When a certain gene causes disease due to mutation it is known as Single gene disorder. As a consequence, the genes which code for protein is either altered or missing.

• A defective gene from one or in some cases both parents is carried from parent to child.
• Child at birth is born with a disorder
• Most genetic disorders are asymptomatic at birth
• The disease condition progresses as the child ages
• High morbidity has been observed especially in Single gene disorders

Most common diseases associated with Single gene disorder

Cystic fibrosis, Sickle cell disease, Fragile X syndrome, Muscular Dystrophy & Huntington Disease.