chr12-120994267-A-C

Position:

• chr12-120994267-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PP3 PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The c.817A>C variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of lysine to glutamine at codon 273 (p.(Lys273Gln) of NM_000545.8. This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.817, which is greater than the MDEP VCEP threshold of 0.70 (PP3). Additionally, 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). In summary, c.817A>C 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 9/30/2021): PM1, PM2_Supporting, PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA386966376/MONDO:0015967/017

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF1A NM_000545.8 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:1 U:2
• Conservation: PhyloP100: 8.86

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 Uncertain_significance. Variant got 4 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.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HNF1A	NM_000545.8	c.817A>C	p.Lys273Gln	missense_variant	4/10	ENST00000257555.11	NP_000536.6
HNF1A	NM_001306179.2	c.817A>C	p.Lys273Gln	missense_variant	4/10		NP_001293108.2
HNF1A	NM_001406915.1	c.817A>C	p.Lys273Gln	missense_variant	4/9		NP_001393844.1
HNF1A	XM_024449168.2	c.817A>C	p.Lys273Gln	missense_variant	4/9		XP_024304936.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HNF1A	ENST00000257555.11	c.817A>C	p.Lys273Gln	missense_variant	4/10	1	NM_000545.8	ENSP00000257555	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:2

Revision: reviewed by expert panel

Submissions by phenotype

Maturity onset diabetes mellitus in young Pathogenic:1

Likely risk allele, criteria provided, single submitter

research

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

-

Mutations in HNF1A gene can predispose to MODY3. It is associated with both micro and macrovascular complications of diabetes, especially cardiovascular complications. Associated with glucosuria. May respond well to sulfonylureas. However, more evidence is required to confer the association of this particular variant rs1555212016 with MODY3. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jun 12, 2017

- -

Monogenic diabetes Uncertain:1

Uncertain significance, reviewed by expert panel

curation

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Apr 14, 2022

The c.817A>C variant in the HNF1 homeobox A gene, HNF1A, causes an amino acid change of lysine to glutamine at codon 273 (p.(Lys273Gln) of NM_000545.8. This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.817, which is greater than the MDEP VCEP threshold of 0.70 (PP3). Additionally, 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). In summary, c.817A>C 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 9/30/2021): PM1, PM2_Supporting, PP3. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	31
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.91	.;D;D;.
Eigen	Uncertain	0.45
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;D;D;D
M_CAP	Pathogenic	0.82	D
MetaRNN	Pathogenic	0.91	D;D;D;D
MetaSVM	Pathogenic	0.95	D
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-3.1	D;.;D;D
REVEL	Pathogenic	0.82
Sift	Uncertain	0.0020	D;.;D;D
Sift4G	Uncertain	0.043	D;D;D;D
Polyphen		0.80	.;.;.;P
Vest4		0.88
MutPred		0.65		Loss of methylation at K273 (P = 0.023);Loss of methylation at K273 (P = 0.023);Loss of methylation at K273 (P = 0.023);Loss of methylation at K273 (P = 0.023);
MVP		0.96
MPC		2.2
ClinPred		0.99	D
GERP RS		4.8
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: rs1555212016; hg19: chr12-121432070;