Trisomy 18 is a relatively common autosomal trisomy syndrome. It is due to either full or partial presence of an extra copy of chromosome 18. Its prevalence correlates positively with advanced maternal age. Affected infants usually exhibit a variable pattern of anomalies including growth restriction, marked psychomotor and cognitive disability and an array of physical findings including characteristic craniofacial features, clenched fists with overriding fingers, small fingernails, underdeveloped thumbs, short sternum and heart and kidney anomalies. The majority of these infants die within the first year of life; only 5% to 10% of them survive longer. Their death is primarily due to cardio-respiratory failure. In this case report of trisomy 18 we tried to highlight the importance of antenatal diagnosis and to emphasize the need for proper counseling at different points of time starting from the moment the condition is suspected until the point when diagnosis is confirmed and thereafter.
Key words: Aneuploidy; Counseling; Edward’s syndrome; Prenatal diagnosis; Trisomy 18