Definition & EpidemiologyOlmsted syndrome (OS; OMIM #164900) is an extremely rare, non-neoplastic congenital disorder characterized by progressive, symmetrical, mutilating palmoplantar keratoderma (PPK) with periorificial hyperkeratotic lesions. First described in 1928…
1. Definition and Pathophysiology Purple Urine Bag Syndrome (PUBS) is a rare, clinically benign but visually striking complication of long-term indwelling urinary catheterization, characterized by the appearance of purple- to…
Overview of Eczema ‘Eczema’ is a very commonly known skin condition. It is a Greek word. The meaning of eczema is ‘to boil’. Many people use the word eczema to…
1. Genetic Basis and Pathophysiology Menkes disease (MD; OMIM #309400) is an X-linked recessive disorder caused by pathogenic variants in the ATP7A gene (chromosome Xq21.1), which encodes a P-type ATPase…
Epidemiology and Classification 48,XXYY syndrome is a rare sex chromosome aneuploidy affecting approximately 1 in 18,000–50,000 male births. It falls under the broader spectrum of Klinefelter variant syndromes, which includes…
Clinical Overview Osteogenesis Imperfecta (OI) is a heterogeneous group of connective tissue disorders characterized by bone fragility and varying degrees of skeletal, ocular, and auditory manifestations. While classically defined by…
Introduction Huntington’s Disease (HD) is a devastating, autosomal dominant neurodegenerative disorder caused by a pathogenic CAG trinucleotide repeat expansion in the HTT gene on chromosome 4p16.3. This mutation results in…
IntroductionOsteoporosis is a systemic skeletal disorder characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and susceptibility to fracture (Cosman et al., Endocrine…
Prepared for the Practicing Rheumatologist / Pediatrician Definition & Epidemiology Juvenile Idiopathic Arthritis (JIA) is a heterogeneous group of chronic arthritides of unknown etiology onset before age 16, persisting ≥6…
Treacher Collins syndrome (TCS), also known as Mandibulofacial Dysostosis (OMIM #154500) or historically as Franceschetti-Zwahlen-Klein syndrome, is a rare autosomal dominant craniofacial disorder characterized by bilateral symmetric anomalies of the…
Overview & Definition Peritoneal mesothelioma (PM) is a rare, aggressive malignancy arising from the mesothelial cells lining the peritoneum—the serous membrane encapsulating abdominal organs. accounting for 10–30% of all malignant…
1. Background & Epidemiology Crystalline silica (SiO₂), predominantly in the forms of quartz, tridymite, and * cristobalite*, is a ubiquitous mineral in the Earth’s crust and a key component of…
1. Definition & Pathogenesis Barrett’s esophagus (BE) is a premalignant condition characterized by the metaplastic replacement of the normal stratified squamous epithelium of the distal esophagus with specialized intestinal metaplasia…
Epidemiology & Pathogenesis Medullary thyroid carcinoma (MTC) accounts for 3–5% of all thyroid malignancies in the United States, with an annual incidence of ~0.5 cases per 100,000 persons. It arises…
Epidemiology and Pathobiology Urothelial carcinoma (UC), formerly termed transitional cell carcinoma (TCC), accounts for >90% of primary bladder malignancies and remains the fifth most common cancer in the United States…
