Pediatric amastia is the absence of the entire breast — including the breast tissue, nipple and areola.
Amastia is a rare, congenital (present at birth) condition in which a child’s breast tissue doesn’t develop. Amastia can affect one (unilateral) or both (bilateral) breasts. Children with bilateral amastia often have other birth defects.
Amastia can be caused by several genetic conditions that affect a child’s DNA and development, including:
Hypohidrotic ectodermal dysplasia – a genetic condition that can also impact the development or function of the hair, nails, sweat glands and teeth.
Poland syndrome (sequence) – a rare birth defect that causes underdevelopment or absence of the chest muscle.
Yunis-Varon syndrome – a genetic condition that also affects the nervous system, skeletal system and ectodermal tissues (hair and teeth).
The main sign of amastia is a flat chest with no breast tissue or nipples. Additional symptoms may develop if the child has a genetic condition, which will be specific to that disease.