11-67417568-G-C

Position:

• chr11-67417568-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001166222.2(CARNS1):​c.165G>C​(p.Glu55Asp) 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 benign outcome for this variant. 12/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: CARNS1 NM_001166222.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.359

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1482977).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CARNS1	NM_001166222.2	c.165G>C	p.Glu55Asp	missense_variant	3/10	ENST00000687366.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CARNS1	ENST00000687366.1	c.165G>C	p.Glu55Asp	missense_variant	3/10		NM_001166222.2	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 23, 2023

The c.165G>C (p.E55D) alteration is located in exon 3 (coding exon 2) of the CARNS1 gene. This alteration results from a G to C substitution at nucleotide position 165, causing the glutamic acid (E) at amino acid position 55 to be replaced by an aspartic acid (D). 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
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.40
CADD	Benign	18
DANN	Uncertain	1.0
Eigen	Benign	-0.35
Eigen_PC	Benign	-0.50
FATHMM_MKL	Benign	0.63	D
LIST_S2	Benign	0.74	T;T
M_CAP	Benign	0.059	D
MetaRNN	Benign	0.15	T;T
MetaSVM	Benign	-0.72	T
MutationTaster	Benign	1.0	N;N;N;N
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-0.97	N;N
REVEL	Benign	0.14
Sift	Pathogenic	0.0	D;D
Sift4G	Benign	0.24	T;T
Vest4		0.15
MVP		0.48
MPC		0.47
ClinPred		0.53	D
GERP RS		-1.3
gMVP		0.17

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs1401231306; hg19: chr11-67185039;