Partial trisomy D: a diagnostic and cytogenetic dilemma

Area of Science:

• Genetics
• Developmental Biology
• Clinical Medicine

Background:

• Congenital abnormalities and psychomotor retardation in infants can stem from various genetic factors.
• Chromosomal abnormalities are a significant cause of developmental disorders.
• Understanding specific chromosomal alterations is crucial for diagnosing and managing genetic conditions.

Observation:

• An 18-month-old female presented with psychomotor retardation and multiple congenital abnormalities.
• Karyotype analysis revealed 47 chromosomes in the proposita's lymphocytes and fibroblasts.
• Parental chromosomal analyses were normal, indicating a de novo event.

Findings:

• The proposita's karyotype showed an extra marker chromosome, identified as a deletion of chromosome 14 or 15.
• This chromosomal anomaly suggests a partial trisomy D.
• Comparison with existing literature indicates no clear clinical syndrome associated with this specific partial trisomy D.

Implications:

• This case highlights the complexity of chromosomal abnormalities in developmental disorders.
• Further investigation is required to delineate the phenotypic spectrum of partial trisomy D.
• Accurate genetic diagnosis is essential for genetic counseling and understanding disease mechanisms.