rs794727618

chr20-10658561-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_000214.3(JAG1):c.601C>T(p.Arg201Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: JAG1 NM_000214.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:4
• Conservation: PhyloP100: 6.71

Genes affected

JAG1 (HGNC:6188): (jagged canonical Notch ligand 1) The jagged 1 protein encoded by JAG1 is the human homolog of the Drosophilia jagged protein. Human jagged 1 is the ligand for the receptor notch 1, the latter is involved in signaling processes. Mutations that alter the jagged 1 protein cause Alagille syndrome. Jagged 1 signalling through notch 1 has also been shown to play a role in hematopoiesis. [provided by RefSeq, Nov 2019]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a domain DSL (size 44) in uniprot entity JAG1_HUMAN there are 18 pathogenic changes around while only 2 benign (90%) in NM_000214.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, JAG1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.911

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
JAG1	NM_000214.3	c.601C>T	p.Arg201Cys	missense_variant	4/26	ENST00000254958.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
JAG1	ENST00000254958.10	c.601C>T	p.Arg201Cys	missense_variant	4/26	1	NM_000214.3	P1
JAG1	ENST00000423891.6	n.467C>T		non_coding_transcript_exon_variant	2/25	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461886 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 727246

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 05, 2017	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Apr 01, 2020	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Mar 24, 2020

Variant summary: JAG1 c.601C>T (p.Arg201Cys) results in a non-conservative amino acid change located in the disulphide-rich Delta/Serrate/Lag-2 (DSL) protein domain (IPR001774 and Cordle_2008) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251452 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.601C>T has been reported in the literature in at least one individual with an atypical presentation of Alagille syndrome (Wu_2018). These data do not allow clear conclusions about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. However, a study investigated a different missense (Arg201Ala) affecting the same residue, and found a partial loss of function, for both in vitro Notch-binding and in vivo signaling in Drosophila (Cordle_2008). These data might support a functional role for the Arg 201 residue. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and both of them classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

JAG1-related condition Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Nov 02, 2022

The JAG1 c.601C>T variant is predicted to result in the amino acid substitution p.Arg201Cys. This variant was reported in an individual with atypical clinical and histopathologic presentation of Alagille syndrome (Wu et al. 2018. PubMed ID: 29187043). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Of note, functional studies in a fruit fly model showed that a similar variant p.Arg201Ala could impact normal protein function (Cordle et al. 2008. PubMed ID: 18660822). Although we suspect that the c.601C>T (p.Arg201Cys) variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Alagille syndrome due to a JAG1 point mutation Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 01, 2023

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. 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 JAG1 protein function. ClinVar contains an entry for this variant (Variation ID: 197123). This missense change has been observed in individual(s) with Alagille syndrome (PMID: 29187043). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 201 of the JAG1 protein (p.Arg201Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
Cadd	Pathogenic	28
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.39	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.3	M
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-7.0	D
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.66
MutPred		0.73		Gain of ubiquitination at K198 (P = 0.0961);
MVP		0.97
MPC		2.7
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.98
gMVP		0.96

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

LitVar

Other links and lift over

dbSNP: rs794727618; hg19: chr20-10639209;