46,XX/47XX, + 14 mosaicism in a liveborn infant

Area of Science:

• Genetics
• Human Genetics
• Medical Genetics

Background:

• Mosaic trisomy, characterized by the presence of an extra chromosome in some cells, can lead to a spectrum of developmental outcomes.
• Chromosome 14 abnormalities, including partial or full trisomy, are associated with distinct phenotypic features.
• Atypical D trisomy cases present diagnostic challenges due to variable expressivity and overlapping features.

Observation:

• A liveborn infant with 46,XX/47,XX,+14 mosaicism was identified.
• The infant exhibited a constellation of dysmorphic features and developmental anomalies.
• These features were compared to previously reported cases of trisomy 14 and atypical D trisomy.

Findings:

• The infant shared common features with trisomy 14 and atypical D trisomy cases.
• Key features included developmental retardation, specific facial dysmorphia (wide flat nose, large mouth), short neck, low-set ears, retrognathia, digital anomalies, palatal anomalies, and cryptorchidism.
• The findings suggest a potential link between XX, +14 mosaicism and the observed phenotype.

Implications:

• This case contributes to the understanding of phenotypic variability in chromosome 14 abnormalities.
• It highlights the importance of cytogenetic analysis in diagnosing complex congenital anomalies.
• Further research is needed to delineate the full spectrum of features associated with XX, +14 mosaicism.