chr20-10650275-T-TG

Variant names:

• chr20-10650275-T-TG
• rs35615084
• NM_000214.3:c.1205dupC

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000214.3(JAG1):​c.1205dupC​(p.Gln403ThrfsTer13) variant causes a frameshift 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: JAG1 NM_000214.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 8.11
• Publications: 1 publications found

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]

JAG1 Gene-Disease associations (from GenCC):

• Alagille syndrome due to a JAG1 point mutation

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• Charcot-Marie-Tooth disease, axonal, Type 2HH

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• tetralogy of fallot

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 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
• PP5: Variant 20-10650275-T-TG is Pathogenic according to our data. Variant chr20-10650275-T-TG is described in ClinVar as Pathogenic. ClinVar VariationId is 213558.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000214.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	JAG1	NM_000214.3	MANE Select	c.1205dupC	p.Gln403ThrfsTer13	frameshift	Exon 9 of 26	NP_000205.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	JAG1	ENST00000254958.10	TSL:1 MANE Select	c.1205dupC	p.Gln403ThrfsTer13	frameshift	Exon 9 of 26	ENSP00000254958.4
	JAG1	ENST00000423891.6	TSL:2	n.1071dupC		non_coding_transcript_exon	Exon 7 of 25
	JAG1	ENST00000617965.2	TSL:5	n.1794dupC		non_coding_transcript_exon	Exon 3 of 17

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Alagille syndrome due to a JAG1 point mutation Pathogenic:3

Nov 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Gln403Thrfs*13) in the JAG1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in JAG1 are known to be pathogenic (PMID: 11180599). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Alagille syndrome (PMID: 9585603). ClinVar contains an entry for this variant (Variation ID: 213558). For these reasons, this variant has been classified as Pathogenic.

Jun 01, 1998

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Jun 28, 2025

Immunogenetics and Transplant Biology Service, University Hospital "Città della Salute e della Scienza di Torino"

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Pathogenic:1

Jul 09, 2014

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1205dupC mutation in the JAG1 gene has been reported previously in association with Alagille syndrome using different nomenclature (Krantz, et al., 1998) . The duplication causes a frameshift starting with codon Glycine 403, changes this amino acid to a Threonine residue and creates a premature Stop codon at position 13 of the new reading frame, denoted p.Gln403ThrfsX13. This mutation is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay This variant was found in JAG1

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.1
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs35615084; hg19: chr20-10630923;