Airway obstruction in Hurler's syndrome--radiographic features

The mucopolysaccharidosis (MPS) diseases are progressive clinical disorders which are characterized by a deficiency of lysosomal enzymes. In MPS I (Hurler's syndrome), reduced activity of alpha-L-iduronidase leads to intralysosomal storage of dermatan and heparan sulfate in various tissues. Airway obstruction is a frequent problem in these patients, often secondary to abnormal cervical vertebra, a short neck, a high epiglottis, and mucopolysaccharide infiltration of the soft tissues in the upper aerodigestive tract. Evaluation of these abnormalities may include plain film and videofluoroscopic examinations of the airway. The therapeutic and diagnostic implications of such studies are discussed in a review of 4 patients with Hurler's syndrome manifesting upper airway obstruction.

A radiological presentation of neonatal and infantile syndromes

The syndromes I have described are unfortunately not rare in Saudi and so the role of genetic counselling is an important, if difficult, one. Consanguinous marriages are a key cause of these diseases, but not one easily avoided. Marriage rituals in this part of the world are vastly different from those in the west. Many Saudis regard consanguinous unions, for example between cousins, as a further strengthening of family bonds. The role of genetics is not fully appreciated by parents and genetic disease is often attributed to other, extraneous causes: God's will; an illness suffered by the mother during pregnancy; or to the 'evil eye.' Even when genetic counsellors actively discourage parents who are at risk from having future children, this advice goes unheeded. Parents prefer to rely on: 'Insh'allah' or God's will' to safeguard them. Abortion is strictly prohibited by religious law and any affected offspring are cared for by a dedicated and loving family under the guidance of the Holy Qu'ran. They are rarely institutionalized.

[Clinical features and X-ray manifestations of mucopolysaccharidosis-II-B]

Mucopolysaccharidosis-II (MPS-II) and MPS-I are both characterized by gargoylist dwarfism. MPS-II is of X-linked recessive heredity. Five cases of MPS-II-B in our series were followed up for ten years. Corneal opacity and dysmnesia were not found in all of them. Although MPS-II possessed many radiologic similarities to MPS-I, the former presented certain characteristic features such as butterfish-like vertebra, and small triangular malformation of carpal bones and tarsal scaphoid etc.

Radiographic findings in a canine model of mucopolysaccharidosis I. Changes associated with bone marrow transplantation

Eight dogs with mucopolysaccharidosis I (MPS I) were studied and their radiographic lesions compared with those reported in human MPS I. Three of the dogs received bone marrow transplants from unaffected littermates at 5 months of age. These dogs, and two affected control littermates were radiographed at 3, 6, 9, 12, 15, 18 and 20 months post-transplantation to evaluate the effects in chondro-osseous tissues. Although bone marrow transplantation did not alleviate all radiographically detectable changes, there was delayed onset of some lesions and reduced severity of most lesions in the dogs receiving transplants. Those lesions most closely associated with clinical lameness or gait abnormalities in untreated canine MPS I were most improved (or eliminated), and this was reflected in marked clinical improvement.

Radiological findings in patients with mucopolysaccharidosis I H/S (Hurler-Scheie syndrome)

The development of radiological changes in two patients with mucopolysaccharidosis (MPS) Type I H/S is described. Radiological findings reveal enlargement of the sella in one patient, impression of the basilar skull in the other patient. Sclerosis and thickening of the base of skull was observed in both patients. The mandibular necks were short with striking flattening of the superior surfaces of the condyles, when the patients reached adult age. At the age of 12, hypertelorism and spaced teeth were already present in both patients. In addition, they showed early costal, clavicular and scapular changes, irregularities of the acromial joints and acetabulae, hypoplasia of the inferior portion of the iliac bones and flared iliac wings. The flat femurs had short metaphyses and were held in valgus position. Development of dentigerous cysts as well as mandibular changes seem to be rather specific for this variant of alpha-L-iduronidase deficiency. In contrast to the classical form of MPS I, skeletal changes of the spine and hands are minimal.

The stylohyoid ligament in Hurler syndrome and related conditions: comparison with normal children

The stylohyoid ligament is seen on lateral radiographs of the neck to be normally calcified to some extent in approximately 25% of all children between ages 1 1/2 and 15. When it appears, the ossification pattern is a relatively thin configuration in 90% of children. In 8 out of 9 children with Hurler syndrome, the stylohyoid was calcified, and was thicker than in normal children. This finding illustrates the nature of the stylohyoid ligament as a bone analogue, and its participation in the skeletal deformation pattern of dysostosis multiplex.

Diagnosis of Hurler's syndrome with chest roentgenogram

Hurler's syndrome is usually diagnosed by chemical means; however, characteristic roentgenographic findings of "hook-shaped" vertebral bodies or "oar-shaped" ribs may be helpful in diagnosing the disorder.

[Mucolipidosis. biologic characteristics (author's transl)]

Mucolipidosis II is a severe inherited lysosomal storage disease characterized by profound psychomotor retardation, severe Hurler-like skeletal changes and normal urinary mucopolysaccharide excretion. Mucolipidosis II is a related disorder distinguished by its milder course, milder to absent mental retardation and survival to adult life. Cultivated fibroblasts from patients with both of these disorders display large inclusions on phase microscopy and reduced levels of many acid hydrolases. However, culture medium fibroblasts out the body fluids of affected patients show enormously elevated levels of these hydrolases. The lysosomal enzyme activities in serum, leukocytes, fibroblasts extracts and culture medium from seven patients with mucolipidosis II are similar to those found in four cases of mucolipidosis III. The findings of excessive excretion of sialyl-oligosaccharide in urine and of increased level of sialic acid compounds in cultured fibroblasts associated with a sialidase deficiency in leukocytes, fibroblasts and serum are discussed.

Atypical Hurler syndrome without alpha-L-iduronidase deficiency

Three atypical patients with clinical and laboratory findings of Hurler syndrome, but without alpha-L-iduronidase deficiency, are described. Clinical features included characteristic facies, mental retardation, corneal clouding, dysostosis multiplex, restriction of joint mobility, and hepatosplenomegaly. Excessive amounts of chondroitin sulfate B and heparitin sulfate were excreted in the urine. alpha-L-Iduronidase activities in leucocytes and liver tissues were within the normal range or somewhat elevated.