2-28783934-A-C

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM2PM5PP2PP5_Very_Strong

The NM_002709.3(PPP1CB):​c.548A>C​(p.Glu183Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E183V) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 32)

Consequence

PPP1CB
NM_002709.3 missense

Scores

5
7
7

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 9.29
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 13 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-28783934-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 254651.Status of the report is criteria_provided_single_submitter, 1 stars.
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.
PP5
Variant 2-28783934-A-C is Pathogenic according to our data. Variant chr2-28783934-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 254652.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-28783934-A-C is described in Lovd as [Likely_pathogenic]. Variant chr2-28783934-A-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
PPP1CBNM_002709.3 linkuse as main transcriptc.548A>C p.Glu183Ala missense_variant 5/8 ENST00000395366.3
PPP1CBNM_206876.2 linkuse as main transcriptc.548A>C p.Glu183Ala missense_variant 6/9

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
PPP1CBENST00000395366.3 linkuse as main transcriptc.548A>C p.Glu183Ala missense_variant 5/81 NM_002709.3 P1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
Cov.:
29
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingInvitaeDec 11, 2023This sequence change replaces glutamic acid, which is acidic and polar, with alanine, which is neutral and non-polar, at codon 183 of the PPP1CB protein (p.Glu183Ala). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of Noonan syndrome (PMID: 27681385, 30236064). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 254652). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt PPP1CB protein function with a negative predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingGeneDxAug 08, 2021Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 27681385, 30236064) -
Noonan syndrome-like disorder with loose anagen hair 2 Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMMay 31, 2017- -
Cardiovascular phenotype Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingAmbry GeneticsMar 30, 2021The c.548A>C (p.E183A) alteration is located in exon 5 (coding exon 5) of the PPP1CB gene. This alteration results from an A to C substitution at nucleotide position 548, causing the glutamic acid (E) at amino acid position 183 to be replaced by an alanine (A). Based on data from the Genome Aggregation Database (gnomAD), the PPP1CB c.548A>C alteration was not observed, with coverage at this position. This alteration has been previously reported in multiple patients with various phenotypes suggestive of Noonan syndrome including global developmental delay, macrocephaly, seizures, congenital heart defects, and dysmorphic features (Ma, 2016; Lin, 2018; Hong 2020). In addition, another alteration affecting the same amino acid, p.E183V, was reported in a patient with a similar neurodevelopmental disorder (Ma, 2016). The p.E183 amino acid is conserved in available vertebrate species. This missense alteration is located in a region that has a low rate of benign missense variation (Lek, 2016; Firth, 2009). The p.E183A alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, this alteration is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.81
BayesDel_addAF
Uncertain
0.060
T
BayesDel_noAF
Benign
-0.15
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.80
.;D;D;D
Eigen
Uncertain
0.26
Eigen_PC
Uncertain
0.44
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.94
D;D;.;.
M_CAP
Benign
0.027
D
MetaRNN
Uncertain
0.61
D;D;D;D
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
1.1
.;L;L;L
MutationTaster
Benign
1.0
D;D;D
PrimateAI
Pathogenic
0.88
D
PROVEAN
Pathogenic
-4.7
D;D;D;D
REVEL
Benign
0.28
Sift
Uncertain
0.0010
D;D;D;D
Sift4G
Benign
0.078
T;T;T;T
Polyphen
0.014
.;B;B;B
Vest4
0.92, 0.92
MutPred
0.56
.;Loss of disorder (P = 0.0568);Loss of disorder (P = 0.0568);Loss of disorder (P = 0.0568);
MVP
0.81
MPC
2.2
ClinPred
0.98
D
GERP RS
5.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.64
gMVP
0.95

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs886037954; hg19: chr2-29006800; API