12-69586340-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_006431.3(CCT2):c.74G>C(p.Arg25Pro) 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. R25H) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CCT2 NM_006431.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.88

Genes affected

CCT2 (HGNC:1615): (chaperonin containing TCP1 subunit 2) The protein encoded by this gene is a molecular chaperone that is a member of the chaperonin containing TCP1 complex (CCT), also known as the TCP1 ring complex (TRiC). This complex consists of two identical stacked rings, each containing eight different proteins. Unfolded polypeptides enter the central cavity of the complex and are folded in an ATP-dependent manner. The complex folds various proteins, including actin and tubulin. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.874

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CCT2	NM_006431.3	c.74G>C	p.Arg25Pro	missense_variant	2/16	ENST00000299300.11
CCT2	NM_001198842.2	c.-68G>C		5_prime_UTR_variant	2/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CCT2	ENST00000299300.11	c.74G>C	p.Arg25Pro	missense_variant	2/16	1	NM_006431.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 08, 2022

This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 25 of the CCT2 protein (p.Arg25Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CCT2-related conditions. 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"). 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	0.99
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
Cadd	Pathogenic	31
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.73	D;T
Eigen	Uncertain	0.51
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Benign	0.068	D
MetaRNN	Pathogenic	0.87	D;D
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.9	M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-6.2	D;D
REVEL	Uncertain	0.48
Sift	Uncertain	0.0080	D;D
Sift4G	Uncertain	0.0090	D;D
Polyphen		1.0	D;D
Vest4		0.94
MutPred		0.59		Gain of glycosylation at R25 (P = 0.0407);Gain of glycosylation at R25 (P = 0.0407);
MVP		0.63
MPC		1.2
ClinPred		1.0	D
GERP RS		3.6
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.0
Varity_R		0.96
gMVP		0.98

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: chr12-69980120;