Mucopolysaccharidosis, Type Ii (MPS2)

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MedlinePlus Genetics: ⁴² Mucopolysaccharidosis type II (MPS II), also known as Hunter syndrome, is a condition that affects many different parts of the body and occurs almost exclusively in males. It is a progressively debilitating disorder; however, the rate of progression varies among affected individuals.At birth, individuals with MPS II do not display any features of the condition. Between ages 2 and 4, they develop full lips, large rounded cheeks, a broad nose, and an enlarged tongue (macroglossia). The vocal cords also enlarge, which results in a deep, hoarse voice. Narrowing of the airway causes frequent upper respiratory infections and short pauses in breathing during sleep (sleep apnea). As the disorder progresses, individuals need medical assistance to keep their airway open.Many other organs and tissues are affected in MPS II. Individuals with this disorder often have a large head (macrocephaly), a buildup of fluid in the brain (hydrocephalus), an enlarged liver and spleen (hepatosplenomegaly), and a soft out-pouching around the belly-button (umbilical hernia) or lower abdomen (inguinal hernia). People with MPS II usually have thick skin that is not very stretchy. Some affected individuals also have distinctive white skin growths that look like pebbles. Most people with this disorder develop hearing loss and have recurrent ear infections. Some individuals with MPS II develop problems with the light-sensitive tissue in the back of the eye (retina) and have reduced vision. Carpal tunnel syndrome commonly occurs in children with this disorder and is characterized by numbness, tingling, and weakness in the hand and fingers. Narrowing of the spinal canal (spinal stenosis) in the neck can compress and damage the spinal cord. The heart is also significantly affected by MPS II, and many individuals develop heart valve problems. Heart valve abnormalities can cause the heart to become enlarged (ventricular hypertrophy) and can eventually lead to heart failure.Children with MPS II grow steadily until about age 5, and then their growth slows and they develop short stature. Individuals with this condition have joint deformities (contractures) that significantly affect mobility. Most people with MPS II also have dysostosis multiplex, which refers to multiple skeletal abnormalities seen on x-ray. Dysostosis multiplex includes a generalized thickening of most long bones, particularly the ribs.There are two types of MPS II, called the severe and mild types. While both types affect many different organs and tissues as described above, people with severe MPS II also experience a decline in intellectual function and a more rapid disease progression. Individuals with the severe form begin to lose basic functional skills (developmentally regress) between the ages of 6 and 8. The life expectancy of these individuals is 10 to 20 years. Individuals with mild MPS II also have a shortened lifespan, but they typically live into adulthood and their intelligence is not affected. Heart disease and airway obstruction are major causes of death in people with both types of MPS II.

MalaCards based summary: Mucopolysaccharidosis, Type Ii, also known as hunter syndrome, is related to mucopolysaccharidosis with skin involvement and mucopolysaccharidoses, and has symptoms including diarrhea, seizures and hoarseness. An important gene associated with Mucopolysaccharidosis, Type Ii is IDS (Iduronate 2-Sulfatase), and among its related pathways/superpathways are Metabolism and Disease. The drugs Rituximab and Levoleucovorin have been mentioned in the context of this disorder. Affiliated tissues include spinal cord, skin and heart, and related phenotypes are macrocephaly and muscle weakness

Orphanet ⁵⁸ Mucopolysaccharidosis type 2, severe form: Mucopolysaccharidosis type 2 (MPS2, see this term), severe form (MPS2S), is associated with a massive accumulation of glycosaminoglycans and a wide variety of symptoms including a rapidly progressive cognitive decline; it is most often fatal in the second or third decade.

Mucopolysaccharidosis type 2, attenuated form: Mucopolysaccharidosis type 2, attenuated form (MPS2att), the less severe form of MPS2 (see this term), leads to a massive accumulation of glycosaminoglycans and a wide variety of symptoms including distinctive facies, short stature, cardiorespiratory and skeletal findings. It is differentiated from mucopolysaccharidosis type 2, severe form (see this term) by the absence of cognitive decline.

Mucopolysaccharidosis type 2: A lysosomal storage disease with multisystemic involvement leading to a massive accumulation of glycosaminoglycans and a wide variety of symptoms including distinctive coarse facial features, short stature, cardio-respiratory involvement and skeletal abnormalities. It manifests as a continuum varying from a severe form with neurodegeneration to an attenuated form without neuronal involvement.

GARD: ¹⁹ Mucopolysaccharidosis II (MPS II) is an inherited disorder of carbohydrate metabolism that occurs almost exclusively in males. It is characterized by distinctive facial features, a large head, hydrocephalus, enlargement of the liver and spleen (hepatosplenomegaly), umbilical or inguinal hernia, and hearing loss. Individuals with this condition may additionally have joint deformities and heart abnormalities involving the valves. MPS II is caused by genetic changes in the IDS gene and is inherited in an X-linked manner. There is a wide range in severity of symptoms present in individuals with MPS II. Previously, MPS II was classified as severe and attenuated based on severity. More recently, the terms slowly progressive and early progressive have been suggested. Individuals with the less severe type typically live into adulthood and intelligence is not affected.

UniProtKB/Swiss-Prot: ⁷³ An X-linked lysosomal storage disease characterized by intracellular accumulation of heparan sulfate and dermatan sulfate and their excretion in urine. Most children with MPS2 have a severe form with early somatic abnormalities including skeletal deformities, hepatosplenomegaly, and progressive cardiopulmonary deterioration. A prominent feature is neurological damage that presents as developmental delay and hyperactivity but progresses to intellectual disability and dementia. They die before 15 years of age, usually as a result of obstructive airway disease or cardiac failure. In contrast, those with a mild form of MPS2 may survive into adulthood, with attenuated somatic complications and often without intellectual disability.

OMIM®: ⁵⁷ Mucopolysaccharidosis II (MPS2) is a rare X-linked recessive disorder caused by deficiency of the lysosomal enzyme iduronate sulfatase, leading to progressive accumulation of glycosaminoglycans in nearly all cell types, tissues, and organs. Patients with MPS II excrete excessive amounts of chondroitin sulfate B (dermatan sulfate) and heparitin sulfate (heparan sulfate) in the urine (McKusick, 1972; Wraith et al., 2008). (309900) (Updated 08-Dec-2022)

Disease Ontology: ¹¹ A mucopolysaccharidosis characterized by a deficiency of the lysosomal enzyme iduronate sulfatase.

Wikipedia: ⁷⁵ Hunter syndrome, or mucopolysaccharidosis type II (MPS II), is a rare genetic disorder in which large... more...

Clinical features from OMIM®:

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