What is Neuromyelitis Optica Spectrum Disorder? Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare autoimmune disorder of the central nervous system characterized primarily by recurrent episodes of optic neuritis and longitudinally extensive transverse myelitis. These attacks often lead to severe vision loss, motor, and sensory dysfunction. According to recent studies, the prevalence of NMOSD is approximately 1.82 per 100,000 individuals. Prevalence is significantly higher in African and Asian populations compared to Caucasian populations, and females are affected much more frequently than males (approximately a 10:1 ratio).

What is Glycogen Storage Disease (Type I, II)? Glycogen Storage Disease (GSD) is a rare autosomal recessive inherited metabolic disorder caused by defects in enzymes involved in glycogen synthesis or degradation, leading to abnormal glycogen accumulation in organs such as the liver and muscles. At least 19 subtypes are known, with Type I (GSD Type I, hepatic form) and Type II (GSD Type II, Pompe disease) being the most common, accounting for approximately 40% of GSD cases combined. The incidence of GSD I is about 1 in 100,000 to 1 in 20,000, and GSD II is about 1 in 100,000 to 1 in 14,000, with slight variations among subtypes. GSD I is divided into two subtypes:

What is Mucopolysaccharidosis? Mucopolysaccharidosis (MPS) is a group of rare inherited disorders belonging to the lysosomal storage diseases. These conditions are associated with deficiencies of specific enzymes responsible for degrading glycosaminoglycans (GAGs), also known as acid mucopolysaccharides. MPS affects multiple systems throughout the body, with primary symptoms including skeletal deformities, growth retardation, hepatosplenomegaly, cardiac problems, respiratory disorders, and neurological impairment, significantly impacting patients' quality of life and life expectancy. The estimated incidence of MPS is approximately 1 in 25,000.

What is Marfan Syndrome? Marfan Syndrome (MFS) is an autosomal dominant inherited disorder of connective tissue affecting multiple systems, including the skeletal, ocular, and cardiovascular systems. Patients typically present with disproportionately long limbs (dolichostenomelia), scoliosis, ectopia lentis, severe myopia, and most critically, aortic root dilation and dissecting aneurysms. Aortic complications are the leading cause of mortality in Marfan Syndrome patients. The incidence is approximately 1 in 5,000 individuals, with about 75% of cases having a family history and 25% arising from spontaneous mutations.

What is Paroxysmal Nocturnal Hemoglobinuria? Paroxysmal Nocturnal Hemoglobinuria (PNH) is a rare acquired clonal disorder of hematopoietic stem cells. The classic clinical triad of PNH includes: ● Hemolytic Anemia: Characterized primarily by chronic intravascular hemolysis, often manifesting as dark, cola-colored urine (hemoglobinuria) upon waking. ● Bone Marrow Failure: Some patients present with concurrent aplastic anemia (AA) or myelodysplastic syndromes (MDS). ● Thrombosis: High incidence of venous thrombosis, potentially affecting critical sites such as hepatic, mesenteric, and cerebral veins, representing a leading cause of mortality in PNH patients. PNH patients most commonly succumb to thrombosis or progressive cytopenia. The estimated incidence is 1 to 5 cases per million individuals.