rs1554493882

Positions:

• chr7-155803660-C-A
• chr7-155803660-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000193.4(SHH):​c.629G>T​(p.Gly210Val) 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. 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. G210D) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SHH NM_000193.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.47

Genes affected

SHH (HGNC:10848): (sonic hedgehog signaling molecule) This gene encodes a protein that is instrumental in patterning the early embryo. It has been implicated as the key inductive signal in patterning of the ventral neural tube, the anterior-posterior limb axis, and the ventral somites. Of three human proteins showing sequence and functional similarity to the sonic hedgehog protein of Drosophila, this protein is the most similar. The protein is made as a precursor that is autocatalytically cleaved; the N-terminal portion is soluble and contains the signalling activity while the C-terminal portion is involved in precursor processing. More importantly, the C-terminal product covalently attaches a cholesterol moiety to the N-terminal product, restricting the N-terminal product to the cell surface and preventing it from freely diffusing throughout the developing embryo. Defects in this protein or in its signalling pathway are a cause of holoprosencephaly (HPE), a disorder in which the developing forebrain fails to correctly separate into right and left hemispheres. HPE is manifested by facial deformities. It is also thought that mutations in this gene or in its signalling pathway may be responsible for VACTERL syndrome, which is characterized by vertebral defects, anal atresia, tracheoesophageal fistula with esophageal atresia, radial and renal dysplasia, cardiac anomalies, and limb abnormalities. Additionally, mutations in a long range enhancer located approximately 1 megabase upstream of this gene disrupt limb patterning and can result in preaxial polydactyly. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.982

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SHH	NM_000193.4	c.629G>T	p.Gly210Val	missense_variant	3/3	ENST00000297261.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SHH	ENST00000297261.7	c.629G>T	p.Gly210Val	missense_variant	3/3	1	NM_000193.4	P1
SHH	ENST00000430104.5	c.301+2636G>T		intron_variant		1
SHH	ENST00000435425.1	c.301+2636G>T		intron_variant, NMD_transcript_variant		1
SHH	ENST00000441114.5	c.301+2636G>T		intron_variant, NMD_transcript_variant		1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Holoprosencephaly 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 25, 2021

This variant has not been reported in the literature in individuals with SHH-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with valine at codon 210 of the SHH protein (p.Gly210Val). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and valine. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.75
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.99	D
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.1	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-7.0	D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.53
MutPred		0.90		Loss of disorder (P = 0.0303);
MVP		0.91
ClinPred		1.0	D
GERP RS		3.5
Varity_R		0.95
gMVP		0.99

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: chr7-155596354;