Metachromatic leukodystrophy, or MLD, is a rare lysosomal storage disorder that results from mutations in the ARSA gene, which codes for arylsulfatase A – an enzyme that normally breaks down a fat called sulfatide. Without this enzyme, sulfatide accumulates in neurons and myelin-producing cells like Schwann cells and oligodendrocytes, resulting… Continue Reading Metachromatic leukodystrophy – causes, symptoms, diagnosis, treatment, pathology

Primary mitochondrial myopathy is a rare genetic disorder that occurs when there are mutated mitochondria in muscle cells, especially skeletal muscle cells. These mitochondria are unable to generate adenosine triphosphate, or ATP, which is a form of energy used by our cells. As a result, muscle cells, which require a… Continue Reading Primary mitochondrial myopathy – causes, symptoms, diagnosis, treatment, pathology

With Fragile X syndrome, sometimes just called Fragile X, the “X” refers to the X chromosome, where the disease gene is located. The “fragile” refers to the fact that under a microscope, the X chromosome looks fragile or broken at the site of the mutation. That’s because the chromatin which… Continue Reading Fragile X Syndrome – causes, symptoms, diagnosis, treatment, pathology

Friedreich’s ataxia is a disorder where there’s a buildup of iron that damages various organ systems – in particular, the nervous system gets damaged which causes ataxia, which is when the muscles don’t move in a coordinated way. The disorder also affects some internal organs like the heart and pancreas.… Continue Reading Friedreich’s ataxia – causes, symptoms, diagnosis, treatment, pathology

Learning medicine is hard work! Osmosis makes it easy. It takes your lectures and notes to create a personalized study plan with exclusive videos, practice questions and flashcards, and so much more. Try it free today! With X-linked agammaglobulinemia, or XLA for short, gamma globulin is another name for immunoglobulin,… Continue Reading X-linked agammaglobulinemia- causes, symptoms, diagnosis, treatment, pathology

Protein C and S are two anticoagulation proteins that inactivate coagulation factors Va and VIIIa in the coagulation cascade. This means they act like brakes on coagulation, limiting clot formation and preventing clots from growing too big. So when either of these proteins is deficient, it leads to a hypercoagulable… Continue Reading Protein C and S deficiency – causes, symptoms, diagnosis, treatment, pathology

With adrenoleukodystrophy, sometimes called ALD, adreno- refers to the adrenal glands, while -leuko-, means white, and -dystrophy refers to tissue degradation. So, adrenoleukodystrophy is a rare genetic condition, caused by a mutation in the ABCD1 gene, located in the X-chromosome, that leads to the progressive loss of white matter in… Continue Reading Adrenoleukodystrophy – causes, symptoms, diagnosis, treatment, pathology

Posttransplant lymphoproliferative disorders, or PTLDs, are uncontrolled growths of cells called lymphocytes that may occur in transplant recipients after receiving a solid organ, such as a kidney or a lung, or stem cells. Transplant recipients require medications to suppress their immune systems which may contribute to the development of a… Continue Reading Posttransplant lymphoproliferative disorders – causes, symptoms, diagnosis, treatment, pathology

Guillain-Barré syndrome is named after two neurologists- Georges Guillain and Jean Barré, and it’s a demyelinating disease of the peripheral nervous system, which includes all of the neurons that extend beyond the brain and the spinal cord. Guillain-Barré, or GBS for short, is also called acute inflammatory demyelinating polyneuropathy. Neurons… Continue Reading Guillain-Barre Syndrome – causes, symptoms, diagnosis, treatment, pathology

Niemann-Pick disease type C, or NPC, is a rare genetically inherited condition caused by mutations in either the NPC1 or NPC2 genes. These mutations impair intracellular transport of cholesterol and other molecules, which causes progressive neurologic and developmental problems. Now, cholesterol reaches the cells packed in lipoproteins, which bind to… Continue Reading Niemann-Pick disease Type C – causes, symptoms, diagnosis, treatment, pathology