chr12-120997588-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received -2 ACMG points: 2P and 4B. PP3PP4BS2

This summary comes from the ClinGen Evidence Repository: The c.1424C>T variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of proline to leucine at codon 475 (p.(Pro475Leu)) of NM_000545.8. This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.751, which is greater than the MDEP VCEP threshold of 0.70 (PP3). Additionally, this variant was identified in an individual with a clinical history highly specific for HNF1A-MODY (MODY probability calculator result >50%, negative genetic testing for HNF4A) (PP4; internal lab contributors). This variant was identified in at least 10 unrelated individuals with non- autoimmune and non-absolute/near-absolute insulin-deficient diabetes; however, PS4 cannot be applied because the variant MAF in gnomAD is above the ClinGen MDEP PM2_Supporting cutoff (PMIDs: 18811724, 23674172, internal lab contributors). This variant was identified in a normoglycemic individual >70 years old, and the expected penetrance for HNF1A-MODY is 95% by age 70 (BS2: internal lab contributors). The frequency of the c.1424C>T variant in gnomAD v2.1.1 falls between the ClinGen MDEP-established cutoffs for PM2_Supporting and BS1; thus, neither criterion will be applied. In summary, c.1424C>T meets the criteria to be classified as a variant of uncertain significance for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 2.1.0, approved 8/11/2023): PP3, PP4, BS2. LINK:https://erepo.genome.network/evrepo/ui/classification/CA214266/MONDO:0015967/017

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000050 ( 0 hom. )

Consequence

HNF1A
NM_000545.8 missense

Scores

Clinical Significance

Uncertain significance reviewed by expert panel U:5B:2

Conservation

PhyloP100: 3.83

Publications

11 publications found

Variant links:

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)

HNF1A links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received -2 ACMG points.

PP3

For more information check the summary or visit ClinGen Evidence Repository.

PP4

For more information check the summary or visit ClinGen Evidence Repository.

BS2

For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HNF1A	NM_000545.8 link	c.1424C>T	p.Pro475Leu	missense_variant	Exon 7 of 10	ENST00000257555.11	NP_000536.6	P20823E0YMI7
HNF1A	NM_001306179.2 link	c.1424C>T	p.Pro475Leu	missense_variant	Exon 7 of 10		NP_001293108.2	P20823E0YMI7
HNF1A	XM_024449168.2 link	c.1424C>T	p.Pro475Leu	missense_variant	Exon 7 of 9		XP_024304936.1
HNF1A	NM_001406915.1 link	c.1309+846C>T		intron_variant	Intron 6 of 8		NP_001393844.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HNF1A	ENST00000257555.11 link	c.1424C>T	p.Pro475Leu	missense_variant	Exon 7 of 10	1	NM_000545.8	ENSP00000257555.5		A0A0A0MQU7

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152222

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000864

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.0000520

AC:

AN:

249896

AF XY:

0.0000591

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000995

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000266

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000499

AC:

AN:

1461498

Hom.:

Cov.:

AF XY:

0.0000440

AC XY:

AN XY:

727078

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44700

Ashkenazi Jewish (ASJ)

AF:

0.00180

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39690

South Asian (SAS)

AF:

0.00

AC:

AN:

86220

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53160

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000171

AC:

AN:

1111964

Other (OTH)

AF:

0.000116

AC:

AN:

60388

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.442

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74370

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41454

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.000864

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10630

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68038

Other (OTH)

AF:

0.000478

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.550

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000163

Hom.:

Bravo

AF:

0.0000340

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5Benign:2

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Monogenic diabetes

Uncertain:2

Jan 22, 2020

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:curation

The p.Pro475Leu variant in HNF1A has been reported in at least 2 individuals (including 1 Thai individual) with Monogenic Diabetes (PMID: 18811724, 23348805), and has been identified in 0.09954% (10/10046) of Ashkenazi Jewish chromosomes and 0.002659% (3/112840) European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs193922580). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a carrier frequency. Please note that for diseases with clinical variability, or reduced penetrance, pathogenic variants may be present at a low frequency in the general population. This variant has also been reported likely pathogenic in ClinVar and as a VUS in the literature (Variation ID: 36801; PMID: 27080136). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of the p.Pro475Leu variant is uncertain. ACMG/AMP Criteria applied: PM2_Supporting, PP3, PS4_Supporting (Richards 2015). -

Aug 01, 2024

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Significance:Uncertain significance

