Dilated Optic Nerve Sheath in Mucopolysaccharidosis I: Common and Not Necessarily High Intracranial Pressure

Hydrocephalus is one of the earliest manifestations of mucopolysaccharidosis I-Hurler syndrome, and delayed treatment of hydrocephalus can lead to neurocognitive delay or even death. Optic nerve sheath diameter has been established as a noninvasive measurement to detect elevated intracranial pressure. This study aimed to establish correlations between optic nerve sheath diameter and opening pressure. Forty-nine MR images and opening pressures in patients with mucopolysaccharidosis I-Hurler syndrome were retrospectively reviewed from 2008 to 2020. The optic nerve sheath diameter was measured 3 mm posterior to the posterior margin of the globe (retrobulbar) and 10 mm anterior to the optic foramen (midpoint segment), and the average was taken between the 2 eyes. Opening pressure was measured with the patient in the lateral decubitus position with controlled end-tidal CO2 on the same day as the MR imaging. The average retrobulbar optic nerve sheath diameter was 5.33 mm, higher than the previously reported measurement in healthy controls, in patients with idiopathic intracranial hypertension, and there was a positive correlation between age and the optic nerve sheath diameter measured at the retrobulbar or midpoint segment (retrobulbar segment, R 2 = 0.27, P < .01; midpoint segment, R 2 = 0.20, P < .01). However, there was no correlation between retrobulbar or midpoint segment optic nerve sheath diameter and opening pressure (retrobulbar segment, R 2 = 0.02, P = .17; midpoint segment, R 2 = 0.03, P < .12). This study shows a higher average optic nerve sheath diameter in patients with mucopolysaccharidosis I-Hurler syndrome than in healthy controls regardless of the location of the measurement. However, the degree of optic nerve sheath dilation does not correlate with opening pressure, suggesting that increased optic nerve sheath diameter is an ocular manifestation of mucopolysaccharidosis I-Hurler syndrome itself rather than a marker of elevated intracranial pressure.

Ultrasound findings of finger, wrist and knee joints in Mucopolysaccharidosis Type I

INTRODUCTION

Musculoskeletal findings in MPS can progress after enzyme replacement. Our aim was to examine synovial recesses, tendons, retinacula and pulleys using ultrasonography for structural and inflammatory changes.

MATERIAL AND METHODS

The wrist, metacarpophalangeal (MCP), proximal and distal interphalangeal (PIP and DIP) joints, the finger flexor tendons and the knee including entheses of quadriceps and patella tendons were assessed clinically. Ultrasonography of the various synovial recesses of the wrist as well as the extensor retinaculum, carpal tunnel, MCP, PIP and DIP joints of the second finger, extensor and flexor tendons, A1-5 pulleys and the knee joint including relevant entheses followed. Significance of differences between patient values and available normative data were assessed using t-tests.

RESULTS

Ultrasonography showed significant abnormal intraarticular material in the wrist without a clear distribution to synovial recesses and without effusions. Doppler signals were found in a perisynovial distribution and not intrasynovial as expected in in inflammatory arthritis. Findings were similar in the knee but not the fingers. Flexor and extensor tendons were also mostly normal in their structure but significant thickening of retinaculae and the flexor tendon pulleys was seen (p<0.0001 compared to normal).

CONCLUSION

MPS I patients showed intraarticular deposition of abnormal material in the wrist and knee but not in the finger joints where significant thickening of retinaculae/pulleys controlling tendon position was dominant. No ultrasound findings of inflammatory pathology were demonstrated but rather a secondary reaction to abnormal deposition and direct damage of GAG.

Whole genome sequencing for mutation discovery in a single case of lysosomal storage disease (MPS type 1) in the dog

Mucopolysaccharidosis (MPS) is a metabolic storage disorder caused by the deficiency of any lysosomal enzyme required for the breakdown of glycosaminoglycans. A 15-month-old Boston Terrier presented with clinical signs consistent with lysosomal storage disease including corneal opacities, multifocal central nervous system disease and progressively worsening clinical course. Diagnosis was confirmed at necropsy based on histopathologic evaluation of multiple organs demonstrating accumulation of mucopolysaccharides. Whole genome sequencing was used to uncover a frame-shift insertion affecting the alpha-L-iduronidase (IDUA) gene (c.19_20insCGGCCCCC), a mutation confirmed in another Boston Terrier presented 2 years later with a similar clinical picture. Both dogs were homozygous for the IDUA mutation and shared coat colors not recognized as normal for the breed by the American Kennel Club. In contrast, the mutation was not detected in 120 unrelated Boston Terriers as well as 202 dogs from other breeds. Recent inbreeding to select for recessive and unusual coat colors may have concentrated this relatively rare allele in the breed. The identification of the variant enables ante-mortem diagnosis of similar cases and selective breeding to avoid the spread of this disease in the breed. Boston Terriers carrying this variant represent a promising model for MPS I with neurological abnormalities in humans.

