Question: What is (are) Mucopolysaccharidosis type I ?
Answer: Mucopolysaccharidosis I (MPS I) is a condition that affects many parts of the body. It is a progressively debilitating disorder; however, the rate of progression varies among affected individuals. MPS I is caused by mutations in the IDUA gene. These mutations lead to reduced levels or the complete lack of the IDUA enzyme. Without the proper amount of this enzyme, large sugar molecules called glycosaminoglycans (GAGs) accumulate within cells called lysosomes. This causes the lysosomes to increase in size, causing many different organs and tissues of the body to become enlarged. This leads to the medical problems seen in the condition. MPS I was once divided into three separate syndromes: Hurler syndrome, Hurler-Scheie syndrome, and Scheie syndrome, listed from most to least severe. Because no biochemical differences have been identified and the clinical findings overlap, the condition is now divided into two subtypes, severe MPS I and attenuated MPS I. People with severe MPS I typically have an earlier onset of symptoms, a decline in intellectual function, and a shorter lifespan. Although there is no cure for MPS I, bone marrow transplant and enzyme replacement therapy are treatment options that may help manage the symptoms of this condition.
Source: GARD

Question: What are the symptoms of Mucopolysaccharidosis type I ?
Answer: What are the signs and symptoms of Mucopolysaccharidosis type I? The signs and symptoms of MPS I are not present at birth, but they begin to appear during childhood. People with severe MPS I develop the features of this condition earlier than those with attenuated MPS I. The following list includes the most common signs and symptoms of MPS I. Enlarged head, lips, cheeks, tongue, and nose Enlarged vocal cords, resulting in a deep voice Frequent upper respiratory infections Sleep apnea Hydrocephalus Hepatosplenomegaly (enlarged liver and spleen) Umbilical hernia Inguinal hernia Hearing loss Recurrent ear infections Corneal clouding Carpal tunnel syndrome Narrowing of the spinal canal (spinal stenosis) Heart valve abnormalities, which can lead to heart failure Short stature Joint deformities (contractures) Dysostosis multiplex (generalized thickening of most long bones, particularly the ribs) The Human Phenotype Ontology provides the following list of signs and symptoms for Mucopolysaccharidosis type I. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormal form of the vertebral bodies 90% Abnormality of epiphysis morphology 90% Abnormality of the heart valves 90% Abnormality of the metaphyses 90% Abnormality of the tonsils 90% Abnormality of the voice 90% Coarse facial features 90% Hepatomegaly 90% Hernia 90% Hernia of the abdominal wall 90% Hypertrichosis 90% Limitation of joint mobility 90% Mucopolysacchariduria 90% Opacification of the corneal stroma 90% Otitis media 90% Scoliosis 90% Short stature 90% Sinusitis 90% Skeletal dysplasia 90% Splenomegaly 90% Abnormal nasal morphology 50% Abnormal pyramidal signs 50% Abnormality of the hip bone 50% Abnormality of the nasal alae 50% Apnea 50% Arthralgia 50% Cognitive impairment 50% Decreased nerve conduction velocity 50% Depressed nasal bridge 50% Developmental regression 50% Dolichocephaly 50% Enlarged thorax 50% Full cheeks 50% Gingival overgrowth 50% Glaucoma 50% Low anterior hairline 50% Macrocephaly 50% Malabsorption 50% Microdontia 50% Paresthesia 50% Recurrent respiratory infections 50% Retinopathy 50% Sensorineural hearing impairment 50% Spinal canal stenosis 50% Thick lower lip vermilion 50% Abnormal tendon morphology 7.5% Abnormality of the aortic valve 7.5% Aseptic necrosis 7.5% Congestive heart failure 7.5% Hemiplegia/hemiparesis 7.5% Hydrocephalus 7.5% Hypertrophic cardiomyopathy 7.5% Joint dislocation 7.5% Optic atrophy 7.5% Visual impairment 7.5% Aortic regurgitation - Autosomal recessive inheritance - Corneal opacity - Dysostosis multiplex - Hirsutism - Joint stiffness - Kyphosis - Mitral regurgitation - Obstructive sleep apnea - Pulmonary hypertension - Thick vermilion border - Tracheal stenosis - Umbilical hernia - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Mucopolysaccharidosis type I ?
Answer: What causes mucopolysaccharidosis I (MPS I)? Mutations in the IDUA gene cause MPS I. The IDUA gene provides instructions for producing an enzyme that is involved in the breakdown of large sugar molecules called glycosaminoglycans (GAGs). Mutations in the IDUA gene reduce or completely eliminate the function of the IDUA enzyme. The lack of IDUA enzyme activity leads to the accumulation of GAGs within cells, specifically inside the lysosomes. Lysosomes are compartments in the cell that digest and recycle different types of molecules. Conditions that cause molecules to build up inside the lysosomes, including MPS I, are called lysosomal storage disorders. The accumulation of GAGs increases the size of the lysosomes, which is why many tissues and organs are enlarged in this disorder.
Source: GARD

Question: Is Mucopolysaccharidosis type I inherited ?
Answer: How is mucopolysaccharidosis I (MPS I) inherited? MPS I is inherited from both parents in an autosomal recessive pattern.
Source: GARD

Question: What are the treatments for Mucopolysaccharidosis type I ?
Answer: What treatment is available for mucopolysaccharidosis I (MPS I)? The two main treatments for MPS I are enzyme replacement therapy (ERT) and bone marrow transplant. Both of these treatments work by replacing the missing IDUA enzyme. A drug called laronidase or Aldurazyme is the enzyme replacement therapy for MPS I. Treatment with laronidase can improve problems with breathing, growth, the bones, joints and heart. However, this treatment is not expected to treat problems with mental development because laronidase cannot cross the blood-brain barrier. A bone marrow transplant is another treatment option that provides the person with MPS I with cells that can produce the IDUA enyzme. A bone marrow transplant can stop the progression of neurological problems.
Source: GARD