NM_175914.5:c.498T>A

Variant names:

• chr20-44414578-T-A
• rs1555815393
• NM_175914.5:c.498T>A
• HNF4A p.Cys166*

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM2_Supporting PVS1

This summary comes from the ClinGen Evidence Repository: The c.498T>A variant in the hepatocyte nuclear factor 4-alpha gene, HNF4A, results in a premature termination at codon 166 (p.(Cys166Ter)) of NM_175914.5. This variant, located in biologically-relevant exon 5 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 in gnomAD v2.1.1 (PM2_Supporting). It was identified in two unrelated individuals with non-autoimmune and non-absolute/near-absolute insulin-deficient diabetes; however, PS4_Moderate cannot be applied because this number is below the ClinGen MDEP threshold (ClinVar ID: 520675). In summary, c.498T>A meets the criteria to be classified as likely pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 2.0.0, approved 10/11/2023): PVS1, PM2_Supporting). LINK:https://erepo.genome.network/evrepo/ui/classification/CA409106015/MONDO:0015967/085

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF4A NM_175914.5 stop_gained
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3
• Conservation: PhyloP100: -1.28
• 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: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• 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

Specifications for HNF4A are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Likely_pathogenic. The variant received 9 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.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HNF4A	NM_175914.5	MANE Select	c.498T>A	p.Cys166*	stop_gained	Exon 5 of 10	NP_787110.2
	HNF4A	NM_000457.6		c.564T>A	p.Cys188*	stop_gained	Exon 5 of 10	NP_000448.3
	HNF4A	NM_001258355.2		c.543T>A	p.Cys181*	stop_gained	Exon 6 of 11	NP_001245284.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HNF4A	ENST00000316673.9	TSL:1 MANE Select	c.498T>A	p.Cys166*	stop_gained	Exon 5 of 10	ENSP00000315180.4	P41235-5
	HNF4A	ENST00000316099.10	TSL:1	c.564T>A	p.Cys188*	stop_gained	Exon 5 of 10	ENSP00000312987.3	P41235-1
	HNF4A	ENST00000415691.2	TSL:1	c.564T>A	p.Cys188*	stop_gained	Exon 5 of 10	ENSP00000412111.1	P41235-2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
2	-	-	Maturity-onset diabetes of the young (2)
1	-	-	Monogenic diabetes (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	26
DANN	Uncertain	0.99
Eigen	Benign	-0.34
Eigen_PC	Benign	-0.68
FATHMM_MKL	Benign	0.27	N
PhyloP100		-1.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7
Mutation Taster		=0/200	disease causing (ClinVar)

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs1555815393;

hg19: chr20-43043218;