Contact the lab to receive a saliva kit or to have one sent to your patient.

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.