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Branchio-Oto-Renal Syndrome: EYA1

Alternate test name

Brachiootorenal Spectrum Disorders, Melnick-Fraser Syndrome

Gene name / Alternate gene name
  • EYA1
  • BOR, BOP
Eyes absent homolog 1
Lab area
Genome Diagnostics - Molecular Genetics
Method and equipment
Deletion/duplication analysis via MLPA; Sequencing
Expected turn-around time
Prenatal samples: 2 weeks Pregnancy/STAT: 3-4 weeks Routine: 4-6 weeks
Specimen type

Blood; extracted DNA will not be accepted for the MLPA portion of this test.

For details about specimen requirements, please refer to: Specimen Type & Requirements (PDF).

Specimen requirements
  • Blood: 5-10 mL in EDTA, 0.5 mL in EDTA (neonate);
  • DNA-minimum 10 ug in 100 uL low TE (pH8.0) (sequencing only)

DNA extracted at an external lab is not accepted for MLPA testing.

Storage and transportation

Room Temperature

For details about specimen requirements, please refer to: Specimen Type and Requirements

Special requirements

Special Instructions for Genome Diagnostics Samples

If sample shipment >48 hours, ship on ice.

Shipping information
The Hospital for Sick Children
Division of Genome Diagnostics
555 University Avenue, Black Wing, Room 3416
Toronto, ON
M5G 1X8
Phone: 416-813-7200 ext. 2
Hours: Monday to Friday, 8 a.m. to 4:30 p.m.
Off hours: Please send to Rapid Response Laboratory, 555 University Avenue, Room 3642
Email Molecular Lab:
Email Cytogenetics:
Background and clinical significance

Branchio-oto-renal (BOR) syndrome is an autosomal dominant condition characterized by branchial, otic and renal anomalies. Branchial arch defects include cysts and fistulae. Otologic findings include sensorineural, conductive or mixed hearing loss with malformations of the outer, middle and inner ear. Renal malformations range from mild renal hypoplasia to bilateral renal agenesis, with some individuals progressing to end-stage renal disease later in life. Patients with BOR syndrome may show variability in clinical features due to incomplete penetrance and variable expressivity.

BOR syndrome is genetically heterogeneous; however, mutations in the EYA1 gene at 8q13.3 have been implicated in about 40 per cent of BOR syndrome cases. Of BOR syndrome patients with EYA1 mutations, approximately 75–80 per cent have point mutations in the EYA1 gene while the remainder may have rearrangements of the gene causing large deletions or insertions. Molecular testing for BOR syndrome consists of complete sequencing of the coding region and flanking exon/intron boundaries of the EYA1 gene to detect point mutations, and quantitative testing of the EYA1 gene to detect larger deletions or duplications.

BOR syndrome is present when an individual has one copy of the defective EYA1 gene. Affected individuals have a 50 per cent chance of transmitting the disorder to each child. There is a 50 per cent chance that the affected individual’s offspring will not be affected with BOR syndrome.

See related information sheet: Branchio-Oto-Renal Syndrome

Disease condition

Branchio-Oto-Renal Syndrome

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