9-21971161-G-C

Variant names:

• chr9-21971161-G-C
• rs374984975
• NM_000077.5:c.198C>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM1 BS2

The NM_000077.5(CDKN2A):​c.198C>G​(p.His66Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000624 in 1,442,770 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H66R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: CDKN2A NM_000077.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:6
• Conservation: PhyloP100: 0.306
• Publications: 7 publications found

Genes affected

CDKN2A (HGNC:1787): (cyclin dependent kinase inhibitor 2A) This gene generates several transcript variants which differ in their first exons. At least three alternatively spliced variants encoding distinct proteins have been reported, two of which encode structurally related isoforms known to function as inhibitors of CDK4 kinase. The remaining transcript includes an alternate first exon located 20 Kb upstream of the remainder of the gene; this transcript contains an alternate open reading frame (ARF) that specifies a protein which is structurally unrelated to the products of the other variants. This ARF product functions as a stabilizer of the tumor suppressor protein p53 as it can interact with, and sequester, the E3 ubiquitin-protein ligase MDM2, a protein responsible for the degradation of p53. In spite of the structural and functional differences, the CDK inhibitor isoforms and the ARF product encoded by this gene, through the regulatory roles of CDK4 and p53 in cell cycle G1 progression, share a common functionality in cell cycle G1 control. This gene is frequently mutated or deleted in a wide variety of tumors, and is known to be an important tumor suppressor gene. [provided by RefSeq, Sep 2012]

CDKN2A Gene-Disease associations (from GenCC):

• melanoma, cutaneous malignant, susceptibility to, 2

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• melanoma-pancreatic cancer syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen, Ambry Genetics
• familial atypical multiple mole melanoma syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• melanoma and neural system tumor syndrome

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ENSG00000264545 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM1: In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 43 uncertain in NM_000077.5
• BS2: High AC in GnomAdExome4 at 9 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000077.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CDKN2A	NM_000077.5	MANE Select	c.198C>G	p.His66Gln	missense	Exon 2 of 3	NP_000068.1	P42771-1
	CDKN2A	NM_058195.4	MANE Plus Clinical	c.241C>G	p.Arg81Gly	missense	Exon 2 of 3	NP_478102.2	Q8N726-1
	CDKN2A	NM_001195132.2		c.198C>G	p.His66Gln	missense	Exon 2 of 4	NP_001182061.1	P42771-4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CDKN2A	ENST00000304494.10	TSL:1 MANE Select	c.198C>G	p.His66Gln	missense	Exon 2 of 3	ENSP00000307101.5	P42771-1
	CDKN2A	ENST00000579755.2	TSL:1 MANE Plus Clinical	c.241C>G	p.Arg81Gly	missense	Exon 2 of 3	ENSP00000462950.1	Q8N726-1
	CDKN2A	ENST00000498124.1	TSL:1	c.198C>G	p.His66Gln	missense	Exon 2 of 4	ENSP00000418915.1	P42771-4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000467 AC: 1 AN: 214172 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000105

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000624 AC: 9 AN: 1442770 Hom.: 0 Cov.: 31 AF XY: 0.00000975 AC XY: 7 AN XY: 717830

African (AFR) AF: 0.00 AC: 0 AN: 33284

American (AMR) AF: 0.00 AC: 0 AN: 44168

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25986

East Asian (EAS) AF: 0.00 AC: 0 AN: 39328

South Asian (SAS) AF: 0.00 AC: 0 AN: 85596

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 39550

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5438

European-Non Finnish (NFE) AF: 0.00000811 AC: 9 AN: 1109528

Other (OTH) AF: 0.00 AC: 0 AN: 59892

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000840 AC: 1

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	2	-	Hereditary cancer-predisposing syndrome (2)
-	1	-	Familial melanoma (1)
-	1	-	Melanoma and neural system tumor syndrome;C1835044:Melanoma, cutaneous malignant, susceptibility to, 2;C1838547:Melanoma-pancreatic cancer syndrome (1)
-	1	-	not provided (1)
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.41
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Benign	-0.12
CADD	Benign	19
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.44	T
Eigen	Uncertain	0.32
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.62	T
M_CAP	Uncertain	0.18	D
MetaRNN	Uncertain	0.44	T
MetaSVM	Uncertain	0.20	D
PhyloP100		0.31
PrimateAI	Uncertain	0.56	T
PROVEAN	Uncertain	-3.2	D
REVEL	Pathogenic	0.67
Sift	Benign	0.46	T
Sift4G	Benign	0.45	T
Polyphen		0.97	D
Vest4		0.22
MutPred		0.56		Gain of catalytic residue at H66 (P = 0.0464)
MVP		0.99
MPC		0.62
ClinPred		0.69	D
GERP RS		4.9
PromoterAI		-0.0057	Neutral
Varity_R		0.19
gMVP		0.73
Mutation Taster		=10/90	disease causing

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

Other links and lift over

dbSNP: rs374984975; hg19: chr9-21971160;