Definition: 9th chromosome appears three times (trisomy) rather than twice in some cells of the body. The term "mosaic" indicates that some cells contain the extra chromosome 9, while others have the normal chromosomal pair.
Etiology: Errors during meiosis or mitosis
Diagnosis: Take samples from multiple tissues for diagnosis
Clinical features: Associated symptoms and findings may vary greatly in range and severity, depending on the percentage of cells with the extra chromosome.
Growth deficiency before birth, mental retardation, congenital heart defects, craniofacial abnormalities (sloping forehead, bulbous nose, short palpebral fissures, deeply set eyes, and low-set ears, small jaw, large fontanels), musculoskeletal, genital, kidney issues.