What is Mucopolysaccharidosis Type II (MPS2)?
Mucopolysaccharidosis Type 2 is a progressive genetic disorder. Children born with the syndrome are usually healthy at birth, and symptoms usually develop from the age of 2 years or slightly older. The disease has two types: severe and mild, with varying degrees of symptoms between the types.
The disorder is rare and occurs in anywhere between 1 in 100-170,00 live births. Due to the way in which it is inherited, it affects mainly males.
Syndrome Synonyms:
Hunter Syndrome; IDS Deficiency; Iduronate 2-sulfatase Deficiency; MPS II; MPSII Mucopolysaccharidosis type II; SIDS Deficiency; Sulfoiduronate Sulfatase Deficiency
What gene change causes Mucopolysaccharidosis Type II (MPS2)?
The syndrome is a lysosomal storage disease affecting the body’s ability to break down the large sugar molecules known as glycosaminoglycans. The buildup of these molecules in the body tissue triggers the symptoms of the syndrome. In this specific type, the gene affected is IDS.
The disease is an X-linked recessive disorder and affects mainly males. Syndromes inherited in an X-linked recessive pattern generally only affect males. Males only have one X chromosome, and so one copy of a gene mutation on it causes the syndrome. Females, with two X chromosomes, only one of which will be mutated, are not likely to be affected.
What are the main symptoms of Mucopolysaccharidosis Type II (MPS2)?
Symptoms of the syndrome usually present post-infancy and from the age of 2-4 years. Children who appear to be developing typically will start to present with various symptoms depending on whether they have the mild or severe type of the disease. Intellectual disability tends only to affect those individuals with a severe type of condition.
The syndrome’s physical features include a large head, thick skin and lips, a broad nose, flared nostrils, a protruding tongue, and a deep, hoarse voice. Hydrocephalus, or fluid on the brain, is another major symptom, as is a distended stomach due to the enlargement of internal organs and abdominal hernia. Individuals tend to experience a slowdown in their growth from the age of five years.
Other possible health conditions related to the syndrome include skeletal abnormalities related to a thickening of the bones, an enlargement of internal body organs including the spleen and liver, hernias, frequent respiratory infections, carpal tunnel syndrome, and heart valve abnormalities.
Possible clinical traits/features:
Abnormality of immune system physiology, Inguinal hernia, Intellectual disability, profound, Intestinal pseudo-obstruction, Laryngomalacia, Macroglossia, Pectus excavatum, Mandibular prognathia, Mild short stature, Neurodegeneration, Malabsorption, Short stature, Opacification of the corneal stroma, Hepatomegaly, Hearing impairment, Heparan sulfate excretion in urine, Depressed nasal bridge, Kyphosis, Hypertrichosis, Hydrocephalus, Hoarse voice, Cognitive impairment, Severe short stature, Dysostosis multiplex, Coarse facial features, Congestive heart failure, Depressed nasal ridge, Dermatan sulfate excretion in urine, Thickened skin, Dolichocephaly, Diarrhea, Flexion contracture, Split hand, Delayed eruption of teeth, Limitation of joint mobility, Papilledema, Pes cavus, Recurrent otitis media, Thin vermilion border, Short neck, Obstructive sleep apnea, Optic atrophy, Widely spaced teeth, Seizure, X-linked recessive inheritance, Umbilical hernia, Ptosis, Tracheal stenosis, Tracheobronchomalacia, Thick lower lip.
How is it diagnosed?
To find out if someone has a diagnosis of Mucopolysaccharidosis Type II, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
