X-Linked Opitz G/BBB syndrome : MID1 Sequencing

Test Information

MID1 sequencing is a molecular test used to identify variants in the gene associated with X-Linked Opitz G/BBB syndrome.

Turnaround Time

6 weeks

CPT Code(s)





Clinical Information

Males with X-linked Opitz G/BBB syndrome have multiple congenital anomalies such as genitourinary abnormalities, laryngo-tracheo-esophageal defects, cleft lip and/or palate, heart defects, anus anomalies, and midline brain defects. In addition, these individuals have a characteristic facial appearance and less than 50% will have developmental delay or intellectual disability. Female carriers often only manifest the ocular hypertelorism.


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


Sequencing of the MID1 gene will detect mutations in 15-50% of individuals with G/BBB syndrome.

Specimen Requirements

The preferred sample type is peripheral blood collected in an EDTA (purple top) tube – at least 2-3ml for pediatric patients and 5-6ml for adult patients. 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.

Transport Instructions

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 Testing Information

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.

Have Questions? Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Sanger Sequencing, Test Finder
Meet the Shenal Family

Meet the Shenal Family

Our daughter, Ryleigh, was diagnosed with a rare chromosomal deletion shortly after she was born in 2010. Since we received her diagnosis, the Greenwood Genetic Center has become part of our family. They made certain that we did not feel alone, and they continue to provide ongoing, compassionate care for our child. The impact they have had on our family and others across the globe everyday is immeasurable. We can't imagine walking this journey without their...

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