rs1554493872

Variant names:

• chr7-155803643-TCAC-T
• rs1554493872
• NM_000193.4:c.643_645delGTG

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PM4_Supporting

The NM_000193.4(SHH):​c.643_645delGTG​(p.Val215del) variant causes a conservative inframe deletion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SHH NM_000193.4 conservative_inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.55
• Publications: 0 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

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000193.4
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000193.4. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SHH	NM_000193.4	c.643_645delGTG	p.Val215del	conservative_inframe_deletion	Exon 3 of 3	ENST00000297261.7	NP_000184.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SHH	ENST00000297261.7	c.643_645delGTG	p.Val215del	conservative_inframe_deletion	Exon 3 of 3	1	NM_000193.4	ENSP00000297261.2
SHH	ENST00000430104.5	c.301+2650_301+2652delGTG		intron_variant	Intron 3 of 3	1		ENSP00000396621.1
SHH	ENST00000435425.1	n.301+2650_301+2652delGTG		intron_variant	Intron 3 of 4	1		ENSP00000413871.1
SHH	ENST00000441114.5	n.301+2650_301+2652delGTG		intron_variant	Intron 3 of 4	1		ENSP00000410546.1

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Holoprosencephaly 3 Uncertain:1

Jan 31, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this is a novel in-frame deletion with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the deleted amino acid is currently unknown. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with an SHH-related disease. However, family studies performed at Invitae have indicated that an individual with holoprosencephaly inherited this variant from a reportedly unaffected parent. This sequence change deletes 3 nucleotides from exon 3 of the SHH mRNA (c.643_645delGTG). This leads to the deletion of 1 amino acid residue in the SHH protein (p.Val215del) but otherwise preserves the integrity of the reading frame. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.5

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

Other links and lift over

dbSNP: rs1554493872; hg19: chr7-155596337;