chr7-155811825-G-A

Variant names:

• chr7-155811825-G-A
• rs104894044
• NM_000193.4:c.298C>T

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PVS1 PM2 PP3 PP5_Moderate

The NM_000193.4(SHH):​c.298C>T​(p.Gln100*) variant causes a stop gained, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SHH NM_000193.4 stop_gained, splice_region
• Scores: Splicing: ADA: 0.9974
• Clinical Significance: Pathogenic criteria provided, single submitter P:3
• Conservation: PhyloP100: 6.34
• Publications: 3 publications found

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]

SHH Gene-Disease associations (from GenCC):

• holoprosencephaly 3

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• microphthalmia, isolated, with coloboma 5

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, PanelApp Australia
• polydactyly of a triphalangeal thumb

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
• solitary median maxillary central incisor syndrome

  Inheritance: AD Classification: DEFINITIVE, MODERATE Submitted by: G2P, Ambry Genetics
• skeletal system disorder

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• autosomal dominant preaxial polydactyly-upperback hypertrichosis syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hypoplastic tibiae-postaxial polydactyly syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• microphthalmia, isolated, with coloboma

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• syndactyly type 4

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• triphalangeal thumb-polysyndactyly syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• holoprosencephaly

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000296779 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 13 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 7-155811825-G-A is Pathogenic according to our data. Variant chr7-155811825-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 8878.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SHH	NM_000193.4	c.298C>T	p.Gln100*	stop_gained, splice_region_variant	Exon 1 of 3	ENST00000297261.7	NP_000184.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SHH	ENST00000297261.7	c.298C>T	p.Gln100*	stop_gained, splice_region_variant	Exon 1 of 3	1	NM_000193.4	ENSP00000297261.2
ENSG00000296779	ENST00000741965.1	n.98G>A		non_coding_transcript_exon_variant	Exon 1 of 2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, single submitter

Submissions by phenotype

Holoprosencephaly 3 Pathogenic:3

Nov 01, 1996

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Aug 29, 2013

GeneReviews

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

- -

Feb 27, 2025

Laboratory of Molecular Genetics, CHU Rennes

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NM_000193.4:c.298C>T, is a nonsense variant in SHH which is predicted to result in a premature stop codon at position 100, and likely results in an absent or disrupted protein product (PVS1). This variant This variant occurred de novo (PS2). This variant is not present in gnomAD (PM2). In summary, this variant meets criteria to be classified as pathogenic for holoprosencephaly based on the ACMG criteria applied. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	51
DANN	Uncertain	1.0
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Uncertain	0.94	D
PhyloP100		6.3
Vest4		0.89
GERP RS		4.4
Mutation Taster		=2/198	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.85
SpliceAI score (max)		0.020		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: rs104894044; hg19: chr7-155604519;