2-28752144-A-C

Position:

• chr2-28752144-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_002709.3(PPP1CB):​c.20A>C​(p.Asn7Thr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign 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. N7K) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 30)
• Consequence: PPP1CB NM_002709.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.92

Genes affected

PPP1CB (HGNC:9282): (protein phosphatase 1 catalytic subunit beta) The protein encoded by this gene is one of the three catalytic subunits of protein phosphatase 1 (PP1). 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. Mouse studies suggest that PP1 functions as a suppressor of learning and memory. Two alternatively spliced transcript variants encoding distinct isoforms have been observed. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), PPP1CB. . Gene score misZ 4.3319 (greater than the threshold 3.09). Trascript score misZ 4.7349 (greater than threshold 3.09). GenCC has associacion of gene with Noonan syndrome-like disorder with loose anagen hair 2, Noonan syndrome-like disorder with loose anagen hair.
• BP4: Computational evidence support a benign effect (MetaRNN=0.327653).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PPP1CB	NM_002709.3	c.20A>C	p.Asn7Thr	missense_variant	1/8	ENST00000395366.3
PPP1CB	NM_206876.2	c.20A>C	p.Asn7Thr	missense_variant	2/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PPP1CB	ENST00000395366.3	c.20A>C	p.Asn7Thr	missense_variant	1/8	1	NM_002709.3	P1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 30

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

Labcorp Genetics (formerly Invitae), Labcorp

Jan 20, 2024

This sequence change replaces asparagine, which is neutral and polar, with threonine, which is neutral and polar, at codon 7 of the PPP1CB protein (p.Asn7Thr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PPP1CB-related conditions. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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	Benign	0.25
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.39
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Benign	0.023	.;T;T;T;T
Eigen	Benign	0.077
Eigen_PC	Benign	0.19
FATHMM_MKL	Benign	0.51	D
LIST_S2	Pathogenic	0.98	D;D;D;.;.
M_CAP	Uncertain	0.12	D
MetaRNN	Benign	0.33	T;T;T;T;T
MetaSVM	Benign	-0.90	T
MutationAssessor	Uncertain	2.6	.;.;M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.94	D
PROVEAN	Benign	-2.0	N;N;N;N;N
REVEL	Benign	0.16
Sift	Benign	0.042	D;D;D;D;D
Sift4G	Uncertain	0.060	T;T;T;T;T
Polyphen		0.0	.;.;B;B;B
Vest4		0.35, 0.34
MutPred		0.56		Gain of phosphorylation at N7 (P = 0.082);Gain of phosphorylation at N7 (P = 0.082);Gain of phosphorylation at N7 (P = 0.082);Gain of phosphorylation at N7 (P = 0.082);Gain of phosphorylation at N7 (P = 0.082);
MVP		0.60
MPC		1.8
ClinPred		0.74	D
GERP RS		4.7
Varity_R		0.30
gMVP		0.81

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: chr2-28975010;