2-44201612-T-C

Variant summary

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

The NM_002706.6(PPM1B):c.413T>C(p.Met138Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: PPM1B NM_002706.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.02

Genes affected

PPM1B (HGNC:9276): (protein phosphatase, Mg2+/Mn2+ dependent 1B) The protein encoded by this gene is a member of the PP2C family of Ser/Thr protein phosphatases. PP2C family members are known to be negative regulators of cell stress response pathways. This phosphatase has been shown to dephosphorylate cyclin-dependent kinases (CDKs), and thus may be involved in cell cycle control. Overexpression of this phosphatase is reported to cause cell-growth arrest or cell death. Alternative splicing results in multiple transcript variants encoding different isoforms. Additional transcript variants have been described, but currently do not represent full-length sequences. [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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PPM1B	NM_002706.6	c.413T>C	p.Met138Thr	missense_variant	2/6	ENST00000282412.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PPM1B	ENST00000282412.9	c.413T>C	p.Met138Thr	missense_variant	2/6	1	NM_002706.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000120 AC: 3 AN: 250980 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135600

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.0000994

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461878 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727240

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.000115

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

EpiCase AF: 0.0000545

EpiControl AF: 0.00

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

Jun 16, 2023

The c.413T>C (p.M138T) alteration is located in exon 2 (coding exon 1) of the PPM1B gene. This alteration results from a T to C substitution at nucleotide position 413, causing the methionine (M) at amino acid position 138 to be replaced by a threonine (T). 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	Pathogenic	0.87
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.30
Cadd	Uncertain	24
Dann	Uncertain	0.99
Eigen	Uncertain	0.21
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.93	D;D;D;D;D
M_CAP	Benign	0.0093	T
MetaRNN	Uncertain	0.67	D;D;D;D;D
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Uncertain	-3.0	D;D;D;D;D
REVEL	Uncertain	0.31
Sift	Uncertain	0.0030	D;D;D;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D
Polyphen		0.0070, 0.042	.;.;B;B;.
Vest4		0.57, 0.61, 0.58
MutPred		0.73		Gain of glycosylation at M138 (P = 0.0565);Gain of glycosylation at M138 (P = 0.0565);Gain of glycosylation at M138 (P = 0.0565);Gain of glycosylation at M138 (P = 0.0565);Gain of glycosylation at M138 (P = 0.0565);
MVP		0.61
MPC		0.26
ClinPred		0.74	D
GERP RS		5.7
Varity_R		0.81
gMVP		0.78

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1417171158; hg19: chr2-44428751;