Focal segmental glomerulosclerosis (FSGS) is a serious kidney condition that develops when scar tissue forms in the tiny filtering units of your kidneys, making it difficult for them to remove waste from your blood and potentially leading to kidney failure.

Fragile X syndrome is the most common inherited cause of intellectual disability and a leading genetic cause of autism. It affects how the brain develops and can impact learning, behavior, and physical features throughout a person’s life.

Friedreich’s ataxia is a rare inherited disorder that progressively damages the nervous system, affecting movement, balance, and coordination. While symptoms typically begin in childhood or adolescence, the disease’s progression varies greatly from person to person, and advances in care and treatment continue to improve outcomes for those living with this condition.

Gastrointestinal stromal tumours are rare cancerous growths that develop in the digestive system, most commonly in the stomach or small intestine, and can range from very small to large masses that cause serious symptoms.

Gaucher’s disease type I is the most common form of this rare genetic disorder, affecting approximately 95% of cases in western countries and being the most prevalent Jewish genetic disorder. While it causes symptoms ranging from enlarged organs and bone pain to bleeding problems, effective treatments are available that can help patients live full, active lives well into old age.

Gaucher’s disease type III is a rare inherited condition where the body cannot properly break down fatty substances, leading to progressive problems affecting the brain, bones, and major organs throughout life.

Membranoproliferative glomerulonephritis is an uncommon kidney disorder that involves inflammation and damage to the tiny filters in your kidneys, potentially leading to serious kidney problems and requiring ongoing medical care.

Membranous glomerulonephritis is a kidney disease where your immune system mistakenly attacks the tiny filters in your kidneys, causing protein to leak into your urine and potentially leading to serious complications if left untreated.

Rapidly progressive glomerulonephritis is a serious kidney condition that can damage your kidneys in just days to weeks. Without early diagnosis and treatment, it can lead to permanent kidney failure.

Glycogen storage disease type I is a rare inherited disorder that prevents the body from properly breaking down stored sugar, causing severe low blood sugar and serious health complications if left untreated.

Glycogen storage disease type II is a rare inherited condition that prevents the body from breaking down glycogen properly, leading to its buildup in cells and causing progressive muscle weakness, heart problems, and breathing difficulties that can be life-threatening without early treatment.

Glycogen storage disease type V is a rare inherited condition that affects how muscles use stored energy, causing fatigue, pain, and cramps during physical activity. While symptoms usually begin in childhood or young adulthood, many people aren’t diagnosed until decades later due to the condition often being misdiagnosed or overlooked.

Haemolytic uraemic syndrome is a serious condition that damages small blood vessels, most commonly affecting the kidneys and often occurring after bacterial infection, particularly in young children.

Haemophagocytic lymphohistiocytosis is a rare and life-threatening condition where the immune system attacks the body’s own tissues instead of defending it against disease. Without prompt diagnosis and treatment, this severe inflammatory syndrome can lead to organ failure and death within months, but early intervention and proper care can save lives.

Haemophilia is a rare inherited blood disorder in which blood does not clot properly, causing prolonged bleeding from injuries and sometimes internal bleeding that can damage joints and organs.

Haemophilia A with anti factor VIII represents one of the most challenging complications in treating this inherited bleeding disorder. When the body creates antibodies against the very treatment meant to help, managing bleeding episodes becomes significantly more difficult.

Haemophilia A is a hereditary bleeding disorder where blood does not clot properly due to a lack of clotting factor VIII. With proper treatment and care, people with this condition can lead full and active lives.

When the body’s immune system creates antibodies against the very treatment meant to help, managing haemophilia B becomes significantly more challenging.

Haemophilia B, also known as Christmas disease, is an inherited bleeding disorder caused by a deficiency in clotting factor IX. While it predominantly affects males due to its X-linked inheritance pattern, effective treatment allows most people with this condition to lead normal, active lives.

Hairy cell leukaemia is a rare type of cancer that grows slowly in the blood and bone marrow, named after the unusual “hairy” appearance of the affected cells when viewed under a microscope.

Hairy cell leukaemia is a rare type of blood cancer that often comes back after treatment, but patients can achieve further periods of remission with repeated therapy.

