11-67418848-G-T

Variant names:

• chr11-67418848-G-T
• rs1863613252
• NM_001166222.2:c.457G>T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001166222.2(CARNS1):​c.457G>T​(p.Val153Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000069 in 1,448,582 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CARNS1 NM_001166222.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.13

Genes affected

CARNS1 (HGNC:29268): (carnosine synthase 1) CARNS1 (EC 6.3.2.11), a member of the ATP-grasp family of ATPases, catalyzes the formation of carnosine (beta-alanyl-L-histidine) and homocarnosine (gamma-aminobutyryl-L-histidine), which are found mainly in skeletal muscle and the central nervous system, respectively (Drozak et al., 2010 [PubMed 20097752]).[supplied by OMIM, Apr 2010]

PPP1CA (HGNC:9281): (protein phosphatase 1 catalytic subunit alpha) The protein encoded by this gene is one of the three catalytic subunits of protein phosphatase 1 (PP1). This broadly expressed gene encodes the alpha subunit of the PP1 complex that associates with over 200 regulatory proteins to form holoenzymes which dephosphorylate their biological targets with high specificity. PP1 is a serine/threonine specific protein phosphatase known to be involved in the regulation of a variety of cellular processes, such as cell division, glycogen metabolism, muscle contractility, protein synthesis, and HIV-1 viral transcription. Increased PP1 activity has been observed in the end stage of heart failure. Studies suggest that PP1 is an important regulator of cardiac function and that PP1 deregulation is implicated in diabetes and multiple types of cancer. Three alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2020]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CARNS1	NM_001166222.2	c.457G>T	p.Val153Leu	missense_variant	Exon 5 of 10	ENST00000687366.1	NP_001159694.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CARNS1	ENST00000687366.1	c.457G>T	p.Val153Leu	missense_variant	Exon 5 of 10		NM_001166222.2	ENSP00000510668.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.90e-7 AC: 1 AN: 1448582 Hom.: 0 Cov.: 32 AF XY: 0.00000139 AC XY: 1 AN XY: 719552

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: 9.04e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000370 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Jan 24, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.457G>T (p.V153L) alteration is located in exon 5 (coding exon 4) of the CARNS1 gene. This alteration results from a G to T substitution at nucleotide position 457, causing the valine (V) at amino acid position 153 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.37
BayesDel_addAF	Benign	-0.047	T
BayesDel_noAF	Benign	-0.31
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.0088	.;T;.
Eigen	Uncertain	0.30
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.82	T;T;T
M_CAP	Benign	0.021	T
MetaRNN	Uncertain	0.54	D;D;D
MetaSVM	Benign	-0.76	T
MutationAssessor	Benign	0.81	.;L;.
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-1.1	N;N;N
REVEL	Benign	0.11
Sift	Uncertain	0.0030	D;D;D
Sift4G	Uncertain	0.028	D;D;D
Polyphen		0.90	.;P;.
Vest4		0.69
MutPred		0.45		.;Loss of sheet (P = 0.0084);.;
MVP		0.60
MPC		0.42
ClinPred		0.68	D
GERP RS		4.0
Varity_R		0.20
gMVP		0.38

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs1863613252; hg19: chr11-67186319;