Chromosome 22 mosaic monosomy (46,XY/45,XY,-22)

Area of Science:

• Genetics
• Developmental Biology
• Clinical Medicine

Background:

• Mosaic monosomy involves the presence of two or more cell lines with different chromosome complements.
• Monosomy 22, the absence of one copy of chromosome 22, is typically lethal.
• Mosaic forms may allow for survival and present with variable clinical features.

Observation:

• A child presented with mild dysmorphic features and intellectual disability.
• Genetic analysis revealed mosaic monosomy 22.
• Chromosome 22 was missing in 10.5% of lymphocytes and 8.3% of fibroblasts.

Findings:

• This case represents the second documented instance of mosaic monosomy 22.
• The chromosomal abnormality was confirmed through analysis of different cell types.
• The findings highlight the phenotypic variability associated with chromosomal mosaicism.

Implications:

• Understanding mosaic chromosomal abnormalities is crucial for accurate genetic diagnosis.
• This case contributes to the limited literature on monosomy 22 mosaicism.
• Further research is needed to elucidate the long-term outcomes and management strategies for individuals with this rare condition.