Our verdict is Likely benign. Variant got -2 ACMG points: 3P and 5B. PM2PP2BP4BS2
The NM_006060.6(IKZF1):c.4G>C(p.Asp2His) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,460,854 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).
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]
Verdict is Likely_benign. Variant got -2 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
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 autoimmune disease, pancytopenia due to IKZF1 mutations.
BP4
Computational evidence support a benign effect (MetaRNN=0.29733285).
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);Gain of catalytic residue at D4 (P = 0.4795);