Hepatic angiosarcoma is a rare but highly aggressive cancer that develops in the blood vessels of the liver. Though it accounts for less than 2% of all liver cancers, it is the third most common primary liver cancer and the most common malignant tumor arising from the liver’s blood vessels in adults.

Hepatoblastoma is a very rare type of liver cancer that primarily affects babies and young children, most commonly before their third birthday. While the diagnosis can be frightening for families, advances in treatment combining chemotherapy and surgery have dramatically improved outcomes, with many children achieving complete recovery.

Hereditary angioedema (HAE) is a rare genetic condition that causes sudden, severe swelling in different parts of the body. Though unpredictable and potentially life-threatening, advances in treatment now offer hope for people living with this challenging disorder.

Hereditary ataxia represents a complex group of genetic disorders that cause progressive problems with balance, coordination, and movement, affecting thousands of people and their families around the world.

Hereditary hypophosphataemic rickets is a group of genetic disorders that prevent the kidneys from properly handling phosphate, a mineral essential for building strong bones and teeth. When phosphate levels drop too low, children develop bone abnormalities like bowed legs, while adults experience bone pain and weakness.

Hereditary motor and sensory neuropathy is a group of inherited conditions that progressively damage the nerves connecting your brain and spinal cord to the rest of your body, causing muscle weakness, sensory changes, and foot problems that can affect your daily life.

Hereditary neuropathic amyloidosis is a rare inherited disease where abnormal proteins build up in the body’s nerves and organs, slowly causing damage that can affect sensation, movement, and many bodily functions.

Hereditary optic atrophy is a group of inherited disorders that damage the optic nerve, causing progressive vision loss that typically begins in childhood or adolescence and affects both eyes.

Hypereosinophilic syndrome is a rare group of blood disorders caused by an excess of white blood cells called eosinophils, which can damage organs throughout the body. Without treatment, this condition can be life-threatening, but with prompt diagnosis and care, more than 80% of people are alive five years after diagnosis.

Hyperoxaluria occurs when there is too much oxalate in the urine, leading to kidney stones and potentially serious kidney damage that can affect long-term health.

Idiopathic inflammatory myopathy is a group of rare autoimmune diseases that cause chronic muscle inflammation and weakness, often affecting daily activities like climbing stairs or lifting objects, while also potentially impacting other organs including the skin, lungs, and heart.

Idiopathic pulmonary fibrosis is a serious lung disease where tissue surrounding the air sacs becomes thick, stiff, and scarred for reasons that remain unknown. This progressive condition makes breathing increasingly difficult over time, affecting mostly people in their 60s and 70s.

IgA nephropathy is a kidney disease where a specific protein builds up in the kidneys, causing inflammation and damage over time. While it often progresses slowly and may go unnoticed for years, it is one of the most common kidney diseases worldwide and can eventually lead to kidney failure if not properly managed.

Congenital immunodeficiency disorders are a group of inherited conditions where the immune system doesn’t work properly from birth, making it harder for the body to fight off infections and other health challenges.

Inclusion body myositis is a slowly progressive muscle disease that most commonly affects people over 45, causing gradual weakness in the limbs and fingers. While there is currently no cure, understanding this condition and staying active can help maintain quality of life.

Indolent systemic mastocytosis is the most common form of a rare chronic disorder where abnormal mast cells build up in the body, mainly in the bone marrow and skin, causing symptoms that can range from mild to severely debilitating.

Isodicentric chromosome 15 syndrome is a rare genetic condition caused by extra genetic material from chromosome 15, leading to challenges with development, learning, and sometimes seizures.

KBG syndrome is a rare genetic disorder that affects multiple body systems, characterized by distinctive facial features, unusually large front teeth, short stature, skeletal abnormalities, and developmental delays. Named after the initials of the first families diagnosed, this condition shows wide variation in how it affects individuals, even within the same family.

Kearns-Sayre syndrome is a rare condition that mainly affects the eyes, heart, and muscles, caused by problems in the tiny energy-producing structures within body cells. Most people develop symptoms before age 20, and while there is no cure, early diagnosis and supportive care can help manage the condition and improve quality of life.

Krabbe’s disease is a rare, inherited condition that progressively damages the protective covering of nerve cells in the brain and nervous system, leading to severe neurological problems that worsen over time and usually result in death, most commonly affecting babies in their first year of life.

