12-120979096-T-G

Variant names:

• chr12-120979096-T-G
• rs1555210478
• NM_000545.8:c.326+2T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PVS1 PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The c.326+2T>G variant in the HNF1 homeobox A gene, HNF1A, is predicted to remove a canonical splice donor site in intron 1 of NM_000545.8. This variant is predicted to cause skipping of biologically-relevant exon 2 of 10, resulting in a frameshift, leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1; PMID:23348805). This variant is also absent from gnomAD v2.1.1 (PM2_Supporting). In summary, c.326+2T>G meets the criteria to be classified as likely pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 1.1, approved 9/30/2021): PVS1, PM2_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA386955008/MONDO:0015967/017

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF1A NM_001306179.2 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3
• Conservation: PhyloP100: 7.23
• Publications: 0 publications found

Genes affected

HNF1A (HGNC:11621): (HNF1 homeobox A) The protein encoded by this gene is a transcription factor required for the expression of several liver-specific genes. The encoded protein functions as a homodimer and binds to the inverted palindrome 5'-GTTAATNATTAAC-3'. Defects in this gene are a cause of maturity onset diabetes of the young type 3 (MODY3) and also can result in the appearance of hepatic adenomas. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Apr 2015]

HNF1A-AS1 (HGNC:26785): (HNF1A antisense RNA 1)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001306179.2. 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
	HNF1A	NM_000545.8	MANE Select	c.326+2T>G		splice_donor intron	N/A	NP_000536.6
	HNF1A	NM_001306179.2		c.326+2T>G		splice_donor intron	N/A	NP_001293108.2
	HNF1A	NM_001406915.1		c.326+2T>G		splice_donor intron	N/A	NP_001393844.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HNF1A	ENST00000257555.11	TSL:1 MANE Select	c.326+2T>G		splice_donor intron	N/A	ENSP00000257555.5
	HNF1A	ENST00000544413.2	TSL:1	c.326+2T>G		splice_donor intron	N/A	ENSP00000438804.1
	HNF1A	ENST00000535955.5	TSL:1	n.42+404T>G		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Likely pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
1	-	-	Maturity onset diabetes mellitus in young (1)
1	-	-	Monogenic diabetes (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	29
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.2
GERP RS		4.5
PromoterAI		-0.11	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.3
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.98		Position offset: -2

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

Other links and lift over

dbSNP: rs1555210478; hg19: chr12-121416899;