7-50382603-G-C

Variant names:

• chr7-50382603-G-C
• rs770551610
• NM_006060.6:c.485G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The NM_006060.6(IKZF1):​c.485G>C​(p.Arg162Pro) 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R162W) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: IKZF1 NM_006060.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 10.0
• Publications: 2 publications found

Genes affected

IKZF1 (HGNC:13176): (IKAROS family zinc finger 1) This gene encodes a transcription factor that belongs to the family of zinc-finger DNA-binding proteins associated with chromatin remodeling. The expression of this protein is restricted to the fetal and adult hemo-lymphopoietic system, and it functions as a regulator of lymphocyte differentiation. Several alternatively spliced transcript variants encoding different isoforms have been described for this gene. Most isoforms share a common C-terminal domain, which contains two zinc finger motifs that are required for hetero- or homo-dimerization, and for interactions with other proteins. The isoforms, however, differ in the number of N-terminal zinc finger motifs that bind DNA and in nuclear localization signal presence, resulting in members with and without DNA-binding properties. Only a few isoforms contain the requisite three or more N-terminal zinc motifs that confer high affinity binding to a specific core DNA sequence element in the promoters of target genes. The non-DNA-binding isoforms are largely found in the cytoplasm, and are thought to function as dominant-negative factors. Overexpression of some dominant-negative isoforms have been associated with B-cell malignancies, such as acute lymphoblastic leukemia (ALL). [provided by RefSeq, May 2014]

IKZF1 Gene-Disease associations (from GenCC):

• pancytopenia due to IKZF1 mutations

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Illumina, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• autoimmune disease

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_006060.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-50382602-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 827710.
• PP2: Missense variant in the IKZF1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 11 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 3.3753 (above the threshold of 3.09). Trascript score misZ: 3.423 (above the threshold of 3.09). GenCC associations: The gene is linked to pancytopenia due to IKZF1 mutations, autoimmune disease.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.795

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IKZF1	NM_006060.6	c.485G>C	p.Arg162Pro	missense_variant	Exon 5 of 8	ENST00000331340.8	NP_006051.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IKZF1	ENST00000331340.8	c.485G>C	p.Arg162Pro	missense_variant	Exon 5 of 8	1	NM_006060.6	ENSP00000331614.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Sep 23, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on IKZF1 function (PMID: 29681510). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. This missense change has been observed in individual(s) with acute lymphoblastic leukemia (PMID: 29681510). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 162 of the IKZF1 protein (p.Arg162Pro).

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	34
DANN	Uncertain	1.0
DEOGEN2	Benign	0.0	.;D;D;T;.;.;.;.;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.89	D;.;D;D;.;D;D;D;.
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.79	D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.47	T
MutationAssessor	Benign	0.0	.;.;.;.;.;.;.;.;.
PhyloP100		10
PrimateAI	Pathogenic	0.96	D
PROVEAN	Benign	0.0	.;.;D;.;D;D;D;D;D
REVEL	Benign	0.0
Sift	Pathogenic	0.0	.;.;D;.;D;D;D;D;D
Sift4G	Pathogenic	0.0	.;.;D;T;D;D;D;D;D
Vest4		0.0
ClinPred		1.0	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.98
gMVP		0.98
Mutation Taster		=5/95	disease causing

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

Other links and lift over

dbSNP: rs770551610; hg19: chr7-50450301;