Langerhans cell sarcoma is a rare and aggressive cancer that develops from specialized immune cells called Langerhans cells, which normally help protect the body from infection. Unlike the related but less serious condition called Langerhans cell histiocytosis, this disease shows clearly malignant features and often affects multiple parts of the body.

Langerhans’ cell histiocytosis is a rare disorder where a specific type of immune cell builds up in the body, potentially causing tissue damage and tumors in various organs. While it primarily affects children, the disease can occur at any age and ranges from mild conditions that resolve on their own to severe forms requiring intensive treatment.

Leiomyosarcoma is a rare and aggressive cancer that develops in smooth muscles found in various organs throughout the body. While it can grow quickly and spread to other tissues, early detection and treatment offer the possibility of recovery.

Metastatic leiomyosarcoma is an aggressive cancer that has spread from its original site to other parts of the body. While this advanced stage presents serious challenges, understanding the disease, treatment options, and survival factors can help patients and their families navigate this difficult journey.

Recurrent leiomyosarcoma is when this aggressive cancer returns after initial treatment, presenting challenges for patients and their medical teams. Understanding recurrence patterns, treatment options, and factors that influence survival can help patients navigate this difficult journey.

Lennox-Gastaut syndrome is a severe form of childhood epilepsy that causes multiple types of seizures, developmental delays, and lasting disabilities. While there is no cure, various treatments can help control symptoms and improve quality of life.

Loeys-Dietz syndrome is a genetic condition that affects the body’s connective tissue, causing problems with blood vessels, bones, skin, and other body parts. This disorder can lead to serious complications, especially in the heart and blood vessels, but with proper diagnosis and care, many people with the condition can live full lives.

Lymphangioma is a rare, noncancerous fluid-filled cyst that typically appears in newborns and young children, most commonly on the head or neck. These growths develop when the lymphatic system doesn’t form properly during fetal development, causing fluid to collect under the skin.

Lymphangiosarcoma is a rare and aggressive cancer that develops in people with long-standing swelling of the lymph nodes, most commonly affecting the arms. This serious condition requires prompt diagnosis and treatment, though its rarity means it is less well-known than many other cancers.

Lymphatic malformations are clusters of abnormal lymph vessels that form fluid-filled cysts under the skin or within body tissues. These noncancerous growths develop before birth and most commonly appear on the head and neck, though they can occur anywhere in the body except the brain.

Lysosomal storage disorders are rare genetic conditions where the body’s cells cannot properly break down fats, sugars, and other substances, leading to a toxic buildup that can damage organs throughout the body.

Malignant fibrous histiocytoma is a rare and aggressive type of cancer that affects soft tissues or bones, most commonly appearing as a painless mass in the arms or legs of older adults, though it can occur in children and throughout the body.

Mantle cell lymphoma is a rare type of blood cancer that develops when certain white blood cells grow out of control. While it cannot be cured, treatment can help manage symptoms and extend periods when the disease is not active.

Mantle cell lymphoma can stop responding to treatment or return after remission, presenting one of the most difficult challenges in cancer care today.

Mantle cell lymphoma stage II affects two or more groups of lymph nodes on the same side of the diaphragm. This rare blood cancer develops when abnormal B cells grow out of control in the lymphatic system, typically requiring treatment with a combination of therapies.

Mantle cell lymphoma stage III is a rare and aggressive form of blood cancer that affects lymph nodes on both sides of the diaphragm. While the diagnosis can be challenging, understanding this condition and the available treatment options can help patients and their families navigate the journey ahead.

Mantle cell lymphoma stage IV represents the most advanced form of this rare blood cancer, where the disease has spread beyond the lymph nodes to other parts of the body. Understanding this diagnosis, its implications, and available treatment options can help patients and their families navigate this challenging journey.

Marfan syndrome is a genetic condition that weakens the body’s connective tissue, affecting the heart, blood vessels, eyes, bones, and other organs. With proper care and monitoring, people with this condition can live long and productive lives.

Marginal zone lymphoma is a slow-growing type of cancer that affects the body’s immune system, typically diagnosed in people over age 60, and can often be treated successfully with various approaches depending on where the disease develops.