NM_000543.5:c.1451C>T

Variant names:

• chr11-6394006-C-T
• rs267607075
• NM_000543.5:c.1451C>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Moderate

The NM_000543.5(SMPD1):​c.1451C>T​(p.Ala484Val) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A484E) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SMPD1 NM_000543.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.67
• Publications: 10 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 10 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain in NM_000543.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-6394006-C-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 2995.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.887
• PP5: Variant 11-6394006-C-T is Pathogenic according to our data. Variant chr11-6394006-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 2136993.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000543.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMPD1	NM_000543.5	MANE Select	c.1451C>T	p.Ala484Val	missense	Exon 5 of 6	NP_000534.3
	SMPD1	NM_001007593.3		c.1448C>T	p.Ala483Val	missense	Exon 5 of 6	NP_001007594.2
	SMPD1	NM_001365135.2		c.1319C>T	p.Ala440Val	missense	Exon 4 of 5	NP_001352064.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMPD1	ENST00000342245.9	TSL:1 MANE Select	c.1451C>T	p.Ala484Val	missense	Exon 5 of 6	ENSP00000340409.4
	SMPD1	ENST00000526280.1	TSL:1	c.506C>T	p.Ala169Val	missense	Exon 3 of 4	ENSP00000436278.1
	SMPD1	ENST00000531303.5	TSL:1	n.*282C>T		non_coding_transcript_exon	Exon 5 of 6	ENSP00000432625.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461892 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Niemann-Pick disease, type A;C0268243:Niemann-Pick disease, type B (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Benign	23
DANN	Uncertain	1.0
Eigen	Uncertain	0.34
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	D
M_CAP	Uncertain	0.19	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Uncertain	-0.035	T
PhyloP100		4.7
PrimateAI	Uncertain	0.61	T
PROVEAN	Uncertain	-3.2	D
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0060	D
Sift4G	Uncertain	0.013	D
Vest4		0.84
MVP		0.99
MPC		0.73
ClinPred		0.98	D
GERP RS		3.8
Varity_R		0.58
gMVP		0.93
Mutation Taster		=5/95	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: rs267607075; hg19: chr11-6415236;