20-44419771-CG-C

Variant names:

• chr20-44419771-CG-C
• rs1555816642
• NM_175914.5:c.724delG

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PP4 PM2_Supporting PVS1

This summary comes from the ClinGen Evidence Repository: The c.724del variant in the hepatic nuclear factor 4-alpha gene, HNF4A, causes a frameshift in the protein at codon 242 in NM_175914.5, adding 39 novel amino acids before encountering a stop codon (p.(Val242Cysfs*39)). 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). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). This variant was identified in an individual with a clinical history highly specific for HNF4A-monogenic diabetes (MODY probability calculator result >50%, negative genetic testing for HNF1A) (PP4; internal lab contributors). In summary, c.724del meets the criteria to be classified as pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 2.0.0, approved 10/11/2023): PVS1, PP4, PM2_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA658658870/MONDO:0015967/085

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF4A NM_175914.5 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:3
• Conservation: PhyloP100: 9.99
• Publications: 0 publications found

Genes affected

HNF4A (HGNC:5024): (hepatocyte nuclear factor 4 alpha) The protein encoded by this gene is a nuclear transcription factor which binds DNA as a homodimer. The encoded protein controls the expression of several genes, including hepatocyte nuclear factor 1 alpha, a transcription factor which regulates the expression of several hepatic genes. This gene may play a role in development of the liver, kidney, and intestines. Mutations in this gene have been associated with monogenic autosomal dominant non-insulin-dependent diabetes mellitus type I. Alternative splicing of this gene results in multiple transcript variants encoding several different isoforms. [provided by RefSeq, Apr 2012]

HNF4A Gene-Disease associations (from GenCC):

• maturity-onset diabetes of the young type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
• monogenic diabetes

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• diabetes mellitus, noninsulin-dependent

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• Fanconi renotubular syndrome 4 with maturity-onset diabetes of the young

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, G2P
• hyperinsulinism due to HNF4A deficiency

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• maturity-onset diabetes of the young

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: 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_175914.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HNF4A	NM_175914.5	MANE Select	c.724delG	p.Val242CysfsTer39	frameshift	Exon 7 of 10	NP_787110.2
	HNF4A	NM_000457.6		c.790delG	p.Val264CysfsTer39	frameshift	Exon 7 of 10	NP_000448.3
	HNF4A	NM_001258355.2		c.769delG	p.Val257CysfsTer39	frameshift	Exon 8 of 11	NP_001245284.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HNF4A	ENST00000316673.9	TSL:1 MANE Select	c.724delG	p.Val242CysfsTer39	frameshift	Exon 7 of 10	ENSP00000315180.4
	HNF4A	ENST00000316099.10	TSL:1	c.790delG	p.Val264CysfsTer39	frameshift	Exon 7 of 10	ENSP00000312987.3
	HNF4A	ENST00000415691.2	TSL:1	c.790delG	p.Val264CysfsTer39	frameshift	Exon 7 of 10	ENSP00000412111.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: reviewed by expert panel

Submissions by phenotype

Maturity onset diabetes mellitus in young Pathogenic:1

Oct 20, 2018

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.724delG pathogenic mutation, located in coding exon 7 of the HNF4A gene, results from a deletion of one nucleotide at nucleotide position 724, causing a translational frameshift with a predicted alternate stop codon (p.V242Cfs*39). This mutation was reported in a maturity-onset diabetes of the young family (Colclough K et al. Hum. Mutat., 2013 May;34:669-85). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation.

Monogenic diabetes Pathogenic:1

Jan 22, 2024

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.724del variant in the hepatic nuclear factor 4-alpha gene, HNF4A, causes a frameshift in the protein at codon 242 in NM_175914.5, adding 39 novel amino acids before encountering a stop codon (p.(Val242Cysfs*39)). 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). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). This variant was identified in an individual with a clinical history highly specific for HNF4A-monogenic diabetes (MODY probability calculator result >50%, negative genetic testing for HNF1A) (PP4; internal lab contributors). In summary, c.724del meets the criteria to be classified as pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 2.0.0, approved 10/11/2023): PVS1, PP4, PM2_Supporting.

not provided Pathogenic:1

Sep 30, 2016

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		10
Mutation Taster		=1/199	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: rs1555816642; hg19: chr20-43048411;