9-22006018-G-C

Position:

• chr9-22006018-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_004936.4(CDKN2B):​c.386C>G​(p.Ala129Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,451,234 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CDKN2B NM_004936.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0320

Genes affected

CDKN2B (HGNC:1788): (cyclin dependent kinase inhibitor 2B) This gene lies adjacent to the tumor suppressor gene CDKN2A in a region that is frequently mutated and deleted in a wide variety of tumors. This gene encodes a cyclin-dependent kinase inhibitor, which forms a complex with CDK4 or CDK6, and prevents the activation of the CDK kinases, thus the encoded protein functions as a cell growth regulator that controls cell cycle G1 progression. The expression of this gene was found to be dramatically induced by TGF beta, which suggested its role in the TGF beta induced growth inhibition. Two alternatively spliced transcript variants of this gene, which encode distinct proteins, have been reported. [provided by RefSeq, Jul 2008]

CDKN2B-AS1 (HGNC:34341): (CDKN2B antisense RNA 1) This gene is located within the CDKN2B-CDKN2A gene cluster at chromosome 9p21. The gene product is a functional RNA molecule that interacts with polycomb repressive complex-1 (PRC1) and -2 (PRC2), leading to epigenetic silencing of other genes in this cluster. This region is a significant genetic susceptibility locus for cardiovascular disease, and has also been linked to a number of other pathologies, including several cancers, intracranial aneurysm, type-2 diabetes, periodontitis, Alzheimer's disease, endometriosis, frailty in the elderly, and glaucoma. Multiple alternatively processed transcript variants have been detected, some of which may take the form of circular RNA molecules (PMID:21151960). [provided by RefSeq, May 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.21209195).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CDKN2B	NM_004936.4	c.386C>G	p.Ala129Gly	missense_variant	2/2	ENST00000276925.7
CDKN2B-AS1	NR_003529.3	n.371+10857G>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CDKN2B	ENST00000276925.7	c.386C>G	p.Ala129Gly	missense_variant	2/2	1	NM_004936.4	P1
CDKN2B-AS1	ENST00000650946.1	n.29+10857G>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000429 AC: 1 AN: 233322 Hom.: 0 AF XY: 0.00000776 AC XY: 1 AN XY: 128894

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000293

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.89e-7 AC: 1 AN: 1451234 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 722364

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Jul 26, 2021

The c.386C>G (p.A129G) alteration is located in exon 2 (coding exon 2) of the CDKN2B gene. This alteration results from a C to G substitution at nucleotide position 386, causing the alanine (A) at amino acid position 129 to be replaced by a glycine (G). 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	Benign	0.22
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	10
DANN	Benign	0.92
DEOGEN2	Uncertain	0.67	D
Eigen	Benign	-0.80
Eigen_PC	Benign	-0.86
FATHMM_MKL	Benign	0.19	N
LIST_S2	Benign	0.76	T
M_CAP	Benign	0.059	D
MetaRNN	Benign	0.21	T
MetaSVM	Benign	-0.73	T
MutationAssessor	Uncertain	2.6	M
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.35	T
PROVEAN	Uncertain	-2.6	D
REVEL	Benign	0.15
Sift	Uncertain	0.013	D
Sift4G	Benign	0.087	T
Polyphen		0.0040	B
Vest4		0.19
MutPred		0.51		Gain of disorder (P = 0.0772);
MVP		0.78
MPC		0.40
ClinPred		0.28	T
GERP RS		2.9
Varity_R		0.14
gMVP		0.65

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: rs1253220031; hg19: chr9-22006017;