12-120988841-C-T

Position:

• chr12-120988841-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PP3 PM2_Supporting PM1 PS3 PS4_Moderate PP1_Strong PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The c.335C>T variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of proline to leucine at codon 112 (p.(Pro112Leu)) of NM_000545.8. This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.966, which is greater than the MDEP VCEP threshold of 0.70 (PP3) and is absent from gnomAD v2.1.1 (PM2_Supporting). Additionally, this variant is located within a conserved region of the DNA binding domain (codons 107-174 and 201-280) of HNF1A, which is defined as critical for the protein’s function by the ClinGen MDEP (PM1_Supporting). This variant was identified in six unrelated individuals with non- autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4_Moderate; internal lab contributors). This variant was identified in two 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 sulfonylureas) (PP4_Moderate; internal lab contributors). A luciferase assay meeting the ClinGen MDEP quality control specifications demonstrated that the p.Pro112Leu protein has transactivation activity below 40% of wildtype, indicating that this variant impacts protein function (PS3_Moderate, PMID:32910913). Lastly, this variant segregated with diabetes, with 11 informative meioses in six families with MODY (PP1_Strong; internal lab contributors). In summary, c.335C>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 9/30/21): PP3, PM1_Supporting, PM2_Supporting, PP4_Moderate, PS4_Moderate,PS3_Moderate, PP1_Strong. LINK:https://erepo.genome.network/evrepo/ui/classification/CA124475/MONDO:0015967/017

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: HNF1A NM_000545.8 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:6
• Conservation: PhyloP100: 7.50

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]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HNF1A	NM_000545.8	c.335C>T	p.Pro112Leu	missense_variant	2/10	ENST00000257555.11
HNF1A	NM_001306179.2	c.335C>T	p.Pro112Leu	missense_variant	2/10
HNF1A	NM_001406915.1	c.335C>T	p.Pro112Leu	missense_variant	2/9
HNF1A	XM_024449168.2	c.335C>T	p.Pro112Leu	missense_variant	2/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HNF1A	ENST00000257555.11	c.335C>T	p.Pro112Leu	missense_variant	2/10	1	NM_000545.8	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251202 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135780

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461866 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727236

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: reviewed by expert panel

Submissions by phenotype

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jan 04, 2022	Published functional studies demonstrate impaired DNA binding and significantly reduced transcriptional activity (Bjrkhaug et al., 2000; Xu et al., 2002; Najmi et al., 2016); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 17989309, 12107757, 12574234, 15657605, 27899486, 26431509, 24915262, 18003757, 12453420, 11162430, 21518407, 32910913) -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 13, 2023	This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 112 of the HNF1A protein (p.Pro112Leu). This variant is present in population databases (rs137853243, gnomAD 0.0009%). This missense change has been observed in individuals with clinical features of maturity-onset diabetes of the young (MODY) (PMID: 11162430, 21518407). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 14942). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt HNF1A protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change affects HNF1A function (PMID: 11162430, 27899486, 35472491). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Dec 07, 2016	- -

Maturity-onset diabetes of the young type 3 Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Feb 01, 2003	- -
Pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	May 06, 2021	Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with type III maturity-onset diabetes of the young (MODY type III; MIM#600496). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from proline to leucine. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v2) <0.001 for a dominant condition (1 heterozygote, 0 homozygotes). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated DNA-binding domain (PMID: 32910913). (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. It has been reported in multiple families with MODY (ClinVar, PMIDs: 11162430, 12107757, 21518407, 32238361). (SP) 1001 - This variant has strong functional evidence supporting abnormal protein function. Studies performed by multiple laboratories have shown that it reduced protein expression, transcriptional activity, DNA binding and also resulted in impaired subcellular localisation (PMID: 32910913). (SP) 1205 - This variant has been shown to be maternally inherited. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Monogenic diabetes Pathogenic:1

Pathogenic, reviewed by expert panel

curation

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Apr 08, 2022

The c.335C>T variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of proline to leucine at codon 112 (p.(Pro112Leu)) of NM_000545.8. This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.966, which is greater than the MDEP VCEP threshold of 0.70 (PP3) and is absent from gnomAD v2.1.1 (PM2_Supporting). Additionally, this variant is located within a conserved region of the DNA binding domain (codons 107-174 and 201-280) of HNF1A, which is defined as critical for the protein’s function by the ClinGen MDEP (PM1_Supporting). This variant was identified in six unrelated individuals with non- autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4_Moderate; internal lab contributors). This variant was identified in two 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 sulfonylureas) (PP4_Moderate; internal lab contributors). A luciferase assay meeting the ClinGen MDEP quality control specifications demonstrated that the p.Pro112Leu protein has transactivation activity below 40% of wildtype, indicating that this variant impacts protein function (PS3_Moderate, PMID: 32910913). Lastly, this variant segregated with diabetes, with 11 informative meioses in six families with MODY (PP1_Strong; internal lab contributors). In summary, c.335C>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 9/30/21): PP3, PM1_Supporting, PM2_Supporting, PP4_Moderate, PS4_Moderate,PS3_Moderate, PP1_Strong. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.91	.;D;D;D;D;.
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	A;A;A;A;A
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-7.6	D;.;.;.;D;D
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0010	D;.;.;.;D;D
Sift4G	Uncertain	0.0020	D;D;D;D;D;D
Polyphen		1.0	.;.;.;.;.;D
Vest4		0.94
MutPred		0.90		Gain of MoRF binding (P = 0.0468);Gain of MoRF binding (P = 0.0468);Gain of MoRF binding (P = 0.0468);Gain of MoRF binding (P = 0.0468);Gain of MoRF binding (P = 0.0468);Gain of MoRF binding (P = 0.0468);
MVP		0.98
MPC		2.1
ClinPred		1.0	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
gMVP		0.98

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

LitVar

Other links and lift over

dbSNP: rs137853243; hg19: chr12-121426644; COSMIC: COSV57465455;