Congenital Stationary Night Blindness, X-Linked

Congenital stationary night blindness (CSNB) is a group of congenital retinal dystrophies currently associated with two X-linked genes (NYX, CACNA1F), six autosomal recessive genes (CABP4, GRK1, GRM6, RDH5, SAG, TRPM1), and three autosomal dominant genes (GNAT1, PDE6B, RHO). CSNB can be subcategorized into two subgroups, “complete” or “incomplete,” defined by the presence or the absence of residual rod function measured by dark adaptometry or electroretinogram (ERG). The NYX and the TRPM1 gene mutations are mainly responsible for the complete form of CSNB. Patients with complete X-linked CSNB usually have high myopia with a tigroid-appearing fundus. Some patients have mild nystagmus. All patients with stationary night blindness have an abnormal dark-adaptation curve and an abnormal ERG. The ERG demonstrates a severely reduced or absent dark-adapted rod-mediated b-wave response (Pusch et al., 2000 and Bech-Hansen et al., 2000). In particular, this analysis will produce a subnormal ratio of b-wave to a-wave amplitude when using a white flash in the dark (Pusch et al., 2000 and Bech-Hansen et al., 2000). Reduced oscillatory potentials and cone ERGs that are normal to mildly abnormal are also typical findings (Pusch et al., 2000 and Bech- Hansen et al., 2000). CSNB, Leber congenital amaurosis (LCA), and complete achromatopsia are three types of congenital retinal dystrophies that overlap clinically, as all patients present in early childhood with visual impairment and nystagmus.

Tests Available

Forms and Documents

Test Details

CACNA1F
  • Confirmation of a clinical diagnosis.
  • Development of an appropriate management plan.
  • Prenatal diagnosis in families with a defined mutation.
  • Capillary Sequencing

Ordering

587
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81479x1
No
Yes
  • 368.61 Congenital night blindness, Hereditary night blindness, Oguchi's disease
* For price inquiries please email zebras@genedx.com

References

  1. Xiao et al., (2006) J Hum Genet 51:634-640
  2. Bech-Hansen et al., (2000) Nat Genet 26: 319- 323
  3. Pusch et al., (2000) Nat Genet 26:324-327
  4. Li et al., (2009) Am J Hum Genet 85:711-719
  5. Audo et al., (2009) Am J Hum Genet 85: 720-729
  6. van Genderen et al., (2009) Am J Hum Genet 85: 730-736
  7. Fuchs et al., (1995) Nat Genet 10:360-362
  8. Nakazawa et al., (1998) Arch Ophthalmol 116:498-501
  9. Nakamura et al., (2004) American Academy of Ophthalmology 111(7):1410-1414
  10. Yamamoto et al., (1997) Nat Genet 15(2):175-178
  11. Nakamura et al., (2000) Invest Ophthalmol Vis Sci 41(12):3925-32
  12. Nakamura et al. (2003) Doc Ophthalmol 107(1):3-11
  13. Yamamoto H et al., (1999) Nat Genet 22:188-91
  14. al-Jandal et al., (1999) Human Mutation 13:75-81
  15. Dryja et al., (1993) Nat Genet 4:280-283
  16. Szabo V et al., (2007) Hum Mutat 28(7):741-2
  17. Naeem MA et al., (2012) Invest Ophthalmol Vis Sci 53(3):1353-61
  18. Dryja et al., (1996) Nat Genet 13(3):358-60
  19. Zeitz C (2006) Am J Hum Genet 79(4):657-67
  20. Zeitz C (2005) Invest Ophthalmol Vis Sci 46(11):4328-35

Forms and Documents

Test Details

NYX
  • Confirmation of a clinical diagnosis.
  • Development of an appropriate management plan.
  • Prenatal diagnosis in families with a defined mutation
  • Capillary Sequencing

Ordering

431
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Dried Blood Spots | Buccal Swabs

Billing

81479x1
No
Yes
  • 368.63 Abnormal dark adaptation curve, Abnormal threshold of cones or rods, Delayed adaptation of cones or rods
  • 368.61 Congenital night blindness, Hereditary night blindness, Oguchi's disease
* For price inquiries please email zebras@genedx.com

