9-21971199-T-G

Variant names:

• chr9-21971199-T-G
• rs201314211
• NM_000077.5:c.160A>C

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM1 BP4_Moderate BS1_Supporting BS2

The NM_000077.5(CDKN2A):​c.160A>C​(p.Met54Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000688 in 1,597,750 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). 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. M54I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CDKN2A NM_000077.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7 B:1
• Conservation: PhyloP100: 2.95
• Publications: 12 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), ClinGen, Ambry Genetics, Genomics England PanelApp
• 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 -5 ACMG points.

• PM1: In a hotspot region, there are 18 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 42 uncertain in NM_000077.5
• BP4: Computational evidence support a benign effect (MetaRNN=0.20295686).
• BS1: Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.0000525 (8/152258) while in subpopulation AMR AF = 0.000457 (7/15302). AF 95% confidence interval is 0.000215. There are 0 homozygotes in GnomAd4. There are 3 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAd4 at 8 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.160A>C	p.Met54Leu	missense	Exon 2 of 3	NP_000068.1	P42771-1
	CDKN2A	NM_058195.4	MANE Plus Clinical	c.203A>C	p.Asp68Ala	missense	Exon 2 of 3	NP_478102.2	Q8N726-1
	CDKN2A	NM_001195132.2		c.160A>C	p.Met54Leu	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.160A>C	p.Met54Leu	missense	Exon 2 of 3	ENSP00000307101.5	P42771-1
	CDKN2A	ENST00000579755.2	TSL:1 MANE Plus Clinical	c.203A>C	p.Asp68Ala	missense	Exon 2 of 3	ENSP00000462950.1	Q8N726-1
	CDKN2A	ENST00000498124.1	TSL:1	c.160A>C	p.Met54Leu	missense	Exon 2 of 4	ENSP00000418915.1	P42771-4

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152140 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000458

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000452 AC: 1 AN: 221122 AF XY: 0.00000813

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000295

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000208 AC: 3 AN: 1445492 Hom.: 0 Cov.: 31 AF XY: 0.00000278 AC XY: 2 AN XY: 719522

African (AFR) AF: 0.00 AC: 0 AN: 33412

American (AMR) AF: 0.0000673 AC: 3 AN: 44584

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26092

East Asian (EAS) AF: 0.00 AC: 0 AN: 39578

South Asian (SAS) AF: 0.00 AC: 0 AN: 85976

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 38932

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5734

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111014

Other (OTH) AF: 0.00 AC: 0 AN: 60170

GnomAD4 genome AF: 0.0000525 AC: 8 AN: 152258 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74450

African (AFR) AF: 0.0000241 AC: 1 AN: 41554

American (AMR) AF: 0.000457 AC: 7 AN: 15302

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5174

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 292

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68002

Other (OTH) AF: 0.00 AC: 0 AN: 2114

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.000117

ExAC AF: 0.00000836 AC: 1

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	1	Hereditary cancer-predisposing syndrome (2)
-	2	-	not provided (2)
-	1	-	Familial melanoma (1)
-	1	-	Melanoma and neural system tumor syndrome (1)
-	1	-	Melanoma-pancreatic cancer syndrome (1)
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Uncertain	0.067	T
BayesDel_noAF	Uncertain	0.030
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Benign	0.13	T
Eigen	Benign	0.071
Eigen_PC	Benign	0.20
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Benign	0.46	T
M_CAP	Uncertain	0.22	D
MetaRNN	Benign	0.20	T
MetaSVM	Benign	-0.62	T
PhyloP100		2.9
PROVEAN	Pathogenic	-5.9	D
REVEL	Pathogenic	0.70
Sift	Uncertain	0.011	D
Sift4G	Uncertain	0.023	D
Vest4		0.29
MVP		1.0
ClinPred		0.95	D
GERP RS		5.8
PromoterAI		-0.041	Neutral
Varity_R		0.59
Mutation Taster		=3/97	disease causing

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

Other links and lift over

dbSNP: rs201314211; hg19: chr9-21971198;