HURLER SYNDROME: A CASE REPORT AND A REVIEW OF THE LITERATURE

S.A. Malik, K. Imrani, N. Allali, S. El Haddad and L. Chat Pediatric Imaging Department, Pediatric Teaching Hospital-Rabat-Morocco. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 05 March 2020 Final Accepted: 07 April 2020 Published: May 2020

17 ligament extending over 34 mm with spine compression. A general treatment with enzymotherapyhas been started and the child is waiting for a bone marrow transplant.
Patients with Hurler syndrome present with multi-systemic involvement, including developmental delay, hepatosplenomegaly, dysostosis, arthropathies and a "gargoyle"facies. Their auditory, visual, respiratory and cardiovascular functions are also affected. Clinical signs appear from the first 2 years of life, life expectancy being around 10 years. [1,4,6] The child is born after a normal pregnancy, neonatal examination is normal but a giant mongoloid spot as well as a megacornatecan be observed. The signs appear gradually, during the first year of life. The diagnosis is usually made under the observation of visceral and orthopedic signs between the 4th and the 18th months.
The clinical picture usually move towards multi-visceral involvement, but symptomatology that is often partial and the slow evolution of moderate forms make the diagnosis often difficult. Certain diagnosis is only retained after biochemical proof of the enzyme deficiency. [7,9,4] Clinical manifestations of the different types of MPS vary from one type to another. The involvement of the central nervous system is characteristic and MRI remains the imaging of choice to assess cerebral and spinal cord abnormalities. [2,6,8] Skeletal anomalies are grouped under the term of multiple dysostosis and are elements of orientation towards MPS [5].
Several aspects are found :Skull (macrocephaly, premature closure of the sagittal suture , saddle turcica flared in the shape of a J, malformation of the teeth…),chest (short and thick collarbones, enlarged ribs, tapered at their insertion vertebral…), spine (antéro-superior hypoplasia of the vertebral bodies of the thoracolumbar hinge, oval vertebral bodies , reduced in height or flattened, secondary thoracolumbar kyphosis ), long bones (metaphyseal and diaphyseal enlargement, delay epiphyseal ossification). [5,6] Neurological aspects are characterized by anomalies common to all MPS (perivascular spaces increase, white matter anomalies, ventriculomegaly, cortico-subcortical atrophy) without anyspecific radiologicalabnormality being demonstrated or any correlation between the anomalies observed and the clinical severity [2,6,11].
On MRI, we typically found a white matter cribriform appearance, corpus callosum and basal ganglia, due to accumulation of GAG in Virchow Robin spaces, represented by multiple deep pseudo lacunar images that appear to be located in the white matter but actually correspond to spaces expansion [6].
We can also notice a white matter signal abnormality predominantly periventricular and in the oval centers suggesting gliosis, edema, or demyelination. Cortical atrophy are frequently observed, and arachnoid cysts are occasionally seen.
In addition, MR spectroscopy shows a broad peak around 3.7 ppm, considered to contain signals from accumulated GAG.
Enzyme replacement therapy consists on intravenous administration of the recombinant alpha-L-iduronidase enzyme at regular intervals, which reduces lysosomaloverload and thus improves some clinical signs [7]. However, it does not cross the hematopoietic barrier, hence its low neurological efficiency. In addition, its high cost reduces its 18 accessibility. Hematopoietic stem cell transplantation is currently the treatment of choice in Hurler's disease, especially when performed early before the onset of psychomotor developmental delay. [3,7,10] These treatments should be combined with psychological support and genetic counseling. The genes of the different enzymes involved are now located and many mutations have been identified. Prenatal diagnosis is possible on culture of amniotic cells. [3,10] Whatever the form of treatment chosen, early diagnosis remains a key success factor essential to hope to prevent the appearance of irreversible lesions and increase the benefits of treatment.

Conclusion:-
Patients with Hurler disease must benefit from a multidisciplinary and global diagnostic approach, before any biological confirmation. This allows exploring and treating multi-systemic disorders that this condition generates, at the early stage, since symptomatic treatment is of certain importance.
It therefore seems essential that everyone be aware of clinical signs of mucopolysaccharidosis type I in order to undertake early appropriate additional examinations and optimize therapeutic management.
Enzyme treatment alternatives generates great hope for patients because of its effectiveness on non-neurological disease symptoms, but its high cost limits its accessibility.