rs267606873

Variant names:

• chr2-219057627-C-T
• rs267606873
• NM_002181.4:c.383G>A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_002181.4(IHH):​c.383G>A​(p.Arg128Gln) variant causes a missense change involving the alteration of a conserved nucleotide. 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R128L) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: IHH NM_002181.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.88

Genes affected

IHH (HGNC:5956): (Indian hedgehog signaling molecule) This gene encodes a member of the hedgehog family of proteins. The encoded preproprotein is proteolytically processed to generate multiple protein products, including an N-terminal fragment that is involved in signaling. Hedgehog family proteins are essential secreted signaling molecules that regulate a variety of developmental processes including growth, patterning and morphogenesis. The protein encoded by this gene specifically plays a role in bone growth and differentiation. Mutations in this gene are the cause of brachydactyly type A1, which is characterized by shortening or malformation of the fingers and toes. Mutations in this gene are also the cause of acrocapitofemoral dysplasia. [provided by RefSeq, Nov 2015]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a chain Indian hedgehog protein N-product (size 174) in uniprot entity IHH_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_002181.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-219057627-C-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989
• PP5: Variant 2-219057627-C-T is Pathogenic according to our data. Variant chr2-219057627-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 8875.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IHH	NM_002181.4	c.383G>A	p.Arg128Gln	missense_variant	Exon 2 of 3	ENST00000295731.7	NP_002172.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IHH	ENST00000295731.7	c.383G>A	p.Arg128Gln	missense_variant	Exon 2 of 3	1	NM_002181.4	ENSP00000295731.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Brachydactyly type A1 Pathogenic:1

Sep 01, 2009

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided Pathogenic:1

Dec 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense change has been observed in individuals with autosomal dominant brachydactyly (PMID: 19277064; Invitae). It has also been observed to segregate with disease in related individuals. This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 128 of the IHH protein (p.Arg128Gln). This variant is not present in population databases (gnomAD no frequency). ClinVar contains an entry for this variant (Variation ID: 8875). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt IHH protein function. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.99	D
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.37	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.6	M
PrimateAI	Pathogenic	0.87	D
PROVEAN	Uncertain	-3.6	D
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0060	D
Sift4G	Uncertain	0.0080	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.93		Loss of MoRF binding (P = 0.0417);
MVP		0.98
MPC		2.6
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.96
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs267606873; hg19: chr2-219922349;