Immune Deficiency Foundation (Immune Deficiency Disorders, Severe Combined Immunodeficiency Syndrome)

Incontinentia Pigmenti International Foundation (Incontinentia Pigmenti)

International Children's Anophthalamia Network (Anophthamia, Microphthalmia)

International Costello Syndrome Support Group (Costello Syndrome)

International Dyslexia Association (Dyslexia)

International Fibrodysplasia Ossificans Progressiva (FOP) Association (Fibrodysplasis Ossificans Progressiva)

International Joseph Diseases Foundation Inc. (Joseph's Disease)

International Lesch-Nyhan Disease Association (Lesch-Nyhan Disease)

International Organization for Glutaric Aciduria (Glutaric Aciduria, Type I)

International Progeria Registry (Progeria)

International Society for Mannosidosis & Related Diseases, Inc. (Alpha Mannosidosis, Aspartylglucosaminuria, Beta Mannosidosis, Fucosidosis, Galactosialidosis, Sialidosis, Schindler Disease)

International Tremor Foundation (Tremors)

Intersex Society of North America (Ambiguous Genitalia, Hermaphroditism)

In the Blink of an Eye (Visual Impairment, Ocular Histoplasmosis)

Iron Overload Diseases Association Inc. (Hemochromatosis, Iron Overload, Porphyria, Thalassemia )

Isodicentric Duplication Exchange Advocacy and Support (IDEAS) (Chromosome 15 Disorders)