6-131851228-AAG-CAA

Variant names:

• chr6-131851228-AAG-CAA
• NM_006208.3:c.517_519delAAGinsCAA
• ENPP1 p.Lys173Gln

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_006208.3(ENPP1):​c.517_519delAAGinsCAA​(p.Lys173Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. The variant is present in control chromosomes in GnomAd MNV project. The variant allele was found at a frequency of 0.0000318 in 1 alleles, including 0 homozygotes. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Benign in ClinVar.

• Frequency: GnomAD MNV: 𝑓 0.000032 Genomes: not found (cov: 32)
• Consequence: ENPP1 NM_006208.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.45
• 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: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 4 uncertain in NM_006208.3

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.517_519delAAGinsCAA	p.Lys173Gln	missense	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.517_519delAAGinsCAA	p.Lys173Gln	missense	N/A	ENSP00000498074.1	P22413
	ENPP1	ENST00000922186.1		c.517_519delAAGinsCAA	p.Lys173Gln	missense	N/A	ENSP00000592245.1
	ENPP1	ENST00000486853.1	TSL:2	n.537_539delAAGinsCAA		non_coding_transcript_exon	Exon 4 of 4

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

GnomAD MNV AF: 0.0000318 AC: 1 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.4

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr6-132172368;