5-146600439-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP2 PP3

The NM_181675.4(PPP2R2B):c.812C>G(p.Pro271Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,461,450 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: PPP2R2B NM_181675.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 10.0

Genes affected

PPP2R2B (HGNC:9305): (protein phosphatase 2 regulatory subunit Bbeta) The product of this gene belongs to the phosphatase 2 regulatory subunit B family. Protein phosphatase 2 is one of the four major Ser/Thr phosphatases, and it is implicated in the negative control of cell growth and division. It consists of a common heteromeric core enzyme, which is composed of a catalytic subunit and a constant regulatory subunit, that associates with a variety of regulatory subunits. The B regulatory subunit might modulate substrate selectivity and catalytic activity. This gene encodes a beta isoform of the regulatory subunit B55 subfamily. Defects in this gene cause autosomal dominant spinocerebellar ataxia 12 (SCA12), a disease caused by degeneration of the cerebellum, sometimes involving the brainstem and spinal cord, and in resulting in poor coordination of speech and body movements. Multiple alternatively spliced variants, which encode different isoforms, have been identified for this gene. The 5' UTR of some of these variants includes a CAG trinucleotide repeat sequence (7-28 copies) that can be expanded to 55-78 copies in cases of SCA12. [provided by RefSeq, Jul 2016]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PP2: Missense variant where missense usually causes diseases, PPP2R2B
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.796

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PPP2R2B	NM_181675.4	c.812C>G	p.Pro271Arg	missense_variant	8/10	ENST00000394411.9
CTB-99A3.1	XR_007058986.1	n.229-6530G>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PPP2R2B	ENST00000394411.9	c.812C>G	p.Pro271Arg	missense_variant	8/10	2	NM_181675.4	P3
	ENST00000512730.1	n.247-6530G>C		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1461450 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727032

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000282 Hom.: 0

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

Jan 23, 2023

The c.821C>G (p.P274R) alteration is located in exon 7 (coding exon 7) of the PPP2R2B gene. This alteration results from a C to G substitution at nucleotide position 821, causing the proline (P) at amino acid position 274 to be replaced by an arginine (R). 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	0.91
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.16
Cadd	Pathogenic	33
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.54	D;.;.;D;.;.;.;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.80	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.36	D
MutationAssessor	Pathogenic	3.2	M;.;.;M;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.82	D
REVEL	Uncertain	0.56
Sift4G	Uncertain	0.042	D;D;D;D;D;D;D;D
Polyphen		0.98	D;.;B;D;.;P;D;D
Vest4		0.73
MutPred		0.39		Loss of glycosylation at P271 (P = 0.0238);.;.;Loss of glycosylation at P271 (P = 0.0238);.;.;.;.;
MVP		0.76
MPC		1.6
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.88
gMVP		0.53

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

Other links and lift over

dbSNP: rs1267137525; hg19: chr5-145980002;