Objective: To present a case of partial 6q trisomy diagnosed prenatally.
Method: A 28-year-old woman underwent genetic amniocentesis at 23 weeks of gestation on the detection of an enlarged nuchal fold (8.5 mm), which was the only clinical abnormality on routine ultrasound examination. Fetal karyotyping revealed a partial trisomy 6q (q21-q22) caused by a balanced maternal chromosomal insertion.
Results: A female infant was delivered at 38 weeks of gestation. At birth, minor dysmorphisms were recorded, which included low set ears, macrocephaly and a webbed neck. At 17 months of age, neurological developmental assessment was normal.
Conclusions: The appearance of phenotypic expression and clinical outcome of partial 6q trisomy depends on the specific chromosomal region involved in the segmental aneusomy.