Nearly half of individuals with SPS have a family member with colorectal cancer. Most individuals (37–70%) with SPS fulfill criterion 3 of the 2010 criteria (now criteria 2 from the 2019 classification). Of the remaining individuals with SPS, roughly half meet only criterion 1 and half meet both criteria 1 and 3 (2010 classification). Among individuals undergoing colonoscopy for the evaluation of an abnormal fecal occult blood test, the prevalence of SPS ranges from 0.34 to 0.66%. The overall prevalence of SPS is 0.03–0.5%. The prevalence of SPS is between 1 in 127 and 1 in 242 among individuals undergoing colonoscopy. SPS is associated with tobacco use. Aside from colorectal cancer, the risk of others cancers is not increased in people with SPS. Aspirin and nonsteroidal anti-inflammatory drug (NSAIDs) may be associated with a lower risk of SPS. SPS is the most common polyposis syndrome affecting the colon.There is no clear association of SPS with any cancers other than colorectal cancer. However, there is mixed evidence regarding a possible association with SPS and pancreatic cancer. Individuals with a history of lymphoma have a higher risk of developing sessile serrated polyposis syndrome. == References ==
Zellweger syndrome is a rare congenital disorder characterized by the reduction or absence of functional peroxisomes in the cells of an individual. It is one of a family of disorders called Zellweger spectrum disorders which are leukodystrophies. Zellweger syndrome is named after Hans Zellweger (1909–1990), a Swiss-American pediatrician, a professor of pediatrics and genetics at the University of Iowa who researched this disorder. Signs and symptoms
Zellweger syndrome is one of three peroxisome biogenesis disorders which belong to the Zellweger spectrum of peroxisome biogenesis disorders (PBD-ZSD). The other two disorders are neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD). Although all have a similar molecular basis for disease, Zellweger syndrome is the most severe of these three disorders.Zellweger syndrome is associated with impaired neuronal migration, neuronal positioning, and brain development. In addition, individuals with Zellweger syndrome can show a reduction in central nervous system (CNS) myelin (particularly cerebral), which is referred to as hypomyelination. Myelin is critical for normal CNS functions, and in this regard, serves to insulate nerve fibers in the brain. Patients can also show postdevelopmental sensorineuronal degeneration that leads to a progressive loss of hearing and vision.Zellweger syndrome can also affect the function of many other organ systems. Patients can show craniofacial abnormalities (such as a high forehead, hypoplastic supraorbital ridges, epicanthal folds, midface hypoplasia, and a large fontanel), hepatomegaly (enlarged liver), chondrodysplasia punctata (punctate calcification of the cartilage in specific regions of the body), eye abnormalities, and renal cysts.