chr4-87046750-A-G

Position:

• chr4-87046750-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001166693.3(AFF1):​c.215A>G​(p.Glu72Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: AFF1 NM_001166693.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.91

Genes affected

AFF1 (HGNC:7135): (ALF transcription elongation factor 1) This gene encodes a member of the AF4/ lymphoid nuclear protein related to the Fragile X E syndrome (FRAXE) family of proteins, which have been implicated in human childhood lymphoblastic leukemia, fragile chromosome X intellectual disability, and ataxia. It is the prevalent mixed-lineage leukemia fusion gene associated with spontaneous acute lymphoblastic leukemia. Members of this family have three conserved domains: an N-terminal homology domain, an AF4/ lymphoid nuclear protein domain, and a C-terminal homology domain. The protein functions as a regulator of RNA polymerase II-mediated transcription through elongation and chromatin remodeling functions. Through RNA interference screens, this gene has been shown to promote the expression of CD133, a plasma membrane glycoprotein required for leukemia cell survival. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.89

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AFF1	NM_001166693.3	c.215A>G	p.Glu72Gly	missense_variant	4/21	ENST00000395146.9	NP_001160165.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AFF1	ENST00000395146.9	c.215A>G	p.Glu72Gly	missense_variant	4/21	2	NM_001166693.3	ENSP00000378578	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 08, 2023

The c.215A>G (p.E72G) alteration is located in exon 4 (coding exon 3) of the AFF1 gene. This alteration results from a A to G substitution at nucleotide position 215, causing the glutamic acid (E) at amino acid position 72 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.33
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.35	.;T;T;T;D;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D
MetaSVM	Uncertain	-0.0078	T
MutationAssessor	Pathogenic	2.9	.;.;.;.;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.45	T
PROVEAN	Pathogenic	-4.7	D;D;D;D;D;.
REVEL	Pathogenic	0.66
Sift	Uncertain	0.0030	D;D;D;D;D;.
Sift4G	Uncertain	0.010	D;D;D;D;D;D
Polyphen		1.0	.;.;.;.;D;.
Vest4		0.57
MutPred		0.77		.;.;.;.;Loss of disorder (P = 0.0963);Loss of disorder (P = 0.0963);
MVP		0.82
MPC		0.36
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.54
gMVP		0.29

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

LitVar

Other links and lift over

dbSNP: rs1356923618; hg19: chr4-87967902;