Homocystinuria due to Cystathionine Beta-Synthase Deficiency

Homocystinuria due to cystathionine ß-synthase (CBS) deficiency is the most common inborn error of methionine metabolism, characterized by involvement of the eye (ectopia lentis and/or severe myopia), skeletal system (marfanoid habitus, osteoporosis, scoliosis, pectus excavatum, genu valgum), vascular system (premature atherosclerosis and thromboembolism), and central nervous system (developmental delay/mental retardation, seizures, psychiatric problems). Any or all of these systems may be involved. There is variable expressivity even among patients within the same family. Ectopia lentis may be the only presenting feature in some patients, other individuals can present with a thromboembolic event as an adult. About half of all CBS deficient patients respond to pharmacologic doses of pyridoxine (vitamin B6). Pyridoxine-responsiveness is constant within sibships. It has been estimated that newborn screening for elevated methionine levels detects only about one-third of patients.

Tests Available

Forms and Documents

Test Details

CBS
  • Confirmation of biochemical diagnosis
  • Carrier testing
  • Prenatal diagnosis in at risk pregnancies
  • Capillary Sequencing

Ordering

331
4-5 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81406x1
No
Yes
  • 270.45 Homocystinuria
* For price inquiries please email zebras@genedx.com

References

  1. Kraus et al., (1999) Hum Mutat 13:362-375
  2. Kruger et al., (2003) Hum Mutat 22:434-441
  3. Linnebank et al., (2004) Hum Mutat 24:352-353
  4. Urreizti et al., (2006) J Hum Genet 51:305-313
  5. Refsum et al., (2004) J Pediatr 144 :830-832

Forms and Documents

Test Details

ACTA2, ADAMTS2, ALDH18A1, ATP6V0A2, ATP6V1E1, ATP7A, B3GALT6, B3GAT3, B4GALT7, BGN, CBS, CHST14, COL11A1, COL11A2, COL12A1, COL1A1, COL1A2, COL2A1, COL3A1, COL5A1, COL5A2, COL9A1, COL9A2, COL9A3, DSE, EFEMP2, ELN, FBLN5, FBN1, FBN2, FKBP14, FLNA, LOX, LTBP4, MAT2A, MED12, MFAP5, MYH11, MYLK, NOTCH1, PLOD1, PRDM5, PRKG1, PYCR1, RIN2, SKI, SLC2A10, SLC39A13, SMAD2, SMAD3, SMAD4, TGFB2, TGFB3, TGFBR1, TGFBR2, TNXB, ZNF469
  • Molecular confirmation of a clinical diagnosis in symptomatic individuals
  • Risk assessment of asymptomatic family members of a proband diagnosed with a heritable connective tissue disorder
  • Genetic counseling and recurrence risk determination
  • Deletion/Duplication Analysis
  • Next-Gen Sequencing

Ordering

J555
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81410x1, 81411x1
Yes
Yes
* For price inquiries please email zebras@genedx.com

Forms and Documents

CREATE A CUSTOM PANEL

Test Details

  • Confirmation of clinical diagnosis in symptomatic patients
  • Genetic counseling and risk assessment of asymptomatic family members of a proband with a hereditary cardiovascular condition

Customizable Cardiology Panel

  • Next-Gen Sequencing
  • Deletion/Duplication Analysis

Ordering

J779
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

Varies by gene
No
Yes
* For price inquiries please email zebras@genedx.com

Forms and Documents

CREATE A CUSTOM PANEL

Test Details

  • Molecular confirmation of a clinical diagnosis in symptomatic individuals
  • Risk assessment of asymptomatic family members of a proband diagnosed with a heritable connective tissue disorder
  • Genetic counseling and recurrence risk determination

Customizable Cardiology Panel

  • ExonArray CGH
  • Next-Gen Sequencing

Ordering

J555C
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81410x1, 81411x1
No
Yes
* For price inquiries please email zebras@genedx.com

Forms and Documents

Test Details

ADAMTS2, ALDH18A1, ATP6V0A2, ATP6V1E1, ATP7A, B3GALT6, B3GAT3, B4GALT7, CHST14, COL11A1, COL11A2, COL12A1, COL1A1, COL1A2, COL2A1, COL9A1, COL9A2, COL9A3, DSE, EFEMP2, ELN, FBLN5, FBN1, FKBP14, LTBP4, PLOD1, PRDM5, PYCR1, RIN2, SLC39A13, TNXB, ZNF469
  • Molecular confirmation of a clinical diagnosis in symptomatic individuals
  • Risk assessment of asymptomatic family members of a proband diagnosed with a heritable connective
  • tissue disorder
  • Genetic counseling and recurrence risk determination
  • Next-Gen Sequencing
  • ExonArray CGH

Ordering

883RE
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81408x2; 81479x1
Yes
Yes
* For price inquiries please email zebras@genedx.com