NM_006891.4:c.109C>T

Variant names:

• chr2-208124255-G-A
• rs121909597
• NM_006891.4:c.109C>T

Variant summary

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

The NM_006891.4(CRYGD):​c.109C>T​(p.Arg37Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R37P) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CRYGD NM_006891.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.69

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]

LOC100507443 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a domain Beta/gamma crystallin 'Greek key' 1 (size 38) in uniprot entity CRGD_HUMAN there are 13 pathogenic changes around while only 0 benign (100%) in NM_006891.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-208124254-C-G is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.937

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRYGD	NM_006891.4	c.109C>T	p.Arg37Cys	missense_variant	Exon 2 of 3	ENST00000264376.5	NP_008822.2
LOC100507443	NR_038437.1	n.97+5030G>A		intron_variant	Intron 1 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRYGD	ENST00000264376.5	c.109C>T	p.Arg37Cys	missense_variant	Exon 2 of 3	1	NM_006891.4	ENSP00000264376.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000205 AC: 3 AN: 1459922 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 726238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.24
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.26
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.80	D
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.28
FATHMM_MKL	Benign	0.62	D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Uncertain	0.55	D
MutationAssessor	Pathogenic	3.8	H
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-7.4	D
REVEL	Pathogenic	0.69
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.83
MutPred		0.74		Loss of sheet (P = 0.1158);
MVP		0.89
MPC		1.0
ClinPred		1.0	D
GERP RS		3.4
Varity_R		0.96
gMVP		0.80

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: rs121909597; hg19: chr2-208988979; COSMIC: COSV52205459; COSMIC: COSV52205459;