NM_000283.4:c.754G>T

Variant names:

• chr4-653894-G-T
• rs1210313417
• NM_000283.4:c.754G>T

Variant summary

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

The NM_000283.4(PDE6B):​c.754G>T​(p.Asp252Tyr) 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. 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. D252N) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: PDE6B NM_000283.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.57

Genes affected

PDE6B (HGNC:8786): (phosphodiesterase 6B) Photon absorption triggers a signaling cascade in rod photoreceptors that activates cGMP phosphodiesterase (PDE), resulting in the rapid hydrolysis of cGMP, closure of cGMP-gated cation channels, and hyperpolarization of the cell. PDE is a peripheral membrane heterotrimeric enzyme made up of alpha, beta, and gamma subunits. This gene encodes the beta subunit. Mutations in this gene result in retinitis pigmentosa and autosomal dominant congenital stationary night blindness. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2009]

PDE6B-AS1 (HGNC:40438): (PDE6B antisense RNA 1)

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a domain GAF 2 (size 177) in uniprot entity PDE6B_HUMAN there are 19 pathogenic changes around while only 1 benign (95%) in NM_000283.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr4-653894-G-A is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.9

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PDE6B	NM_000283.4	c.754G>T	p.Asp252Tyr	missense_variant	Exon 4 of 22	ENST00000496514.6	NP_000274.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PDE6B	ENST00000496514.6	c.754G>T	p.Asp252Tyr	missense_variant	Exon 4 of 22	1	NM_000283.4	ENSP00000420295.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Mar 27, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid with tyrosine at codon 252 of the PDE6B protein (p.Asp252Tyr). The aspartic acid residue is highly conserved and there is a large physicochemical difference between aspartic acid and tyrosine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has been observed in individual(s) with clinical features of retinitis pigmentosa (Invitae). This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.81	.;D
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Benign	0.081	D
MetaRNN	Pathogenic	0.90	D;D
MetaSVM	Uncertain	0.39	D
MutationAssessor	Pathogenic	3.2	M;M
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-6.4	D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	D;D
Vest4		0.97
MutPred		0.65		Loss of disorder (P = 0.1236);Loss of disorder (P = 0.1236);
MVP		0.95
MPC		0.66
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.85
gMVP		0.75

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

LitVar

Other links and lift over

dbSNP: rs1210313417; hg19: chr4-647683;