2-28783931-T-A

Position:

• chr2-28783931-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3 PP5

The NM_002709.3(PPP1CB):​c.545T>A​(p.Met182Lys) 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M182V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PPP1CB NM_002709.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 7.99

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]

SPDYA (HGNC:30613): (speedy/RINGO cell cycle regulator family member A) Enables protein kinase activator activity and protein kinase binding activity. Involved in several processes, including G1/S transition of mitotic cell cycle; positive regulation of cell population proliferation; and positive regulation of protein kinase activity. Located in nucleoplasm. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.806
• PP5: Variant 2-28783931-T-A is Pathogenic according to our data. Variant chr2-28783931-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 974912.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PPP1CB	NM_002709.3	c.545T>A	p.Met182Lys	missense_variant	5/8	ENST00000395366.3
PPP1CB	NM_206876.2	c.545T>A	p.Met182Lys	missense_variant	6/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PPP1CB	ENST00000395366.3	c.545T>A	p.Met182Lys	missense_variant	5/8	1	NM_002709.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Noonan syndrome-like disorder with loose anagen hair 2 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratorio de Biologia Molecular - Genetica, Hospital de Pediatria Garrahan

Aug 28, 2020

This variant is not identified in the databases, including ExAC, 1000genomes, or HGVD. It is described in a family were the mother and three children with Noonan syndrome with loose anagen hair phenotype harbored the variant. The variant c.548A>C (p.Glu183Ala) was previously described as pathogenic. -

Noonan syndrome Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Service de Génétique Moléculaire, Hôpital Robert Debré

-

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 07, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 33491856) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.81	.;D;D;D
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;.;.
M_CAP	Benign	0.058	D
MetaRNN	Pathogenic	0.81	D;D;D;D
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.6	.;M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-4.9	D;D;D;D
REVEL	Uncertain	0.39
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		0.038	.;B;B;B
Vest4		0.88, 0.88
MutPred		0.67		.;Gain of ubiquitination at M182 (P = 0.0289);Gain of ubiquitination at M182 (P = 0.0289);Gain of ubiquitination at M182 (P = 0.0289);
MVP		0.75
MPC		3.7
ClinPred		0.99	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.93
gMVP		1.0

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: chr2-29006797;