6-131890340-G-C

Variant names:

• chr6-131890340-G-C
• rs149828062
• NM_006208.3:c.2608-1G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_006208.3(ENPP1):​c.2608-1G>C variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,354 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ENPP1 NM_006208.3 splice_acceptor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.60
• Publications: 0 publications found

Genes affected

ENPP1 (HGNC:3356): (ectonucleotide pyrophosphatase/phosphodiesterase 1) This gene is a member of the ecto-nucleotide pyrophosphatase/phosphodiesterase (ENPP) family. The encoded protein is a type II transmembrane glycoprotein comprising two identical disulfide-bonded subunits. This protein has broad specificity and cleaves a variety of substrates, including phosphodiester bonds of nucleotides and nucleotide sugars and pyrophosphate bonds of nucleotides and nucleotide sugars. This protein may function to hydrolyze nucleoside 5' triphosphates to their corresponding monophosphates and may also hydrolyze diadenosine polyphosphates. Mutations in this gene have been associated with 'idiopathic' infantile arterial calcification, ossification of the posterior longitudinal ligament of the spine (OPLL), and insulin resistance. [provided by RefSeq, Jul 2008]

ENPP1 Gene-Disease associations (from GenCC):

• arterial calcification, generalized, of infancy, 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen
• hypopigmentation-punctate palmoplantar keratoderma syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: ClinGen, G2P, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• hypophosphatemic rickets, autosomal recessive, 2

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• arterial calcification of infancy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive hypophosphatemic rickets

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive inherited pseudoxanthoma elasticum

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 1.7332613 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.1, offset of 50, new splice context is: gaattgttaatgttacacAGagc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006208.3. 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
	ENPP1	NM_006208.3	MANE Select	c.2608-1G>C		splice_acceptor intron	N/A	NP_006199.2	P22413

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ENPP1	ENST00000647893.1	MANE Select	c.2608-1G>C		splice_acceptor intron	N/A	ENSP00000498074.1	P22413
	ENPP1	ENST00000922186.1		c.2476-1G>C		splice_acceptor intron	N/A	ENSP00000592245.1
	ENPP1	ENST00000513998.5	TSL:5	n.*1445-1G>C		splice_acceptor intron	N/A	ENSP00000422424.1	E9PE72

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460354 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726648

African (AFR) AF: 0.00 AC: 0 AN: 33458

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1110602

Other (OTH) AF: 0.00 AC: 0 AN: 60350

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.050
CADD	Pathogenic	26
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.6
GERP RS		5.7
Mutation Taster		=6/94	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.96
SpliceAI score (max)		0.81		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.81		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs149828062; hg19: chr6-132211480;