1-3858719-T-A

Variant names:

• chr1-3858719-T-A
• rs781186974
• NM_004402.4:c.116T>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_004402.4(DFFB):​c.116T>A​(p.Leu39His) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000205 in 1,461,546 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L39R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: DFFB NM_004402.4 missense, splice_region
• Scores: Splicing: ADA: 0.2606
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.17
• Publications: 0 publications found

Genes affected

DFFB (HGNC:2773): (DNA fragmentation factor subunit beta) Apoptosis is a cell death process that removes toxic and/or useless cells during mammalian development. The apoptotic process is accompanied by shrinkage and fragmentation of the cells and nuclei and degradation of the chromosomal DNA into nucleosomal units. DNA fragmentation factor (DFF) is a heterodimeric protein of 40-kD (DFFB) and 45-kD (DFFA) subunits. DFFA is the substrate for caspase-3 and triggers DNA fragmentation during apoptosis. DFF becomes activated when DFFA is cleaved by caspase-3. The cleaved fragments of DFFA dissociate from DFFB, the active component of DFF. DFFB has been found to trigger both DNA fragmentation and chromatin condensation during apoptosis. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene but the biological validity of some of these variants has not been determined. [provided by RefSeq, Sep 2013]

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.814

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DFFB	NM_004402.4	c.116T>A	p.Leu39His	missense_variant, splice_region_variant	Exon 2 of 7	ENST00000378209.8	NP_004393.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DFFB	ENST00000378209.8	c.116T>A	p.Leu39His	missense_variant, splice_region_variant	Exon 2 of 7	1	NM_004402.4	ENSP00000367454.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461546 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727102

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53222

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111916

Other (OTH) AF: 0.00 AC: 0 AN: 60376

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.49
BayesDel_addAF	Uncertain	0.057	T
BayesDel_noAF	Benign	-0.16
CADD	Pathogenic	26
DANN	Uncertain	0.98
DEOGEN2	Benign	0.15	T;T;T;.
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.71	T;T;T;T
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.81	D;D;D;D
MetaSVM	Benign	-0.50	T
MutationAssessor	Uncertain	2.7	.;.;M;.
PhyloP100		5.2
PrimateAI	Uncertain	0.51	T
PROVEAN	Pathogenic	-4.8	.;D;D;D
REVEL	Uncertain	0.35
Sift	Uncertain	0.0010	.;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0	.;D;D;.
Vest4		0.72
MutPred		0.64		Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);
MVP		0.61
MPC		0.93
ClinPred		0.99	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.54
gMVP		0.72
Mutation Taster		=58/42	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.26
dbscSNV1_RF	Benign	0.63
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs781186974; hg19: chr1-3775283;