chr18-2707567-C-A

Variant names:

• chr18-2707567-C-A
• NM_015295.3:c.2068C>A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PM5 PP2 PP3_Moderate

The NM_015295.3(SMCHD1):​c.2068C>A​(p.Pro690Thr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P690S) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: SMCHD1 NM_015295.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.67

Genes affected

SMCHD1 (HGNC:29090): (structural maintenance of chromosomes flexible hinge domain containing 1) This gene encodes a protein which contains a hinge region domain found in members of the SMC (structural maintenance of chromosomes) protein family. [provided by RefSeq, Dec 2011]

ENSG00000266049 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr18-2707567-C-T is described in Lovd as [Pathogenic].
• PP2: Missense variant in the SMCHD1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 23 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 3.6318 (above the threshold of 3.09). Trascript score misZ: 3.965 (above the threshold of 3.09). GenCC associations: The gene is linked to facioscapulohumeral muscular dystrophy, arhinia, choanal atresia, and microphthalmia, hyposmia-nasal and ocular hypoplasia-hypogonadotropic hypogonadism syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.855

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMCHD1	NM_015295.3	c.2068C>A	p.Pro690Thr	missense_variant	Exon 16 of 48	ENST00000320876.11	NP_056110.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMCHD1	ENST00000320876.11	c.2068C>A	p.Pro690Thr	missense_variant	Exon 16 of 48	5	NM_015295.3	ENSP00000326603.7

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	24
DANN	Benign	0.94
DEOGEN2	Uncertain	0.72	D
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.86	D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Benign	-0.52	T
MutationAssessor	Uncertain	2.3	M
PrimateAI	Uncertain	0.61	T
PROVEAN	Pathogenic	-5.2	D
REVEL	Uncertain	0.46
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.88
MutPred		0.46		Gain of phosphorylation at P690 (P = 0.0104);
MVP		0.42
MPC		1.8
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.7
Varity_R		0.82
gMVP		0.90

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		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: chr18-2707565;