GTP Cyclohydrolase I Deficiency

GTP Cyclohydrolase I (GTPCH1) deficiency is a disorder of the BH4 biosynthesis pathway, presenting with hyperphenylalaninemia (HPA) associated with monoamine neurotransmitter deficiency. Symptoms of this disorder include mental retardation, convulsions, tone and posture disturbances, drowsiness, irritability, abnormal movements, recurrent hyperthermia without infections, hypersalivation, and swallowing difficulties. The high levels of phenylalanine are often detected on newborn screening.

Tests Available

Forms and Documents

Test Info Sheet Test Requisition

Test Details

GCH1
  • Confirmation of a clinical diagnosis
  • Selection of appropriate treatment
  • Identification of at-risk family members
  • Capillary Sequencing

Ordering

230
3 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81405x1
Yes
Yes
  • 270.1 Phenylketonuria [PKU], Hyperphenylalaninemia
  • 781 Symptoms involving nervous and musculoskeletal systems Excludes: depression NOS (311) disorders specifically relating to: back (724.0-724.9) hearing (388.0-389.9) joint (718.0-719.9) limb (729.0-729.9) neck (723.0-723.9) vision (368.0-369.9) pain in limb (729.5)
* For price inquiries please email zebras@genedx.com

References

  1. Furukawa Y, (2009) Gene Reviews GTPCH1-Deficient DRD
  2. Clot F et Al., (2009) Brain 132: 1753-1763
  3. Thony B and Blau N, (2006) Hum Mutat 27:870- 878
  4. Zirn B et Al., (2008) J Neurol Neurosurg Psych 79:183-186
  5. Hagenah et Al., (2005) Neurology 64:908-911
  6. Muller U et Al., (2002) J Neural Transm 109:321-328
  7. Furukawa Y, (2004) Adv Neurol 94:127-138
  8. Furukawa Y et Al., (1998) Neurology 50:1015-20
  9. Furukawa Y et Al., (1998) Ann Neurol 44: 10-16
  10. Ichinose H et Al., (1994) Nat Genet 8:236-242
  11. Muller Y et Al., (1998) Neurogenetics 1:165-177
  12. Bandmann O et Al., (1996) Hum Molec Genet 5:403-406

Forms and Documents

Test Requisition Test Info Sheet

Test Details

GCH1
  • Confirmation of a clinical diagnosis
  • Selection of appropriate treatment
  • Identification of at-risk family members
  • Capillary Sequencing
  • Deletion/Duplication Analysis

Ordering

527
3 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81405x1, 81479x1
No
Yes
  • 270.1 Phenylketonuria [PKU], Hyperphenylalaninemia
  • 781 Symptoms involving nervous and musculoskeletal systems Excludes: depression NOS (311) disorders specifically relating to: back (724.0-724.9) hearing (388.0-389.9) joint (718.0-719.9) limb (729.0-729.9) neck (723.0-723.9) vision (368.0-369.9) pain in limb (729.5)
* For price inquiries please email zebras@genedx.com

References

  1. Muller Y et Al., (1998) Neurogenetics 1:165-177.
  2. Ichinose H et Al., (1994) Nat Genet 8:236-242.
  3. Bandmann O et Al., (1996) Hum Molec Genet 5:403-406.
  4. Furukawa Y et Al., (1998) Ann Neurol 44: 10-16.
  5. Furukawa Y et Al., (1998) Neurology 50:1015-20.
  6. Muller U et Al., (2002) J Neural Transm 109:321-328
  7. Furukawa Y, (2004) Adv Neurol 94:127-138.
  8. Hagenah et Al., (2005) Neurology 64:908-911.
  9. Thony B and Blau N, (2006) Hum Mutat 27:870- 878.
  10. Zirn B et Al., (2008) J Neurol Neurosurg Psych 79:183-186.
  11. Clot F et Al., (2009) Brain 132: 1753-1763.
  12. Furukawa Y, (2009) Gene Reviews GTPCH1-Deficient DRD.