*3.3. Bioinformatic Studies*

The heterozygous mutation (c.485G>A) causes a change in the physical–chemical properties of the protein because of the substitution of the amino acid arginine for glutamine (Arg162Gln). This variant affects the second C2H2 domain with the zinc-finger structure of IKAROS protein (ZF2, amino acids 145–167), a residue essential for DNA binding. All evaluated in silico predictors of protein damage determined a deleterious effect for the IKAROS protein (Table 3).

**Figure 2.** Genetic analysis of the *IKZF1* gene. (**A**) Next-generation sequencing of the patient revealed a heterozygous *missense* variant (c.485G>A) in exon 5 of the *IKZF1* gene, in chromosome 7p12.2, that results in a substitution of arginine to glutamine (p.Arg162Gln). Electropherograms of the Sanger sequencing performed in the patient's father (**B**) and mother (**C**) demonstrated homozygosity for G at position c.485 of exon 5 of *IKZF1*.

**Table 3.** Results of the in silico predictors of the effect of the variant. MutationTaster (values range from 0 to 1): probability close to 1 indicates greater confidence in the prediction. DANN (Deleterious Annotation of Genetic Variants using Neural Networks; values range from 0 to 1): the highest values are potentially the most pathogenic. FATHMM MKL (Functional Analysis through Hidden Markov Models; values range from 0 to 1): the highest values are potentially the most pathogenic. Coding and non-coding variants are scored independently.

