11-6390614-G-GCGTCACTC

Variant names:

• chr11-6390614-G-GCGTCACTC
• NM_000543.5:c.19_26dupTCACTCCG

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000543.5(SMPD1):​c.19_26dupTCACTCCG​(p.Gln10HisfsTer70) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SMPD1 NM_000543.5 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -0.805
• Publications: 0 publications found

Genes affected

SMPD1 (HGNC:11120): (sphingomyelin phosphodiesterase 1) The protein encoded by this gene is a lysosomal acid sphingomyelinase that converts sphingomyelin to ceramide. The encoded protein also has phospholipase C activity. Defects in this gene are a cause of Niemann-Pick disease type A (NPA) and Niemann-Pick disease type B (NPB). Multiple transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2010]

SMPD1 Gene-Disease associations (from GenCC):

• acid sphingomyelinase deficiency

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Niemann-Pick disease

  Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
• Niemann-Pick disease type A

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
• Niemann-Pick disease type B

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 379 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-6390614-G-GCGTCACTC is Pathogenic according to our data. Variant chr11-6390614-G-GCGTCACTC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2679040.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMPD1	NM_000543.5	c.19_26dupTCACTCCG	p.Gln10HisfsTer70	frameshift_variant	Exon 1 of 6	ENST00000342245.9	NP_000534.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMPD1	ENST00000342245.9	c.19_26dupTCACTCCG	p.Gln10HisfsTer70	frameshift_variant	Exon 1 of 6	1	NM_000543.5	ENSP00000340409.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Niemann-Pick disease, type A Pathogenic:1

May 25, 2023

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.81

Splicing

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

Other links and lift over

hg19: chr11-6411844;