rs1456161420

Positions:

• chr16-67169277-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 6P and 1B. PVS1_Moderate PM2 PP5_Moderate BS2_Supporting

The NM_001374675.1(HSF4):​c.1255-2A>G variant causes a splice acceptor change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,206 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: HSF4 NM_001374675.1 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 2.17

Genes affected

HSF4 (HGNC:5227): (heat shock transcription factor 4) Heat-shock transcription factors (HSFs) activate heat-shock response genes under conditions of heat or other stresses. HSF4 lacks the carboxyl-terminal hydrophobic repeat which is shared among all vertebrate HSFs and has been suggested to be involved in the negative regulation of DNA binding activity. Two alternatively spliced transcripts encoding distinct isoforms and possessing different transcriptional activity have been described. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.046653144 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.7, offset of 6, new splice context is: cggttctcacgcggatgcAGccc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-67169277-A-G is Pathogenic according to our data. Variant chr16-67169277-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 459607.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS2: High AC in GnomAdExome4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HSF4	NM_001374675.1	c.1255-2A>G		splice_acceptor_variant		ENST00000521374.6	NP_001361604.1
HSF4	NM_001040667.3	c.1255-2A>G		splice_acceptor_variant			NP_001035757.1
HSF4	NM_001374674.1	c.1165-2A>G		splice_acceptor_variant			NP_001361603.1
HSF4	NM_001538.4	c.1165-2A>G		splice_acceptor_variant			NP_001529.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HSF4	ENST00000521374.6	c.1255-2A>G		splice_acceptor_variant		1	NM_001374675.1	ENSP00000430947	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000201 AC: 5 AN: 248464 Hom.: 0 AF XY: 0.00000741 AC XY: 1 AN XY: 134990

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000145

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461206 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726876

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000112

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cataract 5 multiple types Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 06, 2020

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in HSF4 are known to be pathogenic (PMID: 15959809). This variant has not been reported in the literature in individuals with HSF4-related conditions. ClinVar contains an entry for this variant (Variation ID: 459607). This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 13 of the HSF4 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Pathogenic	0.18
CADD	Pathogenic	30
DANN	Uncertain	0.99
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Uncertain	0.76	D
MutationTaster	Benign	1.0	D;D;D;D
GERP RS		4.6

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.82		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.82		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1456161420; hg19: chr16-67203180;