rs104893934

Positions:

• chr5-70942490-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PP3 PP5

The NM_000344.4(SMN1):​c.406C>G​(p.Gln136Glu) variant causes a missense change. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 0)
• Consequence: SMN1 NM_000344.4 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 5.50

Genes affected

SMN1 (HGNC:11117): (survival of motor neuron 1, telomeric) This gene is part of a 500 kb inverted duplication on chromosome 5q13. This duplicated region contains at least four genes and repetitive elements which make it prone to rearrangements and deletions. The repetitiveness and complexity of the sequence have also caused difficulty in determining the organization of this genomic region. The telomeric and centromeric copies of this gene are nearly identical and encode the same protein. However, mutations in this gene, the telomeric copy, are associated with spinal muscular atrophy; mutations in the centromeric copy do not lead to disease. The centromeric copy may be a modifier of disease caused by mutation in the telomeric copy. The critical sequence difference between the two genes is a single nucleotide in exon 7, which is thought to be an exon splice enhancer. Note that the nine exons of both the telomeric and centromeric copies are designated historically as exon 1, 2a, 2b, and 3-8. It is thought that gene conversion events may involve the two genes, leading to varying copy numbers of each gene. The protein encoded by this gene localizes to both the cytoplasm and the nucleus. Within the nucleus, the protein localizes to subnuclear bodies called gems which are found near coiled bodies containing high concentrations of small ribonucleoproteins (snRNPs). This protein forms heteromeric complexes with proteins such as SIP1 and GEMIN4, and also interacts with several proteins known to be involved in the biogenesis of snRNPs, such as hnRNP U protein and the small nucleolar RNA binding protein. Multiple transcript variants encoding distinct isoforms have been described. [provided by RefSeq, Jul 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a mutagenesis_site Impairs binding to substrate containing dimethylated arginine. (size 0) in uniprot entity SMN_HUMAN
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.795
• PP5: Variant 5-70942490-C-G is Pathogenic according to our data. Variant chr5-70942490-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 9180.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr5-70942490-C-G is described in UniProt as null. Variant chr5-70942490-C-G is described in UniProt as null. Variant chr5-70942490-C-G is described in UniProt as null. Variant chr5-70942490-C-G is described in UniProt as null. Variant chr5-70942490-C-G is described in UniProt as null. Variant chr5-70942490-C-G is described in UniProt as null. Variant chr5-70942490-C-G is described in UniProt as null. Variant chr5-70942490-C-G is described in UniProt as null. Variant chr5-70942490-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMN1	NM_000344.4	c.406C>G	p.Gln136Glu	missense_variant	4/9	ENST00000380707.9	NP_000335.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMN1	ENST00000380707.9	c.406C>G	p.Gln136Glu	missense_variant	4/9	1	NM_000344.4	ENSP00000370083	P1

Frequencies

GnomAD3 genomes Cov.: 0

GnomAD4 exome Cov.: 0

GnomAD4 genome Cov.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Werdnig-Hoffmann disease Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jul 13, 2004

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.34
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
CADD	Pathogenic	27
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.62	.;D;.;D;D
Eigen	Benign	0.13
Eigen_PC	Benign	0.16
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.81	T;.;D;D;D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.79	D;D;D;D;D
MetaSVM	Uncertain	0.45	D
MutationTaster	Benign	1.0	A;A;A;A;A
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	-1.5	N;N;N;.;N
REVEL	Pathogenic	0.66
Sift	Benign	0.071	T;T;T;.;T
Sift4G	Benign	0.16	T;T;T;T;T
Vest4		0.57
MutPred		0.64		Gain of disorder (P = 0.1023);Gain of disorder (P = 0.1023);Gain of disorder (P = 0.1023);Gain of disorder (P = 0.1023);Gain of disorder (P = 0.1023);
MVP		0.96
MPC		1.8
ClinPred		0.94	D
GERP RS		3.5
Varity_R		0.61
gMVP		0.75

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

Publications

LitVar

Other links and lift over

dbSNP: rs104893934; hg19: chr5-70238317;