rs1556892359

Variant names:

• chrX-53422506-C-T
• rs1556892359
• NM_006306.4:c.95G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2 PP2 PP3_Strong PP5_Moderate

The NM_006306.4(SMC1A):​c.95G>A​(p.Gly32Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 24)
• Consequence: SMC1A NM_006306.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.65

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]

RIBC1 (HGNC:26537): (RIB43A domain with coiled-coils 1)

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the SMC1A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 68 curated pathogenic missense variants (we use a threshold of 10). The gene has 31 curated benign missense variants. Gene score misZ: 6.4479 (above the threshold of 3.09). GenCC associations: The gene is linked to Cornelia de Lange syndrome, X-linked complex neurodevelopmental disorder, atypical Rett syndrome, Cornelia de Lange syndrome 2, developmental and epileptic encephalopathy, 85, with or without midline brain defects.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant X-53422506-C-T is Pathogenic according to our data. Variant chrX-53422506-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 547840.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMC1A	NM_006306.4	c.95G>A	p.Gly32Glu	missense_variant	Exon 1 of 25	ENST00000322213.9	NP_006297.2
SMC1A	NM_001281463.1	c.-118G>A		5_prime_UTR_variant	Exon 1 of 26		NP_001268392.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMC1A	ENST00000322213.9	c.95G>A	p.Gly32Glu	missense_variant	Exon 1 of 25	1	NM_006306.4	ENSP00000323421.3

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 26

GnomAD4 genome Cov.: 24

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital muscular hypertrophy-cerebral syndrome Pathogenic:1

Mar 31, 2016

Mayo Clinic Laboratories, Mayo Clinic

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.71	D
BayesDel_noAF	Pathogenic	0.79
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.72	D
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	3.2	M
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-7.2	D
REVEL	Pathogenic	0.98
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.92		Gain of disorder (P = 0.1606);
MVP		1.0
MPC		3.2
ClinPred		1.0	D
GERP RS		5.1
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.7
Varity_R		0.97
gMVP		1.0

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: rs1556892359; hg19: chrX-53449455;