rs1555212359

chr12-120997522-GC-G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000545.8(HNF1A):c.1359del(p.Ser454AlafsTer3) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF1A NM_000545.8 frameshift
• Clinical Significance: Likely pathogenic reviewed by expert panel P:4
• Conservation: PhyloP100: -0.507

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-120997522-GC-G is Pathogenic according to our data. Variant chr12-120997522-GC-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 435427.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HNF1A	NM_000545.8	c.1359del	p.Ser454AlafsTer3	frameshift_variant	7/10	ENST00000257555.11
HNF1A	NM_001306179.2	c.1359del	p.Ser454AlafsTer3	frameshift_variant	7/10
HNF1A	XM_024449168.2	c.1359del	p.Ser454AlafsTer3	frameshift_variant	7/9
HNF1A	NM_001406915.1	c.1309+781del		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HNF1A	ENST00000257555.11	c.1359del	p.Ser454AlafsTer3	frameshift_variant	7/10	1	NM_000545.8	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:4

Revision: reviewed by expert panel

Submissions by phenotype

Monogenic diabetes Pathogenic:1

Likely pathogenic, reviewed by expert panel

curation

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Dec 31, 2021

The c.1359del variant in the HNF1 homeobox A gene, HNF1A, causes a frameshift in the protein at codon 454 (NM_000545.8), adding 3 novel amino acids before encountering a stop codon (p.(Ser454AlafsTer3)). This variant, located in biologically-relevant exon 7 of 10, is predicted to lead to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1; PMID: 23348805). Also, this variant is absent from gnomAD v2.1.1 (PM2_Supporting). In summary, c.1359del meets the criteria to be classified as likely pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 1.0, approved 6/4/2021): PVS1, PM2_Supporting -

Maturity onset diabetes mellitus in young Pathogenic:1

Likely pathogenic, 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 rs1555212359 with MODY3. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jun 10, 2022

This variant is expected to result in the loss of a functional protein. This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). This variant has been identified in at least one individual tested at Athena Diagnostics with clinical features associated with this gene. -

Maturity-onset diabetes of the young type 3 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Jul 31, 2015

- -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555212359; hg19: chr12-121435325;