12-120978554-A-G

Position:

• chr12-120978554-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1_Supporting PP4_Moderate PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The c.215A>G variant in the HNF1 homeobox A gene, HNF1A, is a single nucleotide variant within the promoter of NM_000545.8. This variant is located within a region of the promoter (–c.-209 to c.-227) of HNF1A which is defined as critical for the protein’s function by the ClinGen MDEP (PM1_Supporting). 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 HNF1A-MODY (MODY probability calculator result >50%, negative genetic testing for HNF4A and SU sensitivity) (PP4_Moderate; internal lab contributors). This variant segregated with diabetes with 2 informative meioses in a single family; however, this does not meet the thresholds for PP1 set by the ClinGen MDEP (internal lab contributors). In summary, c.-215A>G meets the criteria to be classified as a variant of uncertain significance for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 2.1.0, approved 8/11/2023): PP4_Moderate, PM1_Supporting, PM2_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA2740067583/MONDO:0015967/017

• Frequency: Genomes: not found (cov: 32)
• Consequence: HNF1A NM_000545.8 5_prime_UTR
• Clinical Significance: Uncertain significance reviewed by expert panel U:1
• Conservation: PhyloP100: 4.68

Genes affected

HNF1A (HGNC:11621): (HNF1 homeobox A) The protein encoded by this gene is a transcription factor required for the expression of several liver-specific genes. The encoded protein functions as a homodimer and binds to the inverted palindrome 5'-GTTAATNATTAAC-3'. Defects in this gene are a cause of maturity onset diabetes of the young type 3 (MODY3) and also can result in the appearance of hepatic adenomas. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Apr 2015]

HNF1A-AS1 (HGNC:26785): (HNF1A antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HNF1A	NM_000545.8	c.-215A>G		5_prime_UTR_variant	1/10	ENST00000257555.11	NP_000536.6
HNF1A	NM_001306179.2	c.-215A>G		5_prime_UTR_variant	1/10		NP_001293108.2
HNF1A	NM_001406915.1	c.-215A>G		5_prime_UTR_variant	1/9		NP_001393844.1
HNF1A	XM_024449168.2	c.-215A>G		5_prime_UTR_variant	1/9		XP_024304936.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HNF1A	ENST00000257555	c.-215A>G		5_prime_UTR_variant	1/10	1	NM_000545.8	ENSP00000257555.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 3

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Monogenic diabetes Uncertain:1

Uncertain significance, reviewed by expert panel

curation

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Mar 31, 2024

The c.215A>G variant in the HNF1 homeobox A gene, HNF1A, is a single nucleotide variant within the promoter of NM_000545.8. This variant is located within a region of the promoter (c.-209 to c.-227) of HNF1A which is defined as critical for the protein’s function by the ClinGen MDEP (PM1_Supporting). 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 HNF1A-MODY (MODY probability calculator result >50%, negative genetic testing for HNF4A and SU sensitivity) (PP4_Moderate; internal lab contributors). This variant segregated with diabetes with 2 informative meioses in a single family; however, this does not meet the thresholds for PP1 set by the ClinGen MDEP (internal lab contributors). In summary, c.-215A>G meets the criteria to be classified as a variant of uncertain significance for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 2.1.0, approved 8/11/2023): PP4_Moderate, PM1_Supporting, PM2_Supporting. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.30
CADD	Benign	21
DANN	Benign	0.93

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-121416357;