12-120988898-G-T

Variant names:

• chr12-120988898-G-T
• rs753998395
• NM_000545.8:c.392G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM5_Strong PM2_Supporting PP3 PM1

This summary comes from the ClinGen Evidence Repository: The c.392G>T variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of arginine to leucine at codon 131 (p.(R131L)) of NM_000545.8. This variant resides in an amino acid within the HNF1α DNA binding domain that directly binds DNA, which is defined as critical for the protein’s function by the ClinGen MDEP (PM1), and is predicted to be deleterious by computational evidence, with a REVEL score of 0.994, which is greater than the MDEP threshold of 0.70 (PP3). Two other missense variants, c.392G>A (p.Arg131Gln) and c.391C>T (p.Arg131Trp), have been interpreted as pathogenic by the ClinGen MDEP (PM5_Strong). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). This variant was identified in an individual with non-autoimmune and non-absolute/near-absolute insulin-deficient diabetes; however, PS4 cannot be applied because this number is below the ClinGen MDEP threshold (ClinVar ID: 447488). Taken together, this evidence supports the classification of this variant as likely pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP VCEP (specification version 1.0, approved): PM5_Strong, PM1, PP3, PM2_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA386959454/MONDO:0015967/017

• Frequency: Genomes: not found (cov: 33)
• Consequence: HNF1A NM_000545.8 missense
• Clinical Significance: Likely pathogenic reviewed by expert panel P:2
• Conservation: PhyloP100: 9.51
• Publications: 28 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 Gene-Disease associations (from GenCC):

• monogenic diabetes

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• type 1 diabetes mellitus 20

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, Genomics England PanelApp
• diabetes mellitus, noninsulin-dependent

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• maturity-onset diabetes of the young type 3

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• hyperinsulinism due to HNF1A deficiency

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• maturity-onset diabetes of the young

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• nonpapillary renal cell carcinoma

  Inheritance: Unknown Classification: NO_KNOWN Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM5: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000545.8. 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.392G>T	p.Arg131Leu	missense	Exon 2 of 10	NP_000536.6
	HNF1A	NM_001306179.2		c.392G>T	p.Arg131Leu	missense	Exon 2 of 10	NP_001293108.2
	HNF1A	NM_001406915.1		c.392G>T	p.Arg131Leu	missense	Exon 2 of 9	NP_001393844.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HNF1A	ENST00000257555.11	TSL:1 MANE Select	c.392G>T	p.Arg131Leu	missense	Exon 2 of 10	ENSP00000257555.5
	HNF1A	ENST00000544413.2	TSL:1	c.392G>T	p.Arg131Leu	missense	Exon 2 of 10	ENSP00000438804.1
	HNF1A	ENST00000538646.5	TSL:1	n.392G>T		non_coding_transcript_exon	Exon 2 of 6	ENSP00000443964.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: reviewed by expert panel

Submissions by phenotype

Monogenic diabetes Pathogenic:1

Sep 02, 2025

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.392G>T variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of arginine to leucine at codon 131 (p.(Arg131Leu)) of NM_000545.8. This variant resides in an amino acid within the HNF1α DNA binding domain that directly binds DNA, which is defined as critical for the protein’s function by the ClinGen MDEP (PM1), and is predicted to be deleterious by computational evidence, with a REVEL score of 0.994, which is greater than the MDEP threshold of 0.70 (PP3). Two other missense variants, c.392G>A (p.Arg131Gln) and c.391C>T (p.Arg131Trp), have been interpreted as pathogenic by the ClinGen MDEP (PM5_Strong). This variant is absent from gnomAD v4.1.0 (PM2_Supporting). This variant was identified in an individual with non-autoimmune and non-absolute/near-absolute insulin-deficient diabetes; however, PS4 cannot be applied because this number is below the ClinGen MDEP threshold (ClinVar ID: 447488). Taken together, this evidence supports the classification of this variant as likely pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP VCEP (specification version 3.0.0, approved 6/30/2025): PM5_Strong, PM1, PP3, PM2_Supporting.

not provided Pathogenic:1

Feb 08, 2023

Athena Diagnostics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has been identified in at least one individual with clinical features associated with this gene. This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). At least one other missense variant at this codon is considered to be pathogenic or likely pathogenic, suggesting this variant may also cause disease. The variant is located in a region that is considered important for protein function and/or structure. Computational tools predict that this variant is damaging.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
PhyloP100		9.5
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-6.5	D
REVEL	Pathogenic	0.99
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.96		Loss of MoRF binding (P = 0.0623)
MVP		0.99
MPC		1.3
ClinPred		1.0	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
gMVP		0.95
Mutation Taster		=5/95	disease causing

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: rs753998395; hg19: chr12-121426701; COSMIC: COSV57460960;