X-21945025-A-T

Variant names:

• chrX-21945025-A-T
• rs2238958
• NM_004595.5:c.49+4152A>T

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.49+4152A>T 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: 22)
• Consequence: SMS NM_004595.5 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.22
• Publications: 2 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=-0.86).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004595.5. 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
	SMS	NM_004595.5	MANE Select	c.49+4152A>T		intron	N/A	NP_004586.2
	SMS	NM_001258423.2		c.49+4152A>T		intron	N/A	NP_001245352.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMS	ENST00000404933.7	TSL:1 MANE Select	c.49+4152A>T		intron	N/A	ENSP00000385746.2
	SMS	ENST00000457085.2	TSL:5	c.394+3658A>T		intron	N/A	ENSP00000407366.2
	SMS	ENST00000379404.5	TSL:3	c.49+4152A>T		intron	N/A	ENSP00000368714.1

Frequencies

GnomAD3 genomes Cov.: 22

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 22

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
CADD	Benign	0.31
DANN	Benign	0.45
PhyloP100		-1.2

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: rs2238958; hg19: chrX-21963143;