1q42.12q42.2 Deletion in a Child with Midline Defects and Hypoplasia of the Corpus Callosum

Abstract

Chromosome 1q42.12q42.2 deletions are documented as "disease causing" and show overlapping phenotypes depending on the genes involved in the deletion. In this report, we detected a 5.8-Mb deletion encompassing the chromosome 1q42.12q42.2 region in a 4-year-old boy with hypoplastic corpus callosum, epilepsy, developmental delay, microcephaly, cataract, cleft palate, and skeletal changes. The deletion was de novo. Genotype-phenotype correlations suggest that the major features of 1q42.12q42.2 microdeletion were attributed to the genes with a high probability of loss-of-function intolerance score in this deletion, namely LBR, ENAH, ACBD3, LIN9, ITPKB, CDC42BPA, ARF1, TAF5L, GALNT2, SPRTN, and EGLN1 along with GNPAT.

Keywords: 1q42.12q42.2 deletion; GNPAT; LBR; pLI score.

Fig. 1

Anteroposterior view of the proband's wrist showing epiphyseal changes in the long bones. Arrow indicates widened epiphysis.

Fig. 2

The comparison of deleted regions across different studies with the current study. The deletion region in our case overlaps with the deletion regions reported by Garza-Flores et al. [2017] and Filges et al. [2010]. No overlap was observed with deletion regions reported by Rosenfeld et al. [2011]. The genes with a high probability of loss-of-function intolerance (pLi) score in this deletion are: LBR, ENAH, ACBD3, LIN9, ITPKB, CDC42BPA, ARF1, TAF5L, GALNT2, SPRTN, and EGLN1.