NM_006306.4:c.616-6G>A

Variant names:

• chrX-53413144-C-T
• rs587784424
• NM_006306.4:c.616-6G>A

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BS1 BS2

The NM_006306.4(SMC1A):​c.616-6G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000246 in 1,210,012 control chromosomes in the GnomAD database, including 2 homozygotes. There are 167 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00012 (0 hom., 7 hem., cov: 23)
  • Exomes 𝑓: 0.00026 (2 hom. 160 hem.)
• Consequence: SMC1A NM_006306.4 splice_region, intron
• Scores: Splicing: ADA: 0.000007797
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4
• Conservation: PhyloP100: -0.00400
• Publications: 0 publications found

Genes affected

SMC1A (HGNC:11111): (structural maintenance of chromosomes 1A) Proper cohesion of sister chromatids is a prerequisite for the correct segregation of chromosomes during cell division. The cohesin multiprotein complex is required for sister chromatid cohesion. This complex is composed partly of two structural maintenance of chromosomes (SMC) proteins, SMC3 and either SMC1B or the protein encoded by this gene. Most of the cohesin complexes dissociate from the chromosomes before mitosis, although those complexes at the kinetochore remain. Therefore, the encoded protein is thought to be an important part of functional kinetochores. In addition, this protein interacts with BRCA1 and is phosphorylated by ATM, indicating a potential role for this protein in DNA repair. This gene, which belongs to the SMC gene family, is located in an area of the X-chromosome that escapes X inactivation. Mutations in this gene result in Cornelia de Lange syndrome. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2013]

SMC1A Gene-Disease associations (from GenCC):

• Cornelia de Lange syndrome 2

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• developmental and epileptic encephalopathy, 85, with or without midline brain defects

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• X-linked complex neurodevelopmental disorder

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• atypical Rett syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Cornelia de Lange syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Benign. The variant received -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.73).
• BP6: Variant X-53413144-C-T is Benign according to our data. Variant chrX-53413144-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 159963.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.000116 (13/111895) while in subpopulation SAS AF = 0.00485 (13/2680). AF 95% confidence interval is 0.00287. There are 0 homozygotes in GnomAd4. There are 7 alleles in the male GnomAd4 subpopulation. Median coverage is 23. This position passed quality control check.
• BS2: High AC in GnomAd4 at 13 AD,XL gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006306.4. 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
	SMC1A	NM_006306.4	MANE Select	c.616-6G>A		splice_region intron	N/A	NP_006297.2
	SMC1A	NM_001281463.1		c.550-6G>A		splice_region intron	N/A	NP_001268392.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMC1A	ENST00000322213.9	TSL:1 MANE Select	c.616-6G>A		splice_region intron	N/A	ENSP00000323421.3
	SMC1A	ENST00000375340.10	TSL:1	c.550-6G>A		splice_region intron	N/A	ENSP00000364489.7
	SMC1A	ENST00000675504.1		c.550-6G>A		splice_region intron	N/A	ENSP00000502524.1

Frequencies

GnomAD3 genomes AF: 0.000116 AC: 13 AN: 111840 Hom.: 0 Cov.: 23

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00484

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000478 AC: 87 AN: 181875 AF XY: 0.000670

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000260 AC: 285 AN: 1098117 Hom.: 2 Cov.: 32 AF XY: 0.000440 AC XY: 160 AN XY: 363475

African (AFR) AF: 0.00 AC: 0 AN: 26402

American (AMR) AF: 0.00 AC: 0 AN: 35203

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19386

East Asian (EAS) AF: 0.00 AC: 0 AN: 30206

South Asian (SAS) AF: 0.00512 AC: 277 AN: 54141

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40496

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4136

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 842055

Other (OTH) AF: 0.000174 AC: 8 AN: 46092

GnomAD4 genome AF: 0.000116 AC: 13 AN: 111895 Hom.: 0 Cov.: 23 AF XY: 0.000205 AC XY: 7 AN XY: 34073

African (AFR) AF: 0.00 AC: 0 AN: 30815

American (AMR) AF: 0.00 AC: 0 AN: 10478

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2646

East Asian (EAS) AF: 0.00 AC: 0 AN: 3550

South Asian (SAS) AF: 0.00485 AC: 13 AN: 2680

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 6072

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 218

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 53221

Other (OTH) AF: 0.00 AC: 0 AN: 1530

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000227

ClinVar

ClinVar submissions as Germline

Significance: Benign/Likely benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Congenital muscular hypertrophy-cerebral syndrome (1)
-	-	1	Congenital muscular hypertrophy-cerebral syndrome;C5393312:Developmental and epileptic encephalopathy, 85, with or without midline brain defects (1)
-	-	1	not provided (1)
-	-	1	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.73
CADD	Benign	5.2
DANN	Benign	0.61
PhyloP100		-0.0040
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=95/5	polymorphism (auto)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0000078
dbscSNV1_RF	Benign	0.0040
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

dbSNP: rs587784424; hg19: chrX-53440094;