X-49191706-C-A

Variant names:

• chrX-49191706-C-A
• NM_003179.3:c.673G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_003179.3(SYP):​c.673G>T​(p.Glu225*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 25)
• Consequence: SYP NM_003179.3 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.82
• Publications: 0 publications found

Genes affected

SYP (HGNC:11506): (synaptophysin) This gene encodes an integral membrane protein of small synaptic vesicles in brain and endocrine cells. The protein also binds cholesterol and is thought to direct targeting of vesicle-associated membrane protein 2 (synaptobrevin) to intracellular compartments. Mutations in this gene are associated with an X-linked form of cognitive disability. [provided by RefSeq, Jul 2017]

SYP Gene-Disease associations (from GenCC):

• intellectual disability, X-linked 96

  Inheritance: XL Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Illumina, PanelApp Australia, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• non-syndromic X-linked intellectual disability

  Inheritance: XL Classification: MODERATE, SUPPORTIVE Submitted by: Orphanet, ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003179.3. 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
	SYP	NM_003179.3	MANE Select	c.673G>T	p.Glu225*	stop_gained	Exon 6 of 7	NP_003170.1	P08247-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYP	ENST00000263233.9	TSL:1 MANE Select	c.673G>T	p.Glu225*	stop_gained	Exon 6 of 7	ENSP00000263233.4	P08247-1
	SYP	ENST00000479808.5	TSL:1	c.673G>T	p.Glu225*	stop_gained	Exon 6 of 6	ENSP00000418169.1	P08247-1
	SYP	ENST00000920145.1		c.661G>T	p.Glu221*	stop_gained	Exon 6 of 6	ENSP00000590204.1

Frequencies

GnomAD3 genomes Cov.: 25

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 25

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	38
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.8
Vest4		0.90
ClinPred		1.0	D
GERP RS		5.5
Mutation Taster		=23/177	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

hg19: chrX-49048163;