Partial mosaic trisomy 5: a new case report with ocular involvement.

Area of Science:

• Genetics
• Clinical Medicine
• Developmental Biology

Background:

• De novo partial trisomy 5 syndrome is a rare chromosomal disorder.
• Ocular manifestations are infrequently reported in trisomy 5.
• Understanding the clinical spectrum is crucial for diagnosis and management.

Observation:

• A male patient presented with 80% mosaicism for a small marker chromosome derived from chromosome 5.
• Clinical features included posterior iridolenticular synechia, high hyperopia, epicanthic folds, hypertelorism, developmental delay, speech absence, macrocephaly, micrognathia, ear anomalies, and polydactyly.
• Karyotype confirmed 46, XY/47, XY +mar, with fluorescence in situ hybridization (FISH) using a chromosome 5 painting probe.

Findings:

• This case represents a novel description of ocular involvement in trisomic 5 subjects, with only two prior cases documented.
• The patient exhibited a distinct set of dysmorphic and developmental features associated with the partial trisomy 5.
• The marker chromosome was confirmed to be of chromosome 5 origin.

Implications:

• This report expands the known clinical phenotype of de novo partial trisomy 5 syndrome.
• It underscores the importance of detailed ophthalmological examination in patients with chromosomal abnormalities.
• Further research is needed to elucidate the genotype-phenotype correlations in partial trisomy 5.