2q23.1 microdeletion identified by array comparative genomic hybridisation: an emerging phenotype with Angelman-like...

Area of Science:

• Genetics
• Developmental Biology
• Neurology

Background:

• Genome-wide screening identified novel imbalances in patients with mental retardation.
• A de novo 2q22.3q23.3 deletion was recently described as a microdeletion syndrome.
• Two unrelated patients presented with similar pseudo-Angelman phenotypes due to this deletion.

Discussion:

• The 2q23.1 microdeletion syndrome shares features with Angelman syndrome.
• Clinical manifestations include severe psychomotor retardation, speech impairment, epilepsy, microcephaly, ataxia, and behavioral issues.
• The identified deletion region overlaps by approximately 250 kb in both patients.

Key Insights:

• Array comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), and PCR confirmed the microdeletions.
• The overlapping deleted region at 2q23.1 encompasses the MBD5 and EPC2 genes.
• The SIP1 gene, associated with Mowat-Wilson syndrome, was excluded from the deleted region.

Outlook:

• Haploinsufficiency of MBD5 or EPC2 is hypothesized to cause the observed clinical features.
• Further investigation is required to confirm the role of these genes in the 2q23.1 microdeletion syndrome.
• This genotype-first approach aids in identifying novel genetic syndromes and their associated phenotypes.