Ultrasonographic Features of Hip Joints in Mucopolysaccharidoses Type I and II

OBJECTIVES

The primary aim of this study was to assess the ultrasonographic features of hip joints in patients with mucopolysaccharidosis (MPS) type I and II in comparison with healthy population. The secondary aims were to correlate these features with clinical measures and to evaluate the utility of ultrasound in the diagnosis of MPS disease.

MATERIALS AND METHODS

Sixteen MPS I (n = 3) and II (n = 13) patients were enrolled in the present study and underwent clinical and radiological evaluation, and bilateral high-resolution ultrasonography (US) of hip joints. The distance from the femoral neck to joint capsule (synovial joint space, SJS), joint effusion, synovial hyperthrophy, and local pathological vascularization were evaluated. The results were compared to the healthy population and correlated with clinical and radiological measures.

RESULTS

1. There was a difference in US SJS between children with MPS disease and the normative value for healthy population (7mm). Mean values of SJS were 15.81 ± 4.08 cm (right hip joints) and 15.69 ± 4.19 cm (left joints). 2. No inflammatory joint abnormalities were detected in MPS patients. 3. There was a clear correlation between US SJS and patients' age and height, while no clear correlation was observed between SJS and disease severity.

CONCLUSIONS

1. Patients with MPS I and II present specific features in hip joint ultrasonography. 2. The data suggests that ultrasonography might be effective in the evaluation of hip joint involvement in patients with MPS and might present a valuable tool in facilitating the diagnosis and follow up of the disease.

Carotid intima-media thickness is increased in patients with treated mucopolysaccharidosis types I and II, and correlates with arterial stiffness

BACKGROUND

Treatments for mucopolysaccharidoses (MPSs) have increased longevity, but coronary artery disease (CAD) and cardiovascular complications cause mortality in a high percentage of patients. Non-invasive measures of sub-clinical atherosclerosis, such as carotid intima-media thickness (cIMT) and arterial stiffness, may be useful for prediction of CAD outcomes in MPS patients.

OBJECTIVES

The aim of the study was to determine if cIMT and arterial stiffness are abnormal in MPS I and II patients compared to healthy controls.

METHODS

MPS patients underwent carotid artery ultrasonography, and electronic wall-tracking software was used to measure cIMT, carotid artery cross-sectional compliance (cCSC), cross-sectional distensibility (cCSD), and incremental elastic modulus (cIEM). Control data from healthy subjects were obtained from a different study that utilized identical testing within the same laboratory.

RESULTS

A total of 406 healthy controls and 25 MPS patients (16 MPS I, 9 MPS II) were studied. All MPS patients had or were receiving treatment: 15 patients (6 MPS I, 9 MPS II) were receiving enzyme replacement therapy (ERT), 9 patients (all MPS I) had received hematopoietic stem cell transplant (HSCT), and 1 patient with MPS I had received HSCT and was receiving enzyme replacement therapy (ERT). MPS patients had significantly higher mean (± SD) cIMT (0.56 ± 0.05 mm) compared to controls (0.44 ± 0.04 mm; adjusted p<0.001). MPS patients also had increased stiffness compared to controls, showing significantly lower cCSC (0.14 ± 0.09 mm(2)/mmHg versus 0.16 ± 0.05 mm(2)/mmHg; adjusted p=0.019), and higher cIEM (1362 ± 877 mmHg versus 942 ± 396 mmHg; adjusted p<0.001). cCSD in MPS patients was lower than that of controls (29.7 ± 16.4% versus 32.0 ± 8.2%) but was not statistically significant; p=0.12. Among MPS patients, cCSD showed a significant association with cIMT (p=0.047), while the association between cIEM and cIMT approached significance (p=0.077). No significant differences were observed in cIMT, cCSD, cCSC, and cIEM between MPS I and MPS II patients.

