A chromosomal disorder caused by an extra copy of chromosome 18. Severe, life-limiting condition with multiple organ abnormalities including heart defects, clenched fists with overlapping fingers, and rocker-bottom feet. Most die before birth or in infancy.

• 1Genetic testing
• 2Clinical evaluation
• 3Family history assessment
• 4Specialized laboratory tests
• 5Imaging studies
• 6Biopsy (if applicable)

Poor. 50% die within first week. 90% die by age 1. Only 5-10% survive to age 1 year with severe disabilities. Girls survive slightly longer than boys. Major organ defects (heart, brain) limit survival. Feeding difficulties common. Some centers offer surgical intervention for heart defects with variable outcomes. Quality of life focus important. Parental counseling and support critical. Long-term survivors have profound intellectual disability and require comprehensive care.

• Genetic counseling
• Carrier screening
• Prenatal diagnosis
• Preimplantation genetic diagnosis
• Family planning