Hunter Syndrome, (Mucopolysaccharidosis type II) A Simple Guide To The Condition, Diagnosis, Treatment And Related Conditions

This book describes Hunter Syndrome, Diagnosis and Treatment and Related Diseases
Hunter syndrome (Mucopolysaccharidosis type II) is a very infrequent, inherited genetic disorder produced by a missing or malfunctioning enzyme.

Since the body does not have enough of the enzyme to break down certain complicated molecules, the molecules accumulate in harmful quantities.

In Hunter syndrome, the accumulation of huge quantities of these harmful substances ultimately causes permanent, progressive injury involving:
1.Appearance,
2.Mental development,
3.Organ function and
4.Physical abilities
Causes
Hunter syndrome (MPS II) is a familial disorder.
This indicates that it is inherited (passed down) through families.
The disorder is X-linked recessive (Xq28).
Boys are most often involved because their X chromosome is inherited from their mothers.
Their mothers may not have symptoms of the disease as they carry a nonworking copy of the gene.
Hunter syndrome forms when a defective X chromosome is inherited from the child's mother.
Due to that defective chromosome, an enzyme that is required to break down complex sugar molecules is absent or malfunctioning.
Without this enzyme, large quantities of these complex sugar molecules accumulate in the cells, blood and connective tissues, producing permanent and progressive injury.
Hunter syndrome is formed because of the lack of the enzyme iduronate sulfatase.
Without this enzyme, chains of sugar molecules collect in various body tissues, producing damage.
The early-onset, severe type of this disease starts shortly after age 2.
A late-onset, milder type causes less serious symptoms to occur later in life.
Symptoms
In the early-start, severe form, the symptoms are:
1.Aggressive behavior
2.Hyperactivity
3.Mental function gets worse over time
4.Severe intellectual disability
5.Jerky body movements
In the late or mild type, there may be mild to no mental deficiency.
In both forms, symptoms are:
1.Carpal tunnel syndrome
2.Coarse features of the face
3.Deafness (gets worse over time)
4.Increased hair growth
5.Joint stiffness
6.Large head
Diagnosis:
A physical exam and tests may show:
1.Abnormal retina (back of the eye)
2.Reduced iduronate sulfatase enzyme in blood serum or cells
3.Heart murmur and leaky heart valves
4.Enlarged liver
5.Enlarged spleen
6.Hernia in the groin
7.Joint contractures (from joint stiffness)
Tests may be:
1.Enzyme study
2.Genetic testing for a change in the iduronate sulfatase gene
3.Urine test for heparan sulfate and dermatan sulfate
Babies born with Hunter syndrome almost always seem healthy at birth.
Changes in facial appearance are often the first observable sign that something is not right.
Blood, urine or tissue samples can be examined for the deficient enzyme or for excess quantities of the complex sugar molecules in this disorder.
A genetic analysis can confirm the diagnosis.
Treatment:
There is no curative treatment for Hunter syndrome.
The treatment focuses on treating signs, symptoms and complications to provide some relief for the child as the disease worsens.
Respiratory complications
Removal of tonsils and adenoids can widen the child's airway and help alleviate sleep apnea.
Heart complications
The child's doctor will need to monitor closely for cardiovascular complications, such as high blood pressure, heart murmur and leaky heart valves
Neurological complications
The child's doctor may advise surgery to drain out excess fluids from brain.
The doctor may give anticonvulsants for seizures
Medicines such as sedatives and melatonin can improve sleep.
Enzyme replacement therapy and gene t

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