rs120074127

Positions:

• chr11-6393680-C-G
• chr11-6393680-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000543.5(SMPD1):​c.1327C>G​(p.Arg443Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000248 in 1,613,532 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R443L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: SMPD1 NM_000543.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.51

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000543.5
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMPD1	NM_000543.5	c.1327C>G	p.Arg443Gly	missense_variant	4/6	ENST00000342245.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMPD1	ENST00000342245.9	c.1327C>G	p.Arg443Gly	missense_variant	4/6	1	NM_000543.5	P3

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152100 Hom.: 0 Cov.: 32

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: 0.000283

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000562 AC: 14 AN: 249046 Hom.: 0 AF XY: 0.0000668 AC XY: 9 AN XY: 134804

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.000554

Gnomad NFE exome AF: 0.0000180

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000253 AC: 37 AN: 1461432 Hom.: 0 Cov.: 30 AF XY: 0.0000289 AC XY: 21 AN XY: 727082

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.000487

Gnomad4 NFE exome AF: 0.00000900

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152100 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74296

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.000283

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.00000992 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000576 AC: 7

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.040
CADD	Uncertain	24
DANN	Uncertain	0.99
Eigen	Benign	0.042
Eigen_PC	Benign	-0.0044
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Uncertain	0.20	D
MetaRNN	Uncertain	0.50	T;T
MetaSVM	Uncertain	0.54	D
MutationTaster	Benign	0.62	N;N;N;N
PrimateAI	Benign	0.35	T
PROVEAN	Uncertain	-3.5	D;D
REVEL	Uncertain	0.57
Sift	Uncertain	0.010	D;D
Sift4G	Benign	0.095	T;T
Vest4		0.64
MVP		0.97
MPC		0.68
ClinPred		0.43	T
GERP RS		1.6
Varity_R		0.40
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs120074127; hg19: chr11-6414910;