First Detection of 1p36 Deletion by Whole-Exome Sequencing in a Tunisian Patient.

STUDY

OBJECTIVE

We reported a rare case of 1p36 deletion syndrome diagnosed using whole-exome sequencing (WES) in a Tunisian neonate, and to highlight the utility of WES in detecting structural variants, particularly in resource-limited settings.

METHODS

Clinical and genetic investigations were conducted on a female neonate presenting with a severe polymalformative syndrome. WES was performed to detect potential genetic abnormalities, followed by validation through fluorescence in situ hybridization (FISH). Variant annotation and classification were done in accordance with ACMG guidelines.

RESULTS

WES identified a heterozygous interstitial deletion in the 1p36 region, spanning 11.64 Mb and affecting 155 coding genes, including key genes such as MMP23B, GABRD, SKI, PRDM16, KCNAB2, RERE, UBE4B, and CASZ1. The deletion was classified as pathogenic, and FISH analysis confirmed its presence. Clinically, the patient exhibited intrauterine growth restriction, neonatal epilepsy, craniofacial dysmorphia, congenital heart defect, and agenesis of the corpus callosum.

CONCLUSION

This is the first reported case in Tunisia of a 1p36 deletion identified via short-read WES. The findings support the expanding role of WES in structural variant detection and underscore its diagnostic value, especially in settings with limited access to chromosomal microarray or genome sequencing technologies.