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Undetectable light-adapted electroretinogram

MedGen UID:
893040
Concept ID:
C4072955
Finding
Synonyms: Absent photopic (cone) responses on ERG; non-detectable photopic ERG
 
HPO: HP:0030465

Definition

No detectable response to the light-adapted 3.0 ERG (single-flash cone response). This type of ERG measures responses of the cone system; a-waves arise from cone photoreceptors and cone off-bipolar cells; the b-wave comes from On- and Off-cone bipolar cells. [from HPO]

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVUndetectable light-adapted electroretinogram

Conditions with this feature

Achromatopsia 2
MedGen UID:
387867
Concept ID:
C1857618
Disease or Syndrome
Achromatopsia is characterized by reduced visual acuity, pendular nystagmus, increased sensitivity to light (photophobia), a small central scotoma, eccentric fixation, and reduced or complete loss of color discrimination. All individuals with achromatopsia (achromats) have impaired color discrimination along all three axes of color vision corresponding to the three cone classes: the protan or long-wavelength-sensitive cone axis (red), the deutan or middle-wavelength-sensitive cone axis (green), and the tritan or short-wavelength-sensitive cone axis (blue). Most individuals have complete achromatopsia, with total lack of function of all three types of cones. Rarely, individuals have incomplete achromatopsia, in which one or more cone types may be partially functioning. The manifestations are similar to those of individuals with complete achromatopsia, but generally less severe. Hyperopia is common in achromatopsia. Nystagmus develops during the first few weeks after birth followed by increased sensitivity to bright light. Best visual acuity varies with severity of the disease; it is 20/200 or less in complete achromatopsia and may be as high as 20/80 in incomplete achromatopsia. Visual acuity is usually stable over time; both nystagmus and sensitivity to bright light may improve slightly. Although the fundus is usually normal, macular changes (which may show early signs of progression) and vessel narrowing may be present in some affected individuals. Defects in the macula are visible on optical coherence tomography.
Cone dystrophy 4
MedGen UID:
416518
Concept ID:
C2751308
Disease or Syndrome
Achromatopsia is characterized by reduced visual acuity, pendular nystagmus, increased sensitivity to light (photophobia), a small central scotoma, eccentric fixation, and reduced or complete loss of color discrimination. All individuals with achromatopsia (achromats) have impaired color discrimination along all three axes of color vision corresponding to the three cone classes: the protan or long-wavelength-sensitive cone axis (red), the deutan or middle-wavelength-sensitive cone axis (green), and the tritan or short-wavelength-sensitive cone axis (blue). Most individuals have complete achromatopsia, with total lack of function of all three types of cones. Rarely, individuals have incomplete achromatopsia, in which one or more cone types may be partially functioning. The manifestations are similar to those of individuals with complete achromatopsia, but generally less severe. Hyperopia is common in achromatopsia. Nystagmus develops during the first few weeks after birth followed by increased sensitivity to bright light. Best visual acuity varies with severity of the disease; it is 20/200 or less in complete achromatopsia and may be as high as 20/80 in incomplete achromatopsia. Visual acuity is usually stable over time; both nystagmus and sensitivity to bright light may improve slightly. Although the fundus is usually normal, macular changes (which may show early signs of progression) and vessel narrowing may be present in some affected individuals. Defects in the macula are visible on optical coherence tomography.

Recent clinical studies

Etiology

Alzahem TA, AlTheeb A, Ba-Abbad R
Ophthalmic Genet 2024 Feb;45(1):72-77. Epub 2023 May 29 doi: 10.1080/13816810.2023.2204361. PMID: 37246743
Brunetti-Pierri R, Karali M, Melillo P, Di Iorio V, De Benedictis A, Iaccarino G, Testa F, Banfi S, Simonelli F
Int J Mol Sci 2021 Feb 7;22(4) doi: 10.3390/ijms22041681. PMID: 33562422Free PMC Article
Lie H, Wang G, Liu X, Meng X, Long Y, Ren J, Yang L, Fujinami-Yokokawa Y, Kurihara T, Tsubota K, Fujinami K, Li S
Ophthalmic Genet 2021 Apr;42(2):144-149. Epub 2020 Dec 29 doi: 10.1080/13816810.2020.1861307. PMID: 33372566

Diagnosis

Alzahem TA, AlTheeb A, Ba-Abbad R
Ophthalmic Genet 2024 Feb;45(1):72-77. Epub 2023 May 29 doi: 10.1080/13816810.2023.2204361. PMID: 37246743
Brunetti-Pierri R, Karali M, Melillo P, Di Iorio V, De Benedictis A, Iaccarino G, Testa F, Banfi S, Simonelli F
Int J Mol Sci 2021 Feb 7;22(4) doi: 10.3390/ijms22041681. PMID: 33562422Free PMC Article
Racine J, Golden R
Doc Ophthalmol 2021 Aug;143(1):75-83. Epub 2021 Feb 6 doi: 10.1007/s10633-021-09820-4. PMID: 33548032
Lie H, Wang G, Liu X, Meng X, Long Y, Ren J, Yang L, Fujinami-Yokokawa Y, Kurihara T, Tsubota K, Fujinami K, Li S
Ophthalmic Genet 2021 Apr;42(2):144-149. Epub 2020 Dec 29 doi: 10.1080/13816810.2020.1861307. PMID: 33372566

Prognosis

Brunetti-Pierri R, Karali M, Melillo P, Di Iorio V, De Benedictis A, Iaccarino G, Testa F, Banfi S, Simonelli F
Int J Mol Sci 2021 Feb 7;22(4) doi: 10.3390/ijms22041681. PMID: 33562422Free PMC Article
Lie H, Wang G, Liu X, Meng X, Long Y, Ren J, Yang L, Fujinami-Yokokawa Y, Kurihara T, Tsubota K, Fujinami K, Li S
Ophthalmic Genet 2021 Apr;42(2):144-149. Epub 2020 Dec 29 doi: 10.1080/13816810.2020.1861307. PMID: 33372566

Clinical prediction guides

Brunetti-Pierri R, Karali M, Melillo P, Di Iorio V, De Benedictis A, Iaccarino G, Testa F, Banfi S, Simonelli F
Int J Mol Sci 2021 Feb 7;22(4) doi: 10.3390/ijms22041681. PMID: 33562422Free PMC Article

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