chr6-122795812-C-T

Variant names:

• chr6-122795812-C-T
• rs150400180
• NM_006714.5:c.248C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_006714.5(SMPDL3A):​c.248C>T​(p.Ser83Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,926 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 Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SMPDL3A NM_006714.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.50
• Publications: 0 publications found

Genes affected

SMPDL3A (HGNC:17389): (sphingomyelin phosphodiesterase acid like 3A) Enables phosphoric diester hydrolase activity and zinc ion binding activity. Involved in nucleoside triphosphate catabolic process. Located in extracellular space. [provided by Alliance of Genome Resources, Apr 2022]

SMPDL3A Gene-Disease associations (from GenCC):

• sensory peripheral neuropathy

  Inheritance: AR Classification: LIMITED Submitted by: PanelApp Australia

ENSG00000294893 (HGNC:):

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.94

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006714.5. 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
	SMPDL3A	NM_006714.5	MANE Select	c.248C>T	p.Ser83Phe	missense	Exon 2 of 8	NP_006705.1	Q92484-1
	SMPDL3A	NM_001286138.2		c.-67-1012C>T		intron	N/A	NP_001273067.1	Q92484-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMPDL3A	ENST00000368440.5	TSL:1 MANE Select	c.248C>T	p.Ser83Phe	missense	Exon 2 of 8	ENSP00000357425.4	Q92484-1
	SMPDL3A	ENST00000894537.1		c.248C>T	p.Ser83Phe	missense	Exon 2 of 7	ENSP00000564596.1
	SMPDL3A	ENST00000894534.1		c.248C>T	p.Ser83Phe	missense	Exon 2 of 6	ENSP00000564593.1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152118 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000724

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: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251416 AF XY: 0.00000736

Gnomad AFR exome AF: 0.000123

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461808 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727212

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000597 AC: 2 AN: 33480

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111952

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152118 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74316

African (AFR) AF: 0.0000724 AC: 3 AN: 41412

American (AMR) AF: 0.00 AC: 0 AN: 15276

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5188

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10602

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68024

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.0000264 Hom.: 0

Bravo AF: 0.0000302

ESP6500AA AF: 0.000681 AC: 3

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.0000165 AC: 2

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.73	D
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.93	D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.5	M
PhyloP100		7.5
PrimateAI	Uncertain	0.60	T
PROVEAN	Pathogenic	-4.5	D
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.92
MVP		0.98
MPC		0.49
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.99
gMVP		0.95
Mutation Taster		=10/90	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: rs150400180; hg19: chr6-123116957;