NM_004595.5:c.170+30C>A

Variant names:

• chrX-21967346-C-A
• rs3747276
• NM_004595.5:c.170+30C>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_004595.5(SMS):​c.170+30C>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 21)
• Consequence: SMS NM_004595.5 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.133
• Publications: 8 publications found

Genes affected

SMS (HGNC:11123): (spermine synthase) This gene encodes a protein belonging to the spermidine/spermin synthase family and catalyzes the production of spermine from spermidine. Pseudogenes of this gene are located on chromosomes 1, 5, 6 and X. Mutations in this gene cause an X-linked intellectual disability called Snyder-Robinson Syndrome (SRS). Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2017]

SMS Gene-Disease associations (from GenCC):

• syndromic X-linked intellectual disability Snyder type

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, G2P

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMS	NM_004595.5	c.170+30C>A		intron_variant	Intron 2 of 10	ENST00000404933.7	NP_004586.2
SMS	NM_001258423.2	c.170+30C>A		intron_variant	Intron 2 of 8		NP_001245352.1
SMS	XM_005274582.3	c.68+30C>A		intron_variant	Intron 2 of 10		XP_005274639.1
SMS	XM_011545568.3	c.68+30C>A		intron_variant	Intron 2 of 10		XP_011543870.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMS	ENST00000404933.7	c.170+30C>A		intron_variant	Intron 2 of 10	1	NM_004595.5	ENSP00000385746.2
SMS	ENST00000457085.2	c.515+30C>A		intron_variant	Intron 2 of 5	5		ENSP00000407366.2
SMS	ENST00000379404.5	c.170+30C>A		intron_variant	Intron 2 of 8	3		ENSP00000368714.1
SMS	ENST00000478094.1	n.217+30C>A		intron_variant	Intron 2 of 4	4

Frequencies

GnomAD3 genomes Cov.: 21

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 21

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
CADD	Benign	0.92
DANN	Benign	0.60
PhyloP100		-0.13

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: rs3747276; hg19: chrX-21985464;