Connect My Variant is a nonprofit organization that focuses on building communities for communication about genetic testing and hereditary disease prevention.

Conquer Chiari is a patient advocacy organization focused on raising awareness and providing resources for individuals affected by Chiari Malformation, a serious neurological disorder.

The Consortium of Multiple Sclerosis Centers focuses on advancing care and education for individuals affected by multiple sclerosis through various programs, advocacy, and professional engagement.

Contact is a charity that supports families with disabled children by providing information, advice, and emotional support, as well as organizing workshops and events.

Cook for Love provides low-protein recipes and cooking resources, primarily aimed at individuals with dietary restrictions related to certain health conditions.

The Cooley’s Anemia Foundation supports individuals affected by Thalassemia through education, research funding, and various patient support programs.

The Cornea Research Foundation of America conducts research to improve vision treatments and serves as a resource for individuals seeking help with vision problems.

The Corneal Dystrophy Foundation provides support and information for individuals and families affected by corneal dystrophies, including resources, support groups, and educational materials.

The CdLS Foundation provides support services and resources for individuals affected by Cornelia de Lange Syndrome (CdLS) and aims to educate families and professionals about the condition.

The Cortical Foundation is dedicated to educating, advocating for, and supporting individuals affected by cortical malformations, which are rare developmental abnormalities of the brain.

The Costello Syndrome Family Network (CSFN) is a nonprofit organization dedicated to supporting individuals with Costello syndrome and their families by promoting awareness, research, and providing resources for better management of the condition.

The Council for Exceptional Children (CEC) is dedicated to supporting special education professionals and enhancing the education of students with exceptionalities through resources, events, and advocacy.

Courage Kenny Rehabilitation Institute, part of Allina Health, provides a wide range of inpatient and outpatient rehabilitation services for individuals with injuries and disabilities, focusing on maximizing health and independence.

Cranio Care Bears provides support and encouragement to families of children facing surgery for craniosynostosis through care packages that help relieve stress during this serious procedure.

The CJD Foundation supports families affected by prion diseases, providing resources, education, and advocacy while funding research and organizing community events.

The Cri du Chat Support Group has transitioned its services to the charity Unique, which supports families affected by Cri du Chat Syndrome and other rare chromosome and gene disorders.

Crisis Connections is a nonprofit organization that provides 24/7 crisis support and resources for individuals in need, including suicide prevention education and community outreach services.

Cruse Bereavement Support provides support and training for individuals dealing with grief and bereavement, offering local services and a helpline across England, Wales, and Northern Ireland.

CSNK2A1 Foundation is dedicated to finding a cure for Okur-Chung Neurodevelopmental Syndrome and providing support for affected individuals and their families.

Cure 4 The Kids Foundation is dedicated to advancing the treatment and prevention of childhood cancer and rare diseases through clinical expertise, research, and compassionate care for children and their families.