chr2-216414705-A-G

Variant names:

• chr2-216414705-A-G
• NM_014140.4:c.1A>G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PVS1_Supporting PM2

The NM_014140.4(SMARCAL1):​c.1A>G​(p.Met1?) variant causes a start lost change. The variant allele was found at a frequency of 0.000000684 in 1,461,676 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SMARCAL1 NM_014140.4 start_lost
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 6.60

Genes affected

SMARCAL1 (HGNC:11102): (SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a like 1) The protein encoded by this gene is a member of the SWI/SNF family of proteins. Members of this family have helicase and ATPase activities and are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. The encoded protein shows sequence similarity to the E. coli RNA polymerase-binding protein HepA. Mutations in this gene are a cause of Schimke immunoosseous dysplasia (SIOD), an autosomal recessive disorder with the diagnostic features of spondyloepiphyseal dysplasia, renal dysfunction, and T-cell immunodeficiency. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PVS1: Start lost variant, no pathogenic variants between lost start and next in-frame start position. Next in-frame start position is after 104 codons. Genomic position: 216415014. Lost 0.108 part of the original CDS.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMARCAL1	NM_014140.4	c.1A>G	p.Met1?	start_lost	Exon 3 of 18	ENST00000357276.9	NP_054859.2
SMARCAL1	NM_001127207.2	c.1A>G	p.Met1?	start_lost	Exon 3 of 18		NP_001120679.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMARCAL1	ENST00000357276.9	c.1A>G	p.Met1?	start_lost	Exon 3 of 18	2	NM_014140.4	ENSP00000349823.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461676 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727162

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

SMARCAL1-related disorder Uncertain:1

Nov 04, 2023

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The SMARCAL1 c.1A>G variant is predicted to disrupt the translation initiation site (p.Met1?). To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. An alternative variant at this start codon c.3G>A (p.Met1?) has been reported in compound heterozygous state in patient with Schimke immuno-osseous dysplasia (Yue et al. 2010. PubMed ID: 20179009). Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.26	T;T;.;T;T;.
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D;.;D;.;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D
MetaSVM	Pathogenic	0.90	D
PROVEAN	Uncertain	-3.7	D;N;D;D;N;D
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D;D;D;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;.;D;D
Polyphen		0.98	.;D;.;.;D;.
Vest4		0.90, 0.89
MutPred		0.99		Loss of glycosylation at P4 (P = 0.129);Loss of glycosylation at P4 (P = 0.129);Loss of glycosylation at P4 (P = 0.129);Loss of glycosylation at P4 (P = 0.129);Loss of glycosylation at P4 (P = 0.129);Loss of glycosylation at P4 (P = 0.129);
MVP		0.96
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.78
gMVP		0.57

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-217279428;