19-47839341-G-C

Variant names:

• chr19-47839341-G-C
• NM_000554.6:c.274G>C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_000554.6(CRX):​c.274G>C​(p.Ala92Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A92T) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CRX NM_000554.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.15

Genes affected

CRX (HGNC:2383): (cone-rod homeobox) The protein encoded by this gene is a photoreceptor-specific transcription factor which plays a role in the differentiation of photoreceptor cells. This homeodomain protein is necessary for the maintenance of normal cone and rod function. Mutations in this gene are associated with photoreceptor degeneration, Leber congenital amaurosis type III and the autosomal dominant cone-rod dystrophy 2. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some variants has not been determined. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a DNA_binding_region Homeobox (size 59) in uniprot entity CRX_HUMAN there are 29 pathogenic changes around while only 2 benign (94%) in NM_000554.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-47839341-G-A is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.927

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRX	NM_000554.6	c.274G>C	p.Ala92Pro	missense_variant	Exon 4 of 4	ENST00000221996.12	NP_000545.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRX	ENST00000221996.12	c.274G>C	p.Ala92Pro	missense_variant	Exon 4 of 4	2	NM_000554.6	ENSP00000221996.5
CRX	ENST00000613299.1	c.122G>C	p.Gly41Ala	missense_variant	Exon 3 of 3	3		ENSP00000478106.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Leber congenital amaurosis 7;C3489532:Cone-rod dystrophy 2 Uncertain:1

Oct 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 92 of the CRX protein (p.Ala92Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CRX-related conditions. ClinVar contains an entry for this variant (Variation ID: 1392198). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt CRX protein function with a positive predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;D
Eigen	Pathogenic	0.77
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	.;D
M_CAP	Pathogenic	0.78	D
MetaRNN	Pathogenic	0.93	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.6	H;H
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-4.6	D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0030	D;D
Polyphen		1.0	D;D
Vest4		0.86
MutPred		0.56		Gain of glycosylation at A92 (P = 0.0019);Gain of glycosylation at A92 (P = 0.0019);
MVP		0.98
MPC		0.81
ClinPred		1.0	D
GERP RS		2.8
Varity_R		0.97
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr19-48342598;