chr20-44413795-C-T

Position:

• chr20-44413795-C-T

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PP4_Moderate PVS1 PM2_Supporting PS4 PP1_Strong

This summary comes from the ClinGen Evidence Repository: The c.421C>T variant in the hepatocyte nuclear factor 4-alpha gene, HNF4A, results in a premature termination at codon 141 (p.(Arg141Ter)) of NM_175914.5. This variant, located in biologically-relevant exon 4 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), and was identified in at least 10 unrelated individuals with non-autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4; PMID:9294105, internal lab contributors). Three individuals had a clinical history highly specific for HNF4A-MODY monogenic diabetes (MODY probability calculator result >50%, negative genetic testing for HNF1A, and response to low-dose sulfonylureas) (PP4_Moderate; internal lab contributors). This variant also segregated with diabetes, with at least seven informative meioses in two families (PP1_Strong; PMID:9294105, internal lab contributor). In summary, c.421C>T 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, PP1_Strong, PS4, PP4_Moderate, PM2_Supporting). LINK:https://erepo.genome.network/evrepo/ui/classification/CA120194/MONDO:0015967/085

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF4A NM_175914.5 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:4
• Conservation: PhyloP100: 5.01

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]

ACMG classification

Verdict is Pathogenic. Variant got 19 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HNF4A	NM_175914.5	c.421C>T	p.Arg141Ter	stop_gained	4/10	ENST00000316673.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HNF4A	ENST00000316673.9	c.421C>T	p.Arg141Ter	stop_gained	4/10	1	NM_175914.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: reviewed by expert panel

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Sep 04, 2023	Experimental studies have shown that this premature translational stop signal affects HNF4A function (PMID: 10606640). This sequence change creates a premature translational stop signal (p.Arg141*) in the HNF4A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HNF4A are known to be pathogenic (PMID: 20164212, 23275527, 23348805, 24097065). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with maturity onset diabetes of the young (PMID: 9294105). This variant is also known as R154X. ClinVar contains an entry for this variant (Variation ID: 9211). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Aug 17, 2021	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 with clinical features associated with this gene. Assessment of experimental evidence suggests this variant results in abnormal protein function. Experiments indicate this variant impairs transcriptional activity (PMID: 10606640, 11435618). -

Monogenic diabetes Pathogenic:1

Pathogenic, reviewed by expert panel

curation

ClinGen Monogenic Diabetes Variant Curation Expert Panel

May 09, 2024

The c.421C>T variant in the hepatocyte nuclear factor 4-alpha gene, HNF4A, results in a premature termination at codon 141 (p.(Arg141Ter)) of NM_175914.5. This variant, located in biologically-relevant exon 4 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), and was identified in at least 10 unrelated individuals with non-autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4; PMID: 9294105, internal lab contributors). Three individuals had a clinical history highly specific for HNF4A-MODY monogenic diabetes (MODY probability calculator result >50%, negative genetic testing for HNF1A, and response to low-dose sulfonylureas) (PP4_Moderate; internal lab contributors). This variant also segregated with diabetes, with at least seven informative meioses in two families (PP1_Strong; PMID: 9294105, internal lab contributor). In summary, c.421C>T 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, PP1_Strong, PS4, PP4_Moderate, PM2_Supporting). -

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

Pathogenic, no assertion criteria provided

literature only

OMIM

Jul 01, 2001

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	44
DANN	Uncertain	1.0
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.95	D
MutationTaster	Benign	1.0	A;A;A;A;A
Vest4		0.99
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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: rs137853335; hg19: chr20-43042435;