Dopamine Beta-Hydroxylase Deficiency: DBH Sequencing
Alternate Name/ Synonym
- Norepinephrine Deficiency
- Noradrenaline Deficiency
Alternate Gene Name
External Proficiency Testing
Turn Around Time
2 weeks (Prenatal samples), 2-3 weeks (Pregnancy/Urgent samples), 4-6 weeks (Routine)
Dopamine beta-hydroxylase (Dopamine beta-monooxygenase)
Dopamine Beta-Hydroxylase Deficiency
Dopamine beta-Hydroxylase deficiency (DBHD) is a rare autosomal recessive form of primary autonomic failure characterized by a complete absence of noradrenaline and adrenaline in plasma together with increased dopamine plasma levels. DBH deficiency is mainly characterized by impaired exercise intolerance, severe orthostatic hypotension and persistent ptosis. These findings generally worsen in late adolescence and early adulthood.
DBHD is caused by a mutation in the DBH gene, located on chromosome 9 (9q34). Dopamine beta-hydroxylase is a copper-containg enzyme important in the synthesis of catecholamines, namely the conversion of dopamine to norepinephrine. Biochemical findings in individuals with DBHD include complete absence of plasma norepinephrine and epinephrine in conjunction with elevated plasma dopamine levels.
DBHD occurs when an individual receives two copies of a defective gene, one from each parent. Any person with one copy of the defective DBH gene is a carrier. Carriers do not have DBHD and will not develop the disease. However, if their partner is also a carrier, there is a one in four chance (25%) that their baby will be born with DBHD. There is a three in four chance (75%) that their baby will not have DBHD.
For details about specimen requirements, please refer to: Specimen Type & Requirements (PDF).
Minimum Specimen Requirements
5-10 mL EDTA or ACD 0.5 mL EDTA (neonate); minimum 10 ug in 100 uL low TE (pH8.0)
If sample shipment >48 hours, ship on ice.
Approval is not required
Shipping and Contact Information
The Hospital for Sick Children
Molecular Genetics Division
555 University Avenue
Room 3420, Hill Wing
Phone: 416-813-7200 ext. 1
Interpretation is provided in report
Information Sheet: Dopamine Beta-hydroxylase Deficiency
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