6-31860517-CCA-TCT

Variant names:

• chr6-31860517-CCA-TCT
• NM_000434.4:c.718_720delTGGinsAGA
• NEU1 p.Trp240Arg

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PS1 PP2 PP3

The NM_000434.4(NEU1):​c.718_720delTGGinsAGA​(p.Trp240Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Pathogenic in ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NEU1 NM_000434.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.47
• Publications: 0 publications found

Genes affected

NEU1 (HGNC:7758): (neuraminidase 1) The protein encoded by this gene is a lysosomal enzyme that cleaves terminal sialic acid residues from substrates such as glycoproteins and glycolipids. In the lysosome, this enzyme is part of a heterotrimeric complex together with beta-galactosidase and cathepsin A (the latter is also referred to as 'protective protein'). Mutations in this gene can lead to sialidosis, a lysosomal storage disease that can be type 1 (cherry red spot-myoclonus syndrome or normosomatic type), which is late-onset, or type 2 (the dysmorphic type), which occurs at an earlier age with increased severity. [provided by RefSeq, Jul 2008]

NEU1 Gene-Disease associations (from GenCC):

• sialidosis

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• sialidosis type 2

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• congenital sialidosis type 2

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• juvenile sialidosis type 2

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• sialidosis type 1

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

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

• PS1: Transcript NM_000434.4 (NEU1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 24 curated pathogenic missense variants (we use a threshold of 10). The gene has 5 curated benign missense variants. Gene score misZ: 1.4218 (below the threshold of 3.09). Trascript score misZ: 2.2638 (below the threshold of 3.09). GenCC associations: The gene is linked to juvenile sialidosis type 2, sialidosis type 1, sialidosis, sialidosis type 2, congenital sialidosis type 2.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000434.4. 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
	NEU1	NM_000434.4	MANE Select	c.718_720delTGGinsAGA	p.Trp240Arg	missense	N/A	NP_000425.1	Q5JQI0

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NEU1	ENST00000375631.5	TSL:1 MANE Select	c.718_720delTGGinsAGA	p.Trp240Arg	missense	N/A	ENSP00000364782.4	Q99519
	NEU1	ENST00000850553.1		c.712_714delTGGinsAGA	p.Trp238Arg	missense	N/A	ENSP00000520846.1	A0ABB0MVI7
	NEU1	ENST00000877813.1		c.718_720delTGGinsAGA	p.Trp240Arg	missense	N/A	ENSP00000547872.1

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

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.5

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: chr6-31828294;