chr18-2700851-C-A

Variant names:

• chr18-2700851-C-A
• NM_015295.3:c.1580C>A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PM5 PP2

The NM_015295.3(SMCHD1):​c.1580C>A​(p.Thr527Lys) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,608 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. T527M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SMCHD1 NM_015295.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.33

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 Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr18-2700851-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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMCHD1	NM_015295.3	c.1580C>A	p.Thr527Lys	missense_variant	Exon 12 of 48	ENST00000320876.11	NP_056110.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMCHD1	ENST00000320876.11	c.1580C>A	p.Thr527Lys	missense_variant	Exon 12 of 48	5	NM_015295.3	ENSP00000326603.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460608 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726600

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
CADD	Uncertain	24
DANN	Benign	0.90
DEOGEN2	Benign	0.27	T
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.83	T
M_CAP	Uncertain	0.17	D
MetaRNN	Uncertain	0.52	D
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.1	M
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-2.9	D
REVEL	Benign	0.19
Sift	Benign	0.20	T
Sift4G	Pathogenic	0.0	D
Polyphen		0.96	D
Vest4		0.57
MutPred		0.28		Gain of ubiquitination at T527 (P = 0.03);
MVP		0.70
MPC		1.8
ClinPred		0.83	D
GERP RS		5.5
Varity_R		0.29
gMVP		0.91

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: chr18-2700849;