2-208121728-C-T

Variant names:

• chr2-208121728-C-T
• rs121909598
• NM_006891.4:c.470G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_006891.4(CRYGD):​c.470G>A​(p.Trp157*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,728 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CRYGD NM_006891.4 stop_gained
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 2.58
• Publications: 18 publications found

Genes affected

CRYGD (HGNC:2411): (crystallin gamma D) Crystallins are separated into two classes: taxon-specific, or enzyme, and ubiquitous. The latter class constitutes the major proteins of vertebrate eye lens and maintains the transparency and refractive index of the lens. Since lens central fiber cells lose their nuclei during development, these crystallins are made and then retained throughout life, making them extremely stable proteins. Mammalian lens crystallins are divided into alpha, beta, and gamma families; beta and gamma crystallins are also considered as a superfamily. Alpha and beta families are further divided into acidic and basic groups. Seven protein regions exist in crystallins: four homologous motifs, a connecting peptide, and N- and C-terminal extensions. Gamma-crystallins are a homogeneous group of highly symmetrical, monomeric proteins typically lacking connecting peptides and terminal extensions. They are differentially regulated after early development. Four gamma-crystallin genes (gamma-A through gamma-D) and three pseudogenes (gamma-E, gamma-F, gamma-G) are tandemly organized in a genomic segment as a gene cluster. Whether due to aging or mutations in specific genes, gamma-crystallins have been involved in cataract formation. [provided by RefSeq, Jul 2008]

CRYGD Gene-Disease associations (from GenCC):

• cataract 4 multiple types

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• cataract - microcornea syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• cerulean cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• coralliform cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset lamellar cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset nuclear cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• pulverulent cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000295187 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.105 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-208121728-C-T is Pathogenic according to our data. Variant chr2-208121728-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 16941.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRYGD	NM_006891.4	c.470G>A	p.Trp157*	stop_gained	Exon 3 of 3	ENST00000264376.5	NP_008822.2
LOC100507443	NR_038437.1	n.97+2503C>T		intron_variant	Intron 1 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRYGD	ENST00000264376.5	c.470G>A	p.Trp157*	stop_gained	Exon 3 of 3	1	NM_006891.4	ENSP00000264376.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251204 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461728 Hom.: 0 Cov.: 70 AF XY: 0.00 AC XY: 0 AN XY: 727142

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53350

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111934

Other (OTH) AF: 0.00 AC: 0 AN: 60388

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Cataract 4 multiple types Pathogenic:1

Sep 01, 2007

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	37
DANN	Uncertain	0.99
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Uncertain	0.87	D
PhyloP100		2.6
Vest4		0.80
GERP RS		4.3
Mutation Taster		=11/189	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs121909598; hg19: chr2-208986452;