CONCLUSIONS

Despite treatment, MPS patients had higher cIMT compared to healthy controls, indicating this marker of sub-clinical atherosclerosis may be a useful predictor of CAD outcomes. The association of arterial stiffness measures with cIMT suggests that mechanical and structural changes may occur in concert among MPS patients. Although yet to be confirmed, increased cIMT and arterial stiffness in MPS I and II patients may be a consequence of inflammatory signaling pathways triggered by heparan or dermatan sulfate-derived oligosaccharides. Prospective, longitudinal studies will need to be performed in order to evaluate the usefulness of these carotid measurements as predictors of adverse CAD outcomes in MPS patients.

Postnatal progression of bone disease in the cervical spines of mucopolysaccharidosis I dogs

INTRODUCTION

Mucopolysaccharidosis I (MPS I) is a lysosomal storage disorder characterized by deficient α-l-iduronidase activity leading to accumulation of poorly degraded dermatan and heparan sulfate glycosaminoglycans (GAGs). MPS I is associated with significant cervical spine disease, including vertebral dysplasia, odontoid hypoplasia, and accelerated disk degeneration, leading to spinal cord compression and kypho-scoliosis. The objective of this study was to establish the nature and rate of progression of cervical vertebral bone disease in MPS I using a canine model.

METHODS

C2 vertebrae were obtained post-mortem from normal and MPS I dogs at 3, 6 and 12 months-of-age. Morphometric parameters and mineral density for the vertebral trabecular bone and odontoid process were determined using micro-computed tomography. Vertebrae were then processed for paraffin histology, and cartilage area in both the vertebral epiphyses and odontoid process were quantified.

RESULTS

Vertebral bodies of MPS I dogs had lower trabecular bone volume/total volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and bone mineral density (BMD) than normals at all ages. For MPS I dogs, BV/TV, Tb.Th and BMD plateaued after 6 months-of-age. The odontoid process appeared morphologically abnormal for MPS I dogs at 6 and 12 months-of-age, although BV/TV and BMD were not significantly different from normals. MPS I dogs had significantly more cartilage in the vertebral epiphyses at both 3 and 6 months-of-age. At 12 months-of-age, epiphyseal growth plates in normal dogs were absent, but in MPS I dogs they persisted.

CONCLUSIONS

In this study we report reduced trabecular bone content and mineralization, and delayed cartilage to bone conversion in MPS I dogs from 3 months-of-age, which may increase vertebral fracture risk and contribute to progressive deformity. The abnormalities of the odontoid process we describe likely contribute to increased incidence of atlanto-axial subluxation observed clinically. Therapeutic strategies that enhance bone formation may decrease incidence of spine disease in MPS I patients.

The craniocervical junction following successful haematopoietic stem cell transplantation for mucopolysaccharidosis type I H (Hurler syndrome)

Mucopolysaccharidosis I Hurler (MPS IH) is a progressive multisystemic disorder caused by alpha-L-iduronidase deficiency. First choice of treatment in MPS IH children is haematopoietic stem cell transplantation (HSCT). The effect of HSCT has been shown to have limited influence on skeletal manifestations by poor penetration of musculoskeletal tissues by the enzyme derived from donor leucocytes. Aim of this study was to investigate the effect of HSCT on the craniocervical junction (CCJ) in Hurler patients. We analysed retrospectively sequential magnetic resonance imaging (MRI) scans of 30 patients with Hurler disease treated by HSCT since 1982 at the Royal Manchester Children's Hospital, UK, in order to determine whether the patients suffer from dens hypoplasia. Results were compared with biochemical and clinical characteristics: Enzyme activity (EA), chimerism, urinary glycosaminoglycan (GAG) excretion and neurological status. Investigations were part of standard clinical procedures. Results are descriptive in presentation. In 26/30 patients a determination of odontoid hypoplasia was feasible. The majority showed a normal dens length and an increase with age. Only 3/26 revealed a dens hypoplasia. One of them had only partial donor engraftment (DE) with reduced EA, one of them suffered from chronic graft versus host disease (GVHD). One patient with only partial DE and reduced EA presented with initial dens hypoplasia until preadolescence but normalized later on. There may be a trend towards lower EA and the occurrence of DH in transplanted MPS patients - perhaps the dosage of enzyme plays a role in the correction of skeletal complications in this patient group. HSCT patients with incomplete DE and therefore lower EAs may require special attention and care.

