rs120074126

Variant names:

• chr11-6393620-C-T
• rs120074126
• NM_000543.5:c.1267C>T

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Very_Strong

The NM_000543.5(SMPD1):​c.1267C>T​(p.His423Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.00000372 in 1,611,816 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. H423R) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: SMPD1 NM_000543.5 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:15 O:1
• Conservation: PhyloP100: 7.13
• Publications: 17 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: Orphanet, Genomics England PanelApp, PanelApp Australia, G2P
• Niemann-Pick disease type B

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

ACMG classification

Our verdict: Pathogenic. The variant received 16 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, 4 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 chr11-6393621-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 2136989.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.91
• PP5: Variant 11-6393620-C-T is Pathogenic according to our data. Variant chr11-6393620-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 2992.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMPD1	NM_000543.5	MANE Select	c.1267C>T	p.His423Tyr	missense	Exon 4 of 6	NP_000534.3
	SMPD1	NM_001007593.3		c.1264C>T	p.His422Tyr	missense	Exon 4 of 6	NP_001007594.2	P17405-4
	SMPD1	NM_001365135.2		c.1135C>T	p.His379Tyr	missense	Exon 3 of 5	NP_001352064.1	P17405-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMPD1	ENST00000342245.9	TSL:1 MANE Select	c.1267C>T	p.His423Tyr	missense	Exon 4 of 6	ENSP00000340409.4	P17405-1
	SMPD1	ENST00000526280.1	TSL:1	c.322C>T	p.His108Tyr	missense	Exon 2 of 4	ENSP00000436278.1	H0YEP5
	SMPD1	ENST00000531303.5	TSL:1	n.*98C>T		non_coding_transcript_exon	Exon 4 of 6	ENSP00000432625.1	E9PPK6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152170 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000343 AC: 5 AN: 1459646 Hom.: 0 Cov.: 30 AF XY: 0.00000551 AC XY: 4 AN XY: 726300

African (AFR) AF: 0.00 AC: 0 AN: 33426

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86208

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.000173 AC: 1 AN: 5766

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1109998

Other (OTH) AF: 0.0000166 AC: 1 AN: 60302

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152170 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74330

African (AFR) AF: 0.00 AC: 0 AN: 41432

American (AMR) AF: 0.00 AC: 0 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68024

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00000938 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
5	-	-	Niemann-Pick disease, type A (5)
4	-	-	Niemann-Pick disease, type B (4)
3	-	-	not provided (3)
2	-	-	Niemann-Pick disease, type A;C0268243:Niemann-Pick disease, type B (2)
1	-	-	Sphingomyelin/cholesterol lipidosis (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.64
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Uncertain	25
DANN	Uncertain	1.0
Eigen	Uncertain	0.46
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D
M_CAP	Benign	0.082	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Uncertain	0.15	D
PhyloP100		7.1
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-4.9	D
REVEL	Pathogenic	0.82
Sift	Benign	0.058	T
Sift4G	Benign	0.13	T
Vest4		0.93
MVP		0.96
MPC		0.71
ClinPred		0.98	D
GERP RS		4.8
Varity_R		0.81
gMVP		0.94
Mutation Taster		=4/96	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
Splicevardb		2.0
SpliceAI score (max)		0.030		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: rs120074126; hg19: chr11-6414850;