Akademik Veri Yönetim Sistemi
European Human Genetics Conference, Berlin, Almanya, 1 - 04 Haziran 2024, ss.1
Background/Objectives: Phelan-McDermid syndrome (PMS) is a rare neurodevelopmental
disorder characterized by diverse phenotypes, including intellectual disability, delayed
speech, and autistic features. PMS is caused by either pathological variants or contiguous
gene deletions on chromosome 22q13, encompassing the SHANK3 gene. This study aims to
present clinical, molecular/cytogenetic findings of four cases highlighting PMS's multifaceted
nature and complexity.
Methods: The diagnosis of PMS in cases was achieved through the analysis of blood
samples using chromosome analysis, Fluorescence in situ Hybridization (FISH), arraycomparative Genomic Hybridization (CGH), exome sequencing (ES) (covering copy number
variations), and Sanger sequencing for confirmation.
Results: Three patients had multiple congenital anomalies, developmental delay, and facial
dysmorphic features, while the fourth patient had only epilepsy and autism. In the first case,
chromosome analysis was normal, and array-CGH analysis revealed a 5 Mb deletion
involving the SHANK3 gene. In the second case, chromosomal analysis unveiled an
unbalanced de novo inversion at 22q, resulting in a deletion involving the SHANK3 gene. In
the third case, a 2.3 Mb deletion was detected in the 22q13.3 region in the array-CGH study
due to mosaic ring chromosome 22, which was detected in chromosome analysis. In the
fourth case, ES revealed a heterozygous frameshift c.3950_3962del/p.(Arg1317LeufsTer25)
variant in SHANK3 gene.
Conclusion: PMS is a complex neurodevelopmental disorder characterized by diverse
clinical features resulting from various molecular/cytogenetic alterations, including
chromosomal abnormalities and single nucleotide variations. Understanding underlying
genetic mechanisms is cr