chr20-44419790-T-C

Variant names:

• chr20-44419790-T-C
• rs1555816654
• NM_175914.5:c.740T>C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PP1_Moderate PP4_Moderate PP3 PM2_Supporting PS4

This summary comes from the ClinGen Evidence Repository: The c.740T>C variant in the hepatocyte nuclear factor 4-alpha gene, HNF4A, causes an amino acid change of leucine to proline at codon 247 (p.(Leu247Pro)) of NM_175914.5. This variant is absent in gnomAD v2.1.1 (PM2_Supporting) and is predicted to be deleterious by computational evidence, with a REVEL score of 0.979​, which is greater than the MDEP VCEP threshold of 0.70 (PP3). This variant was identified in seven unrelated individuals with non-autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4; PMID:23771925, internal lab contributors). 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, and response to low-dose SU ) (PP4_Moderate; internal lab contributors). This variant was segregated with diabetes, with three informative meioses in two families (PP1_Moderate; internal lab contributors). In summary, c.733G>C 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): PS4, PP1_moderate, PP3, PP4_moderate, PM2_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA409107461/MONDO:0015967/085

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF4A NM_175914.5 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:2 U:2
• Conservation: PhyloP100: 8.01

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 10 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.
• 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.740T>C	p.Leu247Pro	missense_variant	Exon 7 of 10	ENST00000316673.9	NP_787110.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HNF4A	ENST00000316673.9	c.740T>C	p.Leu247Pro	missense_variant	Exon 7 of 10	1	NM_175914.5	ENSP00000315180.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2 Uncertain:2

Revision: reviewed by expert panel

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 25, 2020	Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Identified in one patient with maturity onset diabetes of the young, however, family segregation and functional studies were not performed; please note that this variant is reported using alternate nomenclature L260P (Pihoker et al., 2013); This variant is associated with the following publications: (PMID: 23771925) -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 22, 2025	This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 247 of the HNF4A protein (p.Leu247Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with maturity onset diabetes of the young (PMID: 23771925, 34789499). This variant is also known as c.779T>C p.L260P. ClinVar contains an entry for this variant (Variation ID: 435438). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on HNF4A protein function. 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. -

Monogenic diabetes Pathogenic:1

Pathogenic, reviewed by expert panel

curation

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Aug 30, 2024

The c.740T>C variant in the hepatocyte nuclear factor 4-alpha gene, HNF4A, causes an amino acid change of leucine to proline at codon 247 (p.(Leu247Pro)) of NM_175914.5. This variant is absent in gnomAD v2.1.1 (PM2_Supporting) and is predicted to be deleterious by computational evidence, with a REVEL score of 0.979, which is greater than the MDEP VCEP threshold of 0.70 (PP3). This variant was identified in seven unrelated individuals with non-autoimmune and non-absolute/near-absolute insulin-deficient diabetes (PS4; PMID:23771925, internal lab contributors). 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, and response to low-dose SU ) (PP4_Moderate; internal lab contributors). This variant was segregated with diabetes, with three informative meioses in two families (PP1_Moderate; internal lab contributors). In summary, c.733G>C 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): PS4, PP1_moderate, PP3, PP4_moderate, PM2_Supporting. -

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

Likely pathogenic, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Apr 29, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.53	.;.;.;D;.;D;.
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.1	.;.;.;.;H;H;H
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-5.8	D;.;D;.;D;D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;.;D;.;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D
Polyphen		1.0	.;D;D;.;D;D;.
Vest4		0.99
MutPred		0.88		.;.;.;.;Loss of stability (P = 0.02);Loss of stability (P = 0.02);Loss of stability (P = 0.02);
MVP		0.99
MPC		1.3
ClinPred		1.0	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1555816654; hg19: chr20-43048430;