Cone-Rod Dystrophy, Autosomal Recessive

Cone-rod dystrophy (CRD) has an estimated prevalence of 1 in 40,000 individuals. CRD presents first as a macular disease or as a diffuse retinopathy with predominance of the macular involvement. The clinical signs of CRDs reflect the predominant involvement of cones, leading to decreased visual acuity in the first decade of life. However, in some cases, diffuse retinopathy affects simultaneously cones and rods, resulting in both night blindness and loss of visual acuity. The visual field testing shows central scotomas, while the periphery is spared. Fundus examination shows pigment deposits and retinal atrophy in the macular region. At a later stage, patients are legally blind, even though large parts of the peripheral visual field remain preserved. The electroretinogram (ERG), is distinguished by a more distinctive reduction of the photopic cone b-wave amplitude than the scotopic rod b-wave amplitude, compared to rod degeneration.

Tests Available

Forms and Documents

Test Details

CERKL
  • Confirmation of a clinical diagnosis
  • Determine if a sporadic case is recessive or dominant (de novo)
  • Carrier testing for family members of an affected individual with known mutation(s)
  • Prenatal diagnosis in at-risk pregnancies
  • Presymptomatic testing
  • Genetic counseling
  • Capillary Sequencing

Ordering

506
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81479x1
No
Yes
  • 743.53 Chorioretinal degeneration, congenital
  • 743.55 Congenital macular changes
  • 362.76 Dystrophies primarily involving the retinal pigment epithelium, Fundus flavimaculatus, Vitelliform dystrophy
  • 362.75 Other dystrophies
  • 743.56 Other retinal changes, congenital
  • 362.74 Pigmentary retinal dystrophy, Retinal dystrophy, albipunctate, Retinitis pigmentosa
* For price inquiries please email zebras@genedx.com

References

  1. Thiadens et al., (2010) Ophthalmology 117(4):825- 30
  2. Kitiratschky et al., (2008) Invest Ophthalmol Vis Sci 49:5015
  3. Hamel CP et al., (2007) Orphanet J Rare Dis (1)2:7
  4. Rivolta C et al., (2001) Hum Mutat 18: 488-498
  5. Freund CL et al., (1997) Cell. 91(4):543- 553
  6. Lotery AJ (2000) Arch Ophthalmol]. 118(4):538-43
  7. Sohocki et al., (2000) Mol Genet Metab 70:142–150
  8. Boon CJ et al., (2008) Prog Retin Eye Res 27:213-35
  9. Allikmets, et al (1998) Gene 215: 111-122
  10. Cremers F P M et al., (1998) Hum Molec Genet 7: 355-362
  11. Wissinger et al., (2001) Am J Hum Genet 69:722-737
  12. Klevering B J et al., (2004) Eur J Hum Genet.12(12):1024-32
  13. Downes et al., (2001) Arch Ophthalmol 119:96-105
  14. Michaelides et al., (2005) Ophthalmology 112:1442-1447
  15. Kitiratschy et al., (2009) Human Mutation 30:E782-E796
  16. Littink et al., (2010) Invest Ophthalmol Vis Sci 51(11):5943-5951
  17. Wissinger et al., (2001) Am J Hum Genet 69:722-737

Forms and Documents

Test Details

CNGA3
  • Confirmation of a clinical diagnosis
  • Development of an appropriate management plan
  • Prenatal diagnosis in families with a defined mutation
  • Capillary Sequencing

Ordering

514
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Dried Blood Spots|Buccal Swabs

Billing

81479x1
No
Yes
  • 368.54 Achromatopsia Monochromatism (cone) (rod)
* For price inquiries please email zebras@genedx.com

References

  1. Kolh et al., (2000) Hum Mol Genet 9:2107-2116
  2. Kohl et al., (2005) Eur J Him Genet 13:302-308
  3. Thiadens et al., (2010) Ophthalmology 117:825-830
  4. Wiszniewski et al., (2007) Hum Genet 121:433-439
  5. Sundin et al., (2000) Nat Genet 25:289-293

Forms and Documents

Test Details

CNGB3
  • Confirmation of a clinical diagnosis
  • Development of an appropriate management plan
  • Prenatal diagnosis in families with a defined mutation
  • Capillary Sequencing

Ordering

513
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81479x1
No
Yes
  • 368.54 Achromatopsia Monochromatism (cone) (rod)
* For price inquiries please email zebras@genedx.com

References

  1. Thiadens et al., (2010) Ophthalmology 117:825-830
  2. Kohl et al., (2005) Eur J Him Genet 13:302-308
  3. Kolh et al., (2000) Hum Mol Genet 9:2107-2116
  4. Sundin et al., (2000) Nat Genet 25:289-293
  5. Wiszniewski et al., (2007) Hum Genet 121:433-439

