is a harmless milk-filled breast cyst that can develop during breastfeeding.

causes digestive symptoms after dairy, due to lactase enzyme deficiency.

is a rare epilepsy causing seizures, muscle jerks (myoclonus), and progressive decline.

is a genetic muscle disorder causing early weakness in feet and hands.

is a rare genetic disorder affecting the kidneys, eyes, and development.

is a rare genetic condition causing developmental and speech delays.

is a rare immune disorder that causes very low antibody levels.

is a rare autoimmune disorder causing muscle weakness and fatigue.

is a rare autoimmune disorder causing muscle weakness and easy fatigue.

is a rare inherited skin disorder causing widespread dry, plate-like scaling.

is a genetic muscle disease causing weakness, hypotonia, and delayed development.

is a rare genetic muscle disease causing weakness in hips and shoulders.

is a genetic muscle disorder causing weakness, low tone, delayed milestones.

is a group of genetic disorders affecting muscles, heart, fat, and aging.

is a rare genetic disorder causing abnormal fat loss and other problems.

is a genetic disorder affecting muscles, nerves, and sometimes the heart.

is a group of rare genetic disorders that can cause early aging.

is a genetic disorder affecting muscles, heart, and sometimes movement.

is a rare childhood disorder causing language loss (aphasia) and seizures.

is a rare genetic condition causing very short limbs and short stature.

is a rare disorder where immune cells build up and damage tissues.

is a rare, aggressive cancer of immune cells called Langerhans cells.

is a rare disorder where excess immune cells can damage tissues.

affects how a person understands, uses, or communicates with language.