The International Rett Syndrome Foundation (IRSF) is dedicated to supporting families affected by Rett syndrome through research funding, advocacy, and community resources.

The International Sacral Agenesis/Caudal Regression Association (iSACRA) supports individuals with sacral agenesis/caudal regression syndrome by providing a community for connection, information, and resources.

ISMRD is a not-for-profit organization advocating for families and patients affected by Glycoprotein Storage Diseases, providing resources and support for early detection and effective treatment.

The Minneapolis Heart Institute Foundation is dedicated to improving cardiovascular health through innovative research and education, focusing on heart and vascular diseases.

L'Institut de Génétique Humaine conducts fundamental research in genetics, focusing on immunology and oncology, and aims to translate this research into practical applications in pathology.

ITSAN is a patient advocacy organization that provides resources and support for individuals suffering from Topical Steroid Withdrawal (TSW), helping them navigate their condition and connect with a supportive community.

The International WAGR Syndrome Association supports individuals and families affected by WAGR syndrome, a rare genetic disorder, by providing awareness, research, and resources.

The International Waldenstrom’s Macroglobulinemia Foundation supports individuals affected by Waldenstrom's macroglobulinemia by providing resources, education, and community support.

The Interstitial Cystitis Association is a nonprofit organization dedicated to ensuring efficient diagnosis and optimal care for individuals affected by interstitial cystitis/bladder pain syndrome (IC/BPS) through advocacy, education, and community support.

The Intestinal Malrotation Foundation provides community support, awareness, advocacy, and education for individuals affected by intestinal malrotation and its complications.

This organization provides educational resources and support for patients undergoing intestinal rehabilitation and transplantation, focusing on conditions like short bowel syndrome.

The Intracranial Hypertension Research Foundation advocates for and supports medical research for chronic intracranial hypertension (IH), providing education and assistance to affected individuals and their families.

Chronic Pain Ireland is a national charity that supports, educates, and advocates for individuals living with chronic pain across Ireland, providing resources, workshops, and a helpline for support.

The Irish Haemophilia Society represents people living with haemophilia, von Willebrands, and other inherited bleeding disorders, providing support, education, and resources to help manage these conditions.

The Irish Heart Foundation is dedicated to providing care and support for heart and stroke patients and their families in Ireland, offering resources, guidance, and advocacy programs.

Iron Disorders Institute is a national organization focused on providing information and support for individuals with iron disorders, including hemochromatosis and iron deficiency.

This organization provides support and information for individuals suffering from Irritable Bowel Syndrome (IBS), focusing on awareness, symptoms, and management strategies.

The Jack Bear Foundation is dedicated to raising awareness and funding research for Spinocerebellar Ataxia Recessive Type 15, a rare degenerative genetic disease.

Jack's Tomorrow is dedicated to funding research for PURA Syndrome, aiming to develop treatments and ultimately a cure for the disease.