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CLINICAL MANIFESTATION

Hunter syndrome is a disease with multiorgan and multisystem involvement that has a variable

age of onset and a variable rate of progression. The phenotypic expression spans a wide

spectrum of clinical severity. The signs and symptoms of Hunter syndrome are thought to be

mainly results of accumulation of GAG within tissues and organs.

General Appearance and Skeletal Abnormalities

Patients typically appear normal at birth. The most common presenting feature is a coarsening of

facial features, which becomes apparent between 2 and 4 years of age. The patients tend to have

broad noses with flared nostrils and large jowls. The lips may be thick, and they may have an

enlarged protruding tongue. The head is of large circumference throughout life. Patients tend to

be tall for their age until 4 or 5 years of age. The ribs are thickened and have an unusual shapeand clavicles can be increased in bulk. Patients with Hunter syndrome often walk on their toes

because of joint stiffness and tight heel cords.

Eyes

Retinal dysfunction can be found in patient with Hunter syndrome, it is evident by using

electroretinography. Ophthalmoscopy has revealed bilateral pigmentary changes and the loss of

field of vision in some patients. This loss of vision is underrecognized in Hunter syndrome, for

which screening should be performed on a regular basis. Other findings include disk swelling

and scleral thickening, which may cause optic nerve compression. Glaucoma is not a common

finding in Hunter syndrome.

Ear, Nose, and Throat

Frequent upper respiratory infections occur in most patients with Hunter syndrome. The enlarged

tongue, hypertrophic adenoids and tonsils, and skeletal changes in the jaw and neck that limit the

opening of the mouth all contribute to respiratory problems. Most patients have recurrent ear

infections, and nearly all of them experience progressive hearing loss. The hearing loss is caused

by both conductive and sensorineural deficits.The teeth become irregular and gingival tissue is

hyperplastic and hypertrophic.

Gastrointestinal Involvement

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Because of GAG storage, the liver and spleen of patients with Hunter syndrome are often

enlarged, resulting in abdominal distention. Beside that umbilical hernia is commonly seen in

patient with Hunter syndrome.

Respiratory System

Progressive airway obstruction is a common finding in Hunter syndrome, and complications are

a common cause of death. Contributing factors include narrowed and abnormally shaped trachea

and bronchi, enlarged tongue, hypertrophic adenoids and tonsils, large epiglottis, frequent upper

respiratory infections, and recurrent pneumonia. Restricted movement of the temporomandibular

joints, stiffness of the chest wall, and abdominal distention also inhibit normal breathing. A

common complication of the airway obstruction seen in Hunter syndrome is sleep apnea.

Cardiovascular System

Cardiac disease is present in almost all patients with Hunter syndrome and is a major cause of

death in this population. Signs and symptoms of heart disease present as early as 5 years of age.

Valvular disease, which leads to right and left ventricular hypertrophy and heart failure, are

commonly reported.

Skin

The skin of patients with Hunter syndrome may be thickened and inelastic. Patients with Hunter

syndrome may have a distinctive skin lesion, which is described as ivory-white papules that are 2to 10 mm in diameter, often coalescing to form ridges.

Neurologic Involvement

Death usually occurs in these severely affected patients in the first or second decade of life,

usually because of obstructive pulmonary disease, cardiovascular disease, neurologic problems,

or a combination of these and other factors. Spinal cord compression also may occur because of

narrowing of the spinal canal1 and instability of the atlantoaxial joint.