Review Status:reviewed by expert panel

Collection Method:curation

The c.1424C>T variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of proline to leucine at codon 475 (p.(Pro475Leu)) of NM_000545.8. This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.751, which is greater than the MDEP VCEP threshold of 0.70 (PP3). Additionally, this variant was identified in an individual with a clinical history highly specific for HNF1A-MODY (MODY probability calculator result >50%, negative genetic testing for HNF4A) (PP4; internal lab contributors). This variant was identified in at least 10 unrelated individuals with non- autoimmune and non-absolute/near-absolute insulin-deficient diabetes; however, PS4 cannot be applied because the variant MAF in gnomAD is above the ClinGen MDEP PM2_Supporting cutoff (PMIDs: 18811724, 23674172, internal lab contributors). This variant was identified in a normoglycemic individual >70 years old, and the expected penetrance for HNF1A-MODY is 95% by age 70 (BS2: internal lab contributors). The frequency of the c.1424C>T variant in gnomAD v2.1.1 falls between the ClinGen MDEP-established cutoffs for PM2_Supporting and BS1; thus, neither criterion will be applied. In summary, c.1424C>T meets the criteria to be classified as a variant of uncertain significance for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 2.1.0, approved 8/11/2023): PP3, PP4, BS2. -

not provided

Uncertain:1Benign:1

Sep 11, 2018

Athena Diagnostics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Diabetes mellitus type 1;C0011860:Type 2 diabetes mellitus;C1838100:Maturity-onset diabetes of the young type 3;C1840646:Hepatic adenomas, familial;C2675866:Type 1 diabetes mellitus 20;CN074294:Nonpapillary renal cell carcinoma

Uncertain:1

Apr 18, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Maturity onset diabetes mellitus in young

Uncertain:1

Jan 20, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.P475L variant (also known as c.1424C>T), located in coding exon 7 of the HNF1A gene, results from a C to T substitution at nucleotide position 1424. The proline at codon 475 is replaced by leucine, an amino acid with similar properties. This alteration has been reported in a Thai subject with type 2 diabetes (Plengvidhya N et al. Clin Endocrinol (Oxf), 2009 Jun;70:847-53). This variant has been noted to have reduced transactivation activity and affected cell cycle and growth (Sujjitjoon J et al. Biochem Biophys Res Commun, 2020 Aug;529:826-833). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not specified

Benign:1

May 26, 2025

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

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: HNF1A c.1424C>T (p.Pro475Leu) results in a non-conservative amino acid change located in the Hepatocyte nuclear factor 1, beta isoform, C-terminal domain (IPR006897) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 4.8e-05 in 1613850 control chromosomes. The observed variant frequency is approximately 2 fold of the estimated maximal expected allele frequency for a pathogenic variant in HNF1A causing Maturity Onset Diabetes Of The Young 3 phenotype (2.5e-05), suggesting that the variant may be benign. c.1424C>T has been reported in the literature in several individuals affected with diabetes (e.g., Plengvidhya_2009, Billings_2022), however without strong evidence for causality (e.g., lack of co-segregation data) in all cases. The variant was also identified in several unaffected control individuals (e.g., Billings_2022). These reports therefore do not provide unequivocal conclusions about association of the variant with Maturity Onset Diabetes Of The Young 3. At least one publication reports experimental evidence evaluating an impact on protein function, finding that the variant results in moderate defects in BCL2L1 transactivation (approx. 28% reduction relative to wildtype) as well as defects in regulation of cell cycle transitions (e.g., Sujjitjoon_2020). The following publications have been ascertained in the context of this evaluation (PMID: 36208030, 18811724, 32684311, 39379762). ClinVar contains an entry for this variant (Variation ID: 36801). Based on the evidence outlined above, the variant was classified as likely benign. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Pathogenic

0.28

BayesDel_noAF

Pathogenic

0.17

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.82

.;D;D;.;T;.

Eigen

Uncertain

0.53

Eigen_PC

Uncertain

0.44

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.92

D;D;D;D;D;D

M_CAP

Uncertain

0.18

MetaRNN

Uncertain

0.69

D;D;D;D;D;D

MetaSVM

Pathogenic

1.1

PhyloP100

3.8

PrimateAI

Uncertain

0.53

PROVEAN

Uncertain

-4.2

D;.;.;.;D;D

REVEL

Pathogenic

0.75

Sift

Uncertain

0.0010

D;.;.;.;D;D

Sift4G

Uncertain

0.0090

D;D;D;D;D;D

Polyphen

1.0

.;.;.;.;.;D

Vest4

0.83

MVP

0.92

MPC

0.40

ClinPred

0.83

GERP RS

4.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

gMVP

0.90

Mutation Taster

=41/59

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over