20-44424059-C-T

Variant names:

• chr20-44424059-C-T
• rs1555817727
• NM_175914.5:c.868C>T

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PP3 PM2_Supporting PS4 PP1_Strong PM5 PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The c.868C>T variant in the hepatic nuclear factor 4-alpha gene, HNF4A, causes an amino acid change of arginine to cysteine at codon 290 (p.(Arg290Cys)) of NM_175914.5. This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.92, which is greater than the MDEP VCEP threshold of 0.70 (PP3). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). This variant was identified in at least 10 unrelated individuals with non- autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4; PMIDs: 32533152, 21683639, internal lab contributors). One of these individuals had a clinical history highly specific for HNF4A-monogenic diabetes (MODY probability calculator result >50%, negative genetic testing for HNF1A, and a family member with the variant with diazoxide-responsive neonatal hyperinsulinemic hypoglycemia) (PP4_Moderate; internal lab contributors). This variant segregated with diabetes, with 20 informative meioses in 8 families (PP1_Strong; internal lab contributors). Another missense variant, c.869G>A p.Arg290His, has been interpreted as pathogenic by the ClinGen MDEP, and p.Arg290Cys has a greater Grantham distance (PM5). In summary, c.868C>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): PP1_Strong, PS4, PP4_Moderate, PM5, PP3, PM2_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA409108070/MONDO:0015967/085

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF4A NM_175914.5 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:3 U:1
• Conservation: PhyloP100: 3.19
• Publications: 1 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 14 ACMG points.

• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM5: For more information check the summary or visit ClinGen Evidence Repository.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HNF4A	NM_175914.5	c.868C>T	p.Arg290Cys	missense_variant	Exon 8 of 10	ENST00000316673.9	NP_787110.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HNF4A	ENST00000316673.9	c.868C>T	p.Arg290Cys	missense_variant	Exon 8 of 10	1	NM_175914.5	ENSP00000315180.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

not provided Pathogenic:2 Uncertain:1

Aug 15, 2023

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (gnomAD); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; In silico analysis, which includes splice predictors and evolutionary conservation, suggests this variant may impact gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 21683639, 27552834, 30447144, 32533152, 23348805, 23803251, 35089870, 36613572) -

Jul 01, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 290 of the HNF4A protein (p.Arg290Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of maturity onset diabetes of the young (PMID: 21683639, 30447144). ClinVar contains an entry for this variant (Variation ID: 447524). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Sep 30, 2016

Athena Diagnostics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Monogenic diabetes Pathogenic:1

Apr 06, 2024

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.868C>T variant in the hepatic nuclear factor 4-alpha gene, HNF4A, causes an amino acid change of arginine to cysteine at codon 290 (p.(Arg290Cys)) of NM_175914.5. This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.92, which is greater than the MDEP VCEP threshold of 0.70 (PP3). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). This variant was identified in at least 10 unrelated individuals with non- autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4; PMIDs: 32533152, 21683639, internal lab contributors). One of these individuals had a clinical history highly specific for HNF4A-monogenic diabetes (MODY probability calculator result >50%, negative genetic testing for HNF1A, and a family member with the variant with diazoxide-responsive neonatal hyperinsulinemic hypoglycemia) (PP4_Moderate; internal lab contributors). This variant segregated with diabetes, with 20 informative meioses in 8 families (PP1_Strong; internal lab contributors). Another missense variant, c.869G>A p.Arg290His, has been interpreted as pathogenic by the ClinGen MDEP, and p.Arg290Cys has a greater Grantham distance (PM5). In summary, c.868C>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): PP1_Strong, PS4, PP4_Moderate, PM5, PP3, PM2_Supporting. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.44	.;.;.;T;.;D;.
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D;D
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Pathogenic	4.1	.;.;.;.;H;H;H
PhyloP100		3.2
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-7.1	D;.;D;.;D;D;D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D;.;D;.;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D
Polyphen		1.0	.;D;D;.;D;D;.
Vest4		0.86
MutPred		0.85		.;.;.;.;Loss of disorder (P = 0.0152);Loss of disorder (P = 0.0152);Loss of disorder (P = 0.0152);
MVP		0.99
MPC		1.2
ClinPred		1.0	D
GERP RS		3.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.89
gMVP		0.84
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.46		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.46		Position offset: 9

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1555817727; hg19: chr20-43052699;