12-121001192-A-G

Variant summary

Our verdict is Uncertain significance. The variant received -1 ACMG points: 0P and 1B. BP7

This summary comes from the ClinGen Evidence Repository: The c.1896A>G variant in the HNF1 homeobox A gene, HNF1A, is a synonymous (silent) variant at codon 632 (p.Ter632=) of NM_000545.8. This synonymous variant is not predicted by SpliceAI to impact splicing (BP7). The frequency of the c.1896A>G variant in gnomAD v2.1.1 is 0.0000265 in Non-Finnish Europeans, which falls between ClinGen MDEP-established cutoffs for PM2_Supporting and BS1; thus, neither criterion will be applied. In summary, c.1896A>G 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 1.1, approved 9/30/21): BP7. LINK:https://erepo.genome.network/evrepo/ui/classification/CA160007/MONDO:0015967/017

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

HNF1A
NM_000545.8 stop_retained

Scores

2

Clinical Significance

Uncertain significance reviewed by expert panel U:1B:1O:1

Conservation

PhyloP100: 2.80

Publications

2 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]
C12orf43 (HGNC:25719): (chromosome 12 open reading frame 43) Predicted to be involved in Spemann organizer formation and negative regulation of Wnt signaling pathway. Predicted to be located in nuclear envelope. [provided by Alliance of Genome Resources, Apr 2022]

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received -1 ACMG points.

BP7
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
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
HNF1A
NM_000545.8
MANE Select
c.1896A>Gp.Ter632Ter
stop_retained
Exon 10 of 10NP_000536.6
C12orf43
NM_022895.3
MANE Select
c.*2961T>C
3_prime_UTR
Exon 6 of 6NP_075046.1
HNF1A
NM_001306179.2
c.1917A>Gp.Ter639Ter
stop_retained
Exon 10 of 10NP_001293108.2

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
HNF1A
ENST00000257555.11
TSL:1 MANE Select
c.1896A>Gp.Ter632Ter
stop_retained
Exon 10 of 10ENSP00000257555.5
HNF1A
ENST00000544413.2
TSL:1
c.1917A>Gp.Ter639Ter
stop_retained
Exon 10 of 10ENSP00000438804.1
HNF1A
ENST00000540108.1
TSL:1
n.*1336A>G
non_coding_transcript_exon
Exon 9 of 9ENSP00000445445.1

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152056
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250476
AF XY:
0.00000738
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000265
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000410
AC:
6
AN:
1461638
Hom.:
0
Cov.:
33
AF XY:
0.00000413
AC XY:
3
AN XY:
727120
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53268
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1111936
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000132
AC:
2
AN:
152056
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74262
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41400
American (AMR)
AF:
0.0000655
AC:
1
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4806
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68008
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000288
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1Benign:1Other:1
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Monogenic diabetes Uncertain:1
Sep 02, 2025
ClinGen Monogenic Diabetes Variant Curation Expert Panel
Significance:Uncertain significance
Review Status:reviewed by expert panel
Collection Method:curation

The c.1896A>G variant in the HNF1 homeobox A gene, HNF1A, is a synonymous (silent) variant at codon 632 (p.Ter632=) of NM_000545.8. The computational splicing predictor SpliceAI gives a score of 0.01 for acceptor loss/gain, suggesting that the variant has no impact on splicing (BP4). However, BP7 was not applied for this synonymous variant because phyloP100way suggests conservation with a score >2.0 (2.801). This variant has a gnomAD v4.1.0 Grpmax filtering allele frequency of 0.00000247, which is below the ClinGen MDEP threshold of 0.000003 (PM2_Supporting). In summary, c.1896A>G 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 3.0.0, approved 6/30/2025): BP4, PM2_Supporting.

Maturity onset diabetes mellitus in young Benign:1
Sep 03, 2025
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

not specified Other:1
Sep 19, 2013
ITMI
Significance:not provided
Review Status:no classification provided
Collection Method:reference population

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.40
CADD
Benign
10
DANN
Benign
0.76
PhyloP100
2.8

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

Other links and lift over

dbSNP: rs587778395; hg19: chr12-121438995; API