Cardiac abnormalities in adults with the attenuated form of mucopolysaccharidosis type I

BACKGROUND

Cardiac involvement in mucopolysaccharidosis type I (MPS I) has been studied primarily in its most severe forms. Cardiac involvement, particularly left ventricular (LV) systolic and diastolic function, in the attenuated form of MPS I is less well known.

METHODS

Cardiac function was prospectively investigated in 9 adult patients with the attenuated form of MPS I. All patients underwent 12-lead electrocardiography, 24 h Holter monitoring and two-dimensional echocardiography including tissue Doppler imaging (TDI). Eighteen age- and sex-matched healthy volunteers served as a control group.

RESULTS

Aortic, mitral and tricuspid valve thickening was seen in, respectively, 5 (56%), 4 (44%) and 2 (22%) patients. Moderate mitral valve stenosis was seen in 1 patient and moderate aortic stenosis in 2 patients. All patients had mild-to-moderate aortic and mitral valve regurgitation and 6 patients (67%) had mild-to-moderate tricuspid valve regurgitation. Despite normal LV dimensions, ejection fraction and mass index, MPS patients had lower mean systolic mitral annular velocities (6.1 +/- 0.6 vs 9.1 +/- 1.4 cm/s, p < 0.01) compared to normal control subjects. Similarly, mean early diastolic mitral annular velocities were lower in MPS patients (7.8 +/- 0.9 vs 13.3 +/- 3.3 cm/s, p < 0.01).

CONCLUSION

MPS I patients with the attenuated phenotype have not only valvular abnormalities but also LV diastolic and systolic abnormalities.

[Hurler's syndrome--early clinical suspicion]

BACKGROUND

Hurler's syndrome is a rare congenital metabolic disorder and is inevitably lethal when untreated. The presenting symptoms are usually vague, resembling those found in otherwise healthy children.

MATERIAL AND METHODS

We present a patient with Hurler's syndrome and discuss the unspecific clinical signs and symptoms seen in these patients based on a review of relevant literature.

RESULTS

A two-months-old infant boy was operated for a rightsided inguinal hernia. The anaesthesiologist had difficulty intubating the patient. During the following months the patient had a severe allergic reaction to vaccination, chronic rhinitis with recurrent upper airway infections, and diarrhoea and vomiting. Eventually, failure to gain weight, and psychomotoric delay led to a thorough clinical investigation. Extensive X-ray diagnostics and analysis of urine and serum concluded with Hurler's syndrome.

INTERPRETATION

Clinical vigilance is needed in the diagnosis of Hurler's syndrome. Early symptoms, such as rhinitis and hernia, are vague and unspecific. Radiological features, such as broad costae or gibbus, are helpful in obtaining the diagnosis. Decreased level of alpha-L-iduronidase in serum confirms the diagnosis of Hurler's syndrome. Patients tend to be treated symptomatically before the eventual diagnosis of this syndrome.

Combined aortic and mitral stenosis in mucopolysaccharidosis type I-S (Ullrich-Scheie syndrome)

The genetic mucopolysaccharidosis syndromes (MPS) are autosomal recessive inborn errors of metabolism. Heart valve involvement in MPS is not uncommon but only a few case reports of successful cardiac surgery are available. In particular, reports of combined aortic and mitral stenosis associated with MPS type I-S are very rare. Both type I and type VI MPS are associated with significant left sided valvar heart disease that requires surgical valve replacement because of irregular valve thickening, fibrosis, and calcification. A 35 year old man had severe mitral valve stenosis after successful surgical replacement of a stenotic aortic valve. Valvar heart disease was investigated by cardiac ultrasound and left heart catheterisation. Histomorphological characterisation of the affected mitral valve was performed. The case illustrates typically associated clinical features of cardiac and extracardiac abnormalities found in MPS type I-S.

