X-53382363-G-C

Variant names:

• chrX-53382363-G-C
• rs797045994
• NM_006306.4:c.3306C>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_006306.4(SMC1A):​c.3306C>G​(p.Asn1102Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N1102S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 22)
• Consequence: SMC1A NM_006306.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.65
• 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMC1A	NM_006306.4	c.3306C>G	p.Asn1102Lys	missense_variant	Exon 22 of 25	ENST00000322213.9	NP_006297.2
SMC1A	NM_001281463.1	c.3240C>G	p.Asn1080Lys	missense_variant	Exon 23 of 26		NP_001268392.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMC1A	ENST00000322213.9	c.3306C>G	p.Asn1102Lys	missense_variant	Exon 22 of 25	1	NM_006306.4	ENSP00000323421.3

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Dec 11, 2014

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Benign	-0.088	T
BayesDel_noAF	Benign	-0.36
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.50	D;T
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Pathogenic	0.51	D
MetaRNN	Uncertain	0.55	D;D
MetaSVM	Uncertain	0.033	D
MutationAssessor	Uncertain	2.6	M;.
PhyloP100		1.6
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-5.6	D;.
REVEL	Uncertain	0.55
Sift	Uncertain	0.017	D;.
Sift4G	Uncertain	0.0030	D;D
Polyphen		1.0	D;.
Vest4		0.43
MutPred		0.65		Gain of ubiquitination at N1102 (P = 0.0128);.;
MVP		0.94
MPC		3.0
ClinPred		0.99	D
GERP RS		1.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7
Varity_R		0.73
gMVP		0.97
Mutation Taster		=35/65	disease causing

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: rs797045994; hg19: chrX-53409284;