References

  1. van Genderen et al., (2009) Am J Hum Genet 85: 730-736
  2. Audo et al., (2009) Am J Hum Genet 85: 720- 729
  3. Li et al., (2009) Am J Hum Genet 85:711-719
  4. Xiao et al., (2006) J Hum Genet 51:634-640
  5. Pusch et al., (2000) Nat Genet 26:324-327
  6. Bech-Hansen et al., (2000) Nat Genet 26: 319-323

Forms and Documents

Test Details

CABP4, CACNA1F, CHM, GNAT1, GRM6, NYX, PDE6B, RDH5, RHO, RPE65, SAG, TRPM1
  • Nonprogressive difficulty seeing in low light, existing from birth
  • Reduced visual acuity, myopia, and occasionally nystagmus and strabismus
  • Asymptomatic mothers with affected sons (X-linked inheritance)
  • Exon Array Dx
  • Next-Gen Sequencing

Ordering

J959
4 weeks
2-5 mL Blood - Lavender Top Tube
Buccal Swab

Billing

81404x1; 81479x1
No
Yes
* For price inquiries please email zebras@genedx.com

References

  1. Xiao et al., (2006) J Hum Genet 51:634-640
  2. Bech-Hansen et al., (2000) Nat Genet 26: 319- 323
  3. Pusch et al., (2000) Nat Genet 26:324-327
  4. Li et al., (2009) Am J Hum Genet 85:711-719
  5. Audo et al., (2009) Am J Hum Genet 85: 720-729
  6. van Genderen et al., (2009) Am J Hum Genet 85: 730-736
  7. Fuchs et al., (1995) Nat Genet 10:360-362
  8. Nakazawa et al., (1998) Arch Ophthalmol 116:498-501
  9. Nakamura et al., (2004) American Academy of Ophthalmology 111(7):1410-1414
  10. Jalkanen et al., (2007) Invest Opthalmol Vis Sci 48:2498-502 (PMID: 17525176)
  11. Nakamura et al., (2000) Invest Ophthalmol Vis Sci 41(12):3925-32
  12. Nakamura et al., (2003) Doc Ophthalmol 107(1):3-11
  13. Wutz et al., (2002) Eur J Hum Genet 10:449-56 (PMID: 12111638)
  14. al-Jandal et al., (1999) Human Mutation 13:75-81
  15. Dryja et al., (1993) Nat Genet 4:280-283
  16. Szabo et al., (2007) Hum Mutat 28(7):741-2
  17. Naeem et al., (2012) Invest Ophthalmol Vis Sci 53(3):1353-61
  18. Zeitz C (2006) Am J Hum Genet 79(4):657-67
  19. Zeitz C (2005) Invest Ophthalmol Vis Sci 46(11):4328-35
  20. Manes et al., (2014) PLoS 9(4):e95768
  21. Gopalakrishna et al. (2017) Cell. Signal. 37 :74-80
  22. Vincent et al., (2016) Am J Hum Gen 98(5):1011-1019
  23. Peachey et al., (2012) Am J Hum Gen 90(2):331-
  24. Audo et al., (2012) Am J Hum Gen 90(2):321-30
  25. Zeitz et al (2013) Am J Hum Gen 92:67-75
  26. Riazuddin et at., (2010) Am J Hum Gen 87(4): 523-31
  27. Neuille et al., (2016) Clin Genet 89: 690-699
  28. Esposito et al. (2011) Human Mutation 32 (12):1460-9
  29. Morimura et al. (1998) Proc. Natl. Acad. Sci. U.S.A. 95 (6):3088-93
  30. den Hollander et al. (2008) Prog Retin Eye Res 27 (4):391-419
  31. Dryja et al., (2005) Proc Natl Acad Sci U.S.A. 102:4884-9
  32. Zeitz et al. (2015) Prog Retin Eye Res 45 :58-110 (PMID: 25307992)