Congenital Stationary Night Blindness, Autosomal Dominant

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

GNAT1
  • Confirmation of a clinical diagnosis.
  • Development of an appropriate management plan.
  • Prenatal diagnosis in families with a defined mutation.
  • Capillary Sequencing

Ordering

589
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. Nakamura et al., (2000) Invest Ophthalmol Vis Sci 41(12):3925-32
  2. Nakamura et al. (2003) Doc Ophthalmol 107(1):3-11
  3. Yamamoto H et al., (1999) Nat Genet 22:188-91
  4. Zeitz C (2005) Invest Ophthalmol Vis Sci 46(11):4328-35
  5. Zeitz C (2006) Am J Hum Genet 79(4):657-67
  6. Dryja et al., (1996) Nat Genet 13(3):358-60
  7. Naeem MA et al., (2012) Invest Ophthalmol Vis Sci 53(3):1353-61
  8. Szabo V et al., (2007) Hum Mutat 28(7):741-2
  9. Dryja et al., (1993) Nat Genet 4:280-283
  10. al-Jandal et al., (1999) Human Mutation 13:75-81
  11. Yamamoto et al., (1997) Nat Genet 15(2):175-178
  12. Nakamura et al., (2004) American Academy of Ophthalmology 111(7):1410-1414
  13. Nakazawa et al., (1998) Arch Ophthalmol 116:498-501
  14. Fuchs et al., (1995) Nat Genet 10:360-362
  15. van Genderen et al., (2009) Am J Hum Genet 85: 730-736
  16. Audo et al., (2009) Am J Hum Genet 85: 720-729
  17. Li et al., (2009) Am J Hum Genet 85:711-719
  18. Bech-Hansen et al., (2000) Nat Genet 26: 319- 323
  19. Xiao et al., (2006) J Hum Genet 51:634-640
  20. Pusch et al., (2000) Nat Genet 26:324-327

Forms and Documents

Test Details

RHO
  • Confirmation of a clinical diagnosis
  • To differentiate from other forms of retinal dystrophy
  • Recurrence risk assessment
  • Prenatal diagnosis
  • Capillary Sequencing

Ordering

298
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81404x1
No
Yes
  • 362.74 Pigmentary retinal dystrophy, Retinal dystrophy, albipunctate, Retinitis pigmentosa
* For price inquiries please email zebras@genedx.com

References

  1. Naushin W(2007) Invest Ophthalmol Vis Sci, Mar;48(3):1330-4
  2. Dryja TP (1991) Proc. Natl. Acad. Sci. USA Vol. 88, pp. 9370-9374
  3. Riazuddin SA (2005) Invest Ophthalmol Vis Sci. Jul;46(7):2264-70
  4. Davidson et al., (2009) Am J Hum Genet 85:581-592
  5. Sullivan LS (2006) Invest Ophthalmol Vis Sci. Oct;47(10):4579-88
  6. Browne SJ (2006) Invest Ophthalmol Vis Sci. Jan;47(1):34-42
  7. Kajiwara K (1993) Nat Genet.Mar;3(3):208-12
  8. Kennan A (2005) Trends Genet Feb;21(2):103-10
  9. Sullivan LS (2006) Invest Ophthalmol Vis Sci. Jul;47(7):3052-64
  10. Gamundi MJ (2007). Mol Vis. Jun 28;13:1031-7
  11. Retnet http://www.sph.uth. tmc.edu/RetNet/
  12. Ziviello C (2005). J Med Genet. Jul;42(7):e47
  13. Bunker CH (1984) Am J Ophthalmol; 97: 357–6522
  14. Haim M (2002) Acta Ophthalmol Scand Suppl 80:1-34