Explanation:

- Down Syndrome: This is a genetic disorder caused by the presence of an extra chromosome 21. It is an inherited genetic condition.

- Cystic Fibrosis: This is a hereditary disease caused by mutations in the CFTR gene, leading to thick mucus in the lungs and digestive system.

- Malaria: This is an infectious disease caused by Plasmodium parasites transmitted through mosquito bites. It is not inherited or passed down genetically.

- Muscular Dystrophy: This is a group of genetic disorders characterized by muscle weakness and degeneration. It is inherited.