Interstitial 8p deletion in two patients with the expansion of phenotype and possibility of contribution of PINX1 gene and GATA4 rs3729856 variant in absent nails

The short arm of chromosome 8 is subjected to recurrent genomic imbalances. We aimed to delineate the genotype phenotype correlations to the different 8p deleted segments and predict the candidate gene for absent nails (anonychia). In this study we present two patients with interstitial 8p deletion. The first is a male patient presented with failure to thrive, seizures, hypotonia, absent nails, congenital heart, microcephaly, and hypogenesis of corpus callosum. Array CGH showed 18.6 Mb in 8p23.2p21.3 deletion that involved GATA4 gene. Sequencing for GATA4 gene disclosed likely pathogenic variant in the other allele. The second patient was a female presented with developmental delay, dysmorphic features, microcephaly, hypotonia, atrophic brain, and hypogenesis of corpus callosum. Array CGH showed a 25.6 Mb 8p22p12 deletion. We divided the deleted regions into three parts, and we tried to specify phenotype correlated to each region. We found rs3729856 (Ser378Gly) variant, which is a likely pathological in GATA4 gene, we predict that anonychia in the 1st patient may be due to deletion of one copy of GATA4 gene and mutation in the other allele, also we suggest that PINX1 gene may be a sharing gene for anonychia. Combined karyotype, FISH, array CGH, sequencing analysis, and in silico analysis are crucial in genotype-phenotype correlation.