What Is Tyrosinemia? Hereditary tyrosinemia refers to a group of inherited metabolic disorders caused by enzymatic defects in the tyrosine degradation pathway. Based on distinct deficient enzymes, three major clinical subtypes are recognized: Type I (HT1), Type II (TAT deficiency)…
What Is Retinoblastoma? Retinoblastoma (RB) is the most common intraocular malignant tumor in children. Its pathogenesis is primarily triggered by biallic inactivation of the RB1 tumor suppressor gene; a small subset of RB cases with wild-type RB1 are driven by…
What Is Neuroblastoma? Neuroblastoma (NB) is the most common extracranial solid tumor in children, accounting for 8%–10% of all pediatric malignancies, and is known as the “king of childhood tumors” due to its highly heterogeneous clinical manifestations. Based on molecular…
What Is Fanconi Anemia? Fanconi Anemia (FA) is a rare inherited bone marrow failure syndrome. Its primary inheritance mode is autosomal recessive, while approximately 2% of cases show X-linked recessive transmission. The disease is characterized by congenital developmental abnormalities, progressive…
What Is Congenital Adrenal Hyperplasia? Congenital Adrenal Hyperplasia (CAH) is an autosomal recessive hereditary disorder caused by deficient key enzymes in adrenal cortical hormone biosynthesis. Its core pathological feature is impaired cortisol synthesis. Reduced cortisol releases negative feedback suppression of…
What Is Retinitis Pigmentosa? Retinitis Pigmentosa (RP) is a highly genetically heterogeneous degenerative retinal disorder pathologically characterized progressive photoreceptor loss and retinal pigment epithelium (RPE) atrophy. Core clinical manifestations include nyctalopia, gradual peripheral visual field constriction, and progressive central vision…
What Is Niemann-Pick Disease? Niemann-Pick Disease (NPD) is an autosomal recessive lysosomal storage disorder, also referred to as sphingomyelin-cholesterol lipidosis. Based on pathogenic mechanisms and clinical manifestations, NPD is divided into two major subgroups: Type A/B and Type C. Type…
What Is Hemophilia? Hemophilia is an X-linked recessive hemorrhagic disorder triggered by pathogenic variants in the F8 gene (chromosomal locus Xq28) or F9 gene (Xq27). Such mutations impair synthesis and function of coagulation factor VIII (FVIII) or factor IX (FIX),…
What Is Methylmalonic Acidemia? Methylmalonic Acidemia (MMA) is an autosomal recessive organic acid metabolic disorder with onset in the neonatal or early infantile period. Its clinical course is insidious yet rapidly progressive, featuring multi-system injuries. Typical neurological manifestations include intellectual…
What Is Tuberous Sclerosis Complex? Tuberous Sclerosis Complex (TSC) is a rare autosomal dominant multisystem genetic disorder that primarily damages the brain, skin, kidneys, heart, lungs and other organs. Its hallmark clinical manifestations include cortical tubers, recurrent epilepsy, intellectual disability,…