Forms and Documents

Test Details

ABCA4, RDS (PRPH2)
  • Confirmation of a clinical diagnosis
  • Determine if a sporadic case is recessive or dominant (de novo)
  • Carrier testing for family members of an affected individual with known mutation(s)
  • Prenatal diagnosis in at-risk pregnancies
  • Presymptomatic testing
  • Next-Gen Sequencing

Ordering

468
3 weeks
2-5 mL Blood - Lavender Top Tube

Billing

81408x1, 81404x1
No
Yes
  • 743.53 Chorioretinal degeneration, congenital
  • 743.54 Congenital folds and cysts of posterior segment
  • 743.55 Congenital macular changes
  • 362.76 Dystrophies primarily involving the retinal pigment epithelium, Fundus flavimaculatus, Vitelliform dystrophy
  • 362.75 Other dystrophies
  • 743.56 Other retinal changes, congenital
  • 362.74 Pigmentary retinal dystrophy, Retinal dystrophy, albipunctate, Retinitis pigmentosa
* For price inquiries please email zebras@genedx.com

References

  1. Michaelides et al., (2005) Ophthalmology 112:1442-1447
  2. Kitiratschy et al., (2009) Human Mutation 30:E782-E796
  3. Downes et al., (2001) Arch Ophthalmol 119:96-105
  4. Klevering B J et al., (2004) Eur J Hum Genet.12(12):1024-32
  5. Sohocki et al., (2000) Mol Genet Metab 70:142–150
  6. Boon CJ et al., (2008) Prog Retin Eye Res 27:213-35
  7. Cremers F P M et al., (1998) Hum Molec Genet 7: 355-362
  8. Allikmets, et al (1998) Gene 215: 111-122
  9. Freund CL et al., (1997) Cell. 91(4):543- 553
  10. Lotery AJ (2000) Arch Ophthalmol]. 118(4):538-43
  11. Hamel CP et al., (2007) Orphanet J Rare Dis (1)2:7
  12. Rivolta C et al., (2001) Hum Mutat 18: 488-498
  13. Kitiratschky et al., (2008) Invest Ophthalmol Vis Sci 49:5015

Forms and Documents

Test Details

  • Molecular confirmation of a clinical diagnosis
  • To assist with decisions about treatment and management of individuals with retinal dystrophies
  • Testing of at-risk relatives for specific known variant(s) previously identified in an affected family member
  • Prenatal diagnosis for known familial pathogenic variant(s) in at-risk pregnancies
  • Next-Gen Sequencing

Ordering

J905
6 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81434x1
Yes
Yes
* For price inquiries please email zebras@genedx.com

References

  1. Sahel et al. (2014) Cold Spring Harb Perspect Med 5 (2):a017111 (PMID: 25324231)
  2. Kocur et al. (2002) Br J Ophthalmol 86 (7):716-22 (PMID: 12084735);
  3. Ayuso et al. (2010) Genome Med 2 (5):34 (PMID: 20519033)
  4. Finger et al. (2011) Invest. Ophthalmol. Vis. Sci. 52 (7):4381-9 (PMID: 21447690)
  5. den Hollander et al. (2006) American Journal Of Human Genetics 79 (3):556-61 (PMID: 16909394)
  6. Braun et al. (2013) Human Molecular Genetics 22 (25):5136-45 (PMID: 23918662)
  7. Zernant et al. (2014) Hum. Mol. Genet. 23 (25):6797-806 (PMID: 25082829)
  8. Bauwens et al. (2015) Hum. Mutat. 36 (1):39-42 (PMID: 25346251)
  9. Schulz et al. (2017) Invest. Ophthalmol. Vis. Sci. 58 (1):394-403 (PMID: 28118664)
  10. Beryozkin et al. (2015) Sci Rep 5 :13187 (PMID: 26306921)
  11. Lee et al. (2015) Am. J. Ophthalmol. 160 (2):354-363.e9 (PMID: 25910913)
  12. de Castro-Miro et al. (2016) PLoS ONE 11 (12):e0168966 (PMID: 28005958)
  13. Haer-Wigman et al. (2017) Eur. J. Hum. Genet. 25 (5):591-599 (PMID: 28224992)
  14. Riera et al. (2017) Sci Rep 7 :42078 (PMID: 28181551)
  15. Carss et al. (2017) Am. J. Hum. Genet. 100 (1):75-90 (PMID: 28041643)
  16. Retterer et al. (2015) Genet. Med.: (PMID: 26633542)