15-64970159-C-T

Variant names:

• chr15-64970159-C-T
• rs774744618
• NM_016630.7:c.516G>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Moderate BP6_Moderate BP7

The NM_016630.7(SPG21):​c.516G>A​(p.Pro172Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,613,984 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000039 (0 hom.)
• Consequence: SPG21 NM_016630.7 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.338
• Publications: 0 publications found

Genes affected

SPG21 (HGNC:20373): (SPG21 abhydrolase domain containing, maspardin) The protein encoded by this gene binds to the hydrophobic C-terminal amino acids of CD4 which are involved in repression of T cell activation. The interaction with CD4 is mediated by the noncatalytic alpha/beta hydrolase fold domain of this protein. It is thus proposed that this gene product modulates the stimulatory activity of CD4. Mutations in this gene are associated with autosomal recessive spastic paraplegia 21 (SPG21), also known as mast syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2014]

SPG21 Gene-Disease associations (from GenCC):

• mast syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.36).
• BP6: Variant 15-64970159-C-T is Benign according to our data. Variant chr15-64970159-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 409263.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-0.338 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_016630.7. 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
	SPG21	NM_016630.7	MANE Select	c.516G>A	p.Pro172Pro	synonymous	Exon 6 of 9	NP_057714.1
	SPG21	NM_001127889.5		c.516G>A	p.Pro172Pro	synonymous	Exon 6 of 9	NP_001121361.1
	SPG21	NM_001127890.5		c.435G>A	p.Pro145Pro	synonymous	Exon 5 of 8	NP_001121362.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SPG21	ENST00000204566.7	TSL:1 MANE Select	c.516G>A	p.Pro172Pro	synonymous	Exon 6 of 9	ENSP00000204566.2
	SPG21	ENST00000433215.6	TSL:1	c.516G>A	p.Pro172Pro	synonymous	Exon 6 of 9	ENSP00000404111.2
	SPG21	ENST00000416889.6	TSL:2	c.435G>A	p.Pro145Pro	synonymous	Exon 5 of 8	ENSP00000394846.2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152170 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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

GnomAD2 exomes AF: 0.0000557 AC: 14 AN: 251322 AF XY: 0.0000589

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.0000390 AC: 57 AN: 1461814 Hom.: 0 Cov.: 31 AF XY: 0.0000523 AC XY: 38 AN XY: 727210

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: 26134

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39694

South Asian (SAS) AF: 0.000325 AC: 28 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53366

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

European-Non Finnish (NFE) AF: 0.0000216 AC: 24 AN: 1112002

Other (OTH) AF: 0.0000662 AC: 4 AN: 60394

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152170 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74330

African (AFR) AF: 0.0000241 AC: 1 AN: 41432

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

ClinVar submissions as Germline

Significance: Likely benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	Mast syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.080
BayesDel_noAF	Benign	-0.36
CADD	Benign	10
DANN	Benign	0.59
PhyloP100		-0.34
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs774744618; hg19: chr15-65262497; COSMIC: COSV52603205; COSMIC: COSV52603205;