## 4 Discussion  
In this study, we analyzed CNVs associated with the different phenotypes (plaques vs. pustules) and predominant locations of psoriasis (scalp, non-scalp, and palmoplantar plaques) as well as with anti-TNF-induced PPP. CNVs are known to be involved in psoriasis pathogenesis and the response to biologics treatments; however, few studies have studied characteristic CNVs of each type of psoriasis because most of the studies focused on classic trunk and limbs plaque psoriasis [18; 19; 20; 21; 22]. To our knowledge, this is the first study that analyzes CNVs associated with different types of psoriasis (including special localizations such as scalp and palmoplantar psoriasis) through the direct study of psoriatic tissue. A previous study genotyping IL36 RN, CARD14, and AP1S3 failed to find CNVs associated with PPP in those genes (N = 258) [9]. By these results, we did not find any CNV differentially associated with PPP skin lesions concerning other psoriasis phenotypes. Neither did we find CNV differences between the different locations of psoriasis. Therefore, other genetic factors or non-genetic differences, such as epigenetic changes or even protein modifications, could explain the etiopathogenesis of the different clinical phenotypes found in psoriasis. We determined that the studied phenotypic variations of psoriasis are not related to underlying CNV changes, suggesting that other types of non-genetic regulations may be involved and should be carefully studied. To detect CNVs associated with each type of psoriasis, further analysis should be performed including the skin samples of healthy volunteers. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Comparison** & **Chromosome Location** & **Adj. \(p\)** & **Log2 Ratio \#** & \begin{tabular}{c} **Length** \\ **(Base Pairs)** \\ \end{tabular} & **Genes** \\ \hline \multirow{3}{*}{**Idiopathic psoriasis (N = 39) vs. induced psoriasisiform reactions** (N = 6)} & chr8:100000001-10075000 & 0.045 & \(-\)0.165 & 750,000 & \begin{tabular}{c} _VPS13B_, _MIR599_, _MIR875_ \\ \end{tabular} \\ \cline{1-1}  & \
\begin{tabular}{c} Chr15:79250001- \\ 79350000 \\ \end{tabular} & 0.044 & 0.177 & 100,000 &
\begin{tabular}{c} _RASGFR1_, _LOC100129540_ \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of significant CNVs associated with anti-TNF-induced psoriasisiform reactions. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Comparison** & **Genes ID** & **Gene Name** & **Function** \\ \hline \multirow{6}{*}{**Idiopathic psoriasis (N = 39) vs. induced psoriasisiform reactions** (N = 6)} & _LOC100129540_ & Uncharacterized LOC100129540 & \begin{tabular}{c} Related to coronary heart disease \\ and bipolar disorder \\ \end{tabular} \\ \cline{2-4}  & _MIR599_ & MicroRNA 599 & \begin{tabular}{c} Post-transcriptional regulation of \\ gene expression \\ \end{tabular} \\ \cline{2-4}  & _MIR875_ & MicroRNA 875 & \begin{tabular}{c} Post-transcriptional regulation of \\ gene expression \\ \end{tabular} \\ \cline{2-4}  & _RASGRF1_ & \begin{tabular}{c} Ras Protein Specific Guanine \\ Nucleotide Releasing Factor 1 \\ \end{tabular} & \begin{tabular}{c} Promotes the exchange of \\ Ras-bound GDP by GTP \\ \end{tabular} \\ \cline{2-4}  & _VPS13_ & \
\begin{tabular}{c} Vacuolar Protein Sorting \\ 13 Homolog A \\ \end{tabular} &
\begin{tabular}{c} Allows the formation or \\ stabilization of ER-mitochondria \\ contact sites which facilitates lipids’ \\ transfer between the ER and \\ mitochondria \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Summary of the genes located on the significant bins obtained and their function. Additionally, we searched for differences in skin CNVs between anti-TNF-induced PPP and different non-induced clinical types of psoriasis, including idiopathic PPP. We found two CNVs that harbor five genes, LOC100129540, MIR599, MIR875 RASGRF1, and VPS13B, which participate in diverse functions such as lipids' transfer or the regulation of gene expression.