chr12-120994264-C-T

Variant names:

• chr12-120994264-C-T
• rs1555212014
• NM_000545.8:c.814C>T

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PP1_Strong PS4 PS3_Supporting PP4_Moderate PM2_Supporting PP3 PM5 PM1

This summary comes from the ClinGen Evidence Repository: The c.814C>T variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of arginine to cystine at codon 272 (p.(Arg272Cys) of transcript, e.g. 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 absent from gnomAD v2.1.1 (PM2_Supporting). Additionally, this variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.941, which is greater than the MDEP VCEP threshold of 0.70 (PP3). This variant was identified in at least 17 unrelated individuals with non- autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4; PMIDs: 18003757, 28701371, 25414397, 11719843, 10447526; internal lab contributors). The variant segregated with diabetes, with at least fifteen informative meioses in at least sixteen families with MODY (PP1_Strong; internal lab contributors). Another missense variant, c. 815G>A, p.Arg272His, has been interpreted as pathogenic by the ClinGen MDEP and p.Arg272Cys has a greater Grantham distance (PM5). Functional studies demonstrated the p.Arg272Cys protein has DNA binding below 40% of wild type and transactivation below 40% of wildtype, indicating that this variant impacts protein function (PS3_Supporting; PMID:10333057). Lastly, this variant was identified in at least five individuals with a clinical history highly specific for HNF1A-MODY (MODY probability calculator result >50%, negative genetic testing for HNF4A, and response to low dose sulfonylurea) (PP4_Moderate; internal lab contributors). In summary, c.814C>T, meets the criteria to be classified as pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 1.1, approved 9/30/2021): PM1, PM2_Supporting, PP3, PS4, PP1_Strong, PM5, PS3_Supporting, PP4_Moderate. LINK:https://erepo.genome.network/evrepo/ui/classification/CA386966363/MONDO:0015967/017

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF1A NM_001306179.2 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:10
• Conservation: PhyloP100: 1.79
• Publications: 1 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: Pathogenic. The variant received 17 ACMG points.

• PS3: For more information check the summary or visit ClinGen Evidence Repository.
• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• 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.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HNF1A	NM_000545.8	MANE Select	c.814C>T	p.Arg272Cys	missense	Exon 4 of 10	NP_000536.6
	HNF1A	NM_001306179.2		c.814C>T	p.Arg272Cys	missense	Exon 4 of 10	NP_001293108.2
	HNF1A	NM_001406915.1		c.814C>T	p.Arg272Cys	missense	Exon 4 of 9	NP_001393844.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HNF1A	ENST00000257555.11	TSL:1 MANE Select	c.814C>T	p.Arg272Cys	missense	Exon 4 of 10	ENSP00000257555.5
	HNF1A	ENST00000544413.2	TSL:1	c.814C>T	p.Arg272Cys	missense	Exon 4 of 10	ENSP00000438804.1
	HNF1A	ENST00000538646.5	TSL:1	n.627C>T		non_coding_transcript_exon	Exon 3 of 6	ENSP00000443964.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
5	-	-	not provided (5)
2	-	-	Maturity onset diabetes mellitus in young (2)
1	-	-	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 (1)
1	-	-	Maturity-onset diabetes of the young type 3 (1)
1	-	-	Monogenic diabetes (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.93	D
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
PhyloP100		1.8
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-6.3	D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.81		Gain of methylation at K273 (P = 0.0249)
MVP		1.0
MPC		2.5
ClinPred		0.99	D
GERP RS		3.9
gMVP		1.0
Mutation Taster		=0/100	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: rs1555212014; hg19: chr12-121432067; COSMIC: COSV57462785;