Murine MPS I: insights into the pathogenesis of Hurler syndrome

Mucopolysaccharidosis type I (MPS I) is an autosomal recessive disease resulting from deficiency of the lysosomal enzyme alpha-L-iduronidase. A murine model which shows complete deficiency in alpha-L-iduronidase activity has been developed and shows phenotypic features similar to severe MPS I in humans. Here we report on the long-term clinical, biochemical, and pathological course of MPS I in mice with emphasis on the skeletal and central nervous system (CNS) manifestations. Affected mice show a progressive clinical course with the development of coarse features, altered growth characteristics and a shortened life span. Progressive lysosomal accumulation is seen in all tissues. Skeletal manifestations represent the earliest clinical finding in MPS I mice with histologic analysis of growth plate and cortical bone revealing evidence that significant early pathology is present. Analysis of the CNS has revealed the novel finding of progressive neuronal loss within the cerebellum. In addition, brain tissue from MPS I mice shows increased levels of GM2 and GM3 gangliosides. This murine model clearly shows phenotypic and pathologic features which mimic those seen in severe human MPS I and should be an invaluable tool for the study of the pathogenesis of generalized storage disorders.

Bony changes in common mucopolysaccharidoses

To evaluate the radiological features of mucopolysaccharidoses (MPS), 15 cases were collected for review in this hospital, retrospectively (1985-1995). Eight cases of Hurler syndrome, two cases of Hunter syndrome, two cases of Sanfilippo syndrome and three cases of Morquio syndrome were classified. Varying severity of dysostosis multiplex is the general bony manifestation of MPS, but special appearance may occur in particular types. Hurler syndrome is the prototype of MPS. The main findings were as follows: "J" shaped sella turcica, paddle-like ribs, anterior inferior beaking (hook-like) of lower thoracic-upper lumbar hypoplastic vertebral bodies, flared iliac wings, constrictive iliac bodies, diaphyseal expansion of long bones, distal ulna and radius tilt toward each other, bullet-like proximal phalanges and central pointing of proximal metacarpals. Hunter and Sanfilippo syndromes had the appearance of moderate to mild dysostosis multiplex. Morquio syndrome had distinctive bony changes as vertebral plana and tongue-like protrusion in the anterior part of the lower thoracic-upper lumbar vertebral bodies, particularly short of the distal deformed ulna and poor ossification of the proximal lateral tibial epiphyses. Although clinical presentations and the hallmarks of bony changes helped possible classification of MPS, definite diagnosis depends on enzyme analysis.

Diagnosis from single-digit radiography

This pictorial assay illustrates the value of plain radiographs of the digit in diagnosing disease in children. Although the hand is regarded as a mirror of disease, the finger often points to the correct diagnosis. The authors present a series of cases for which a coned-down view of a single digit is given. In some cases the findings indicate a specific diagnosis, whereas in others only a differential diagnosis is possible. The radiographic findings and a brief differential diagnosis, as well as the definitive diagnosis, are presented for each case.

Resting Tl-201 scintigraphy in the evaluation of coronary artery disease in children with Hurler syndrome

Severe coronary artery disease may occur early in the course of mucopolysaccharidosis. The authors present radiologic, scintigraphic, and pathologic findings in five patients with Hurler syndrome. Thallium-201 myocardial scintigraphy and selective coronary angiography obtained within 2 days to 6 months were correlated in five patients. Postmortem examination of the coronary arteries was obtained in one patient within hours of angiography. Interobserver agreement on grading of scintigraphic abnormalities was poor. Nonspecific findings on Tl-201 studies included septal abnormalities in all five patients. Scintigraphic findings were corroborated by angiography and postmortem results in only 3 of 5 patients. Our findings suggest that resting Tl-201 scintigraphy has limited value in the detection of coronary artery disease in patients with Hurler syndrome.

Mucopolysaccharidosis: thickening of dura mater at the craniocervical junction and other CT/MRI findings

Cranial CT and/or MRI imaging of 8 patients with mucopolysaccharidosis (MPS) was retrospectively evaluated. Two patients had MPS IH, 1 had MPS IS, 1 had MPS IVA and 4 had MPS IV. CT and MRI showed thickening of dura mater at the cranio-cervical junction, causing narrowing of the subarachnoid space, in all the patients examined. Spinal cord compression was detected in 4 patients. Other findings were: white matter alterations, mild to severe hydrocephalus, skull dysplasia and odontoid dysplasia. White matter alterations were evident as large areas and as multiple dispersed spots of prolonged T1 and T2 value. Reduced gray/white matter contrast was demonstrated on T2-weighted MRI images. It is important to examine the cranio-cervical junction carefully for thickening of dura mater in all patients with mucopolysaccharidosis examined by CT or MRI, because of the generally progressive clinical course of MPS. In patients with symptomatic cord compression, surgical intervention should be considered.

Hypertrophic cardiomyopathy in mucopolysaccharidoses: regression after bone marrow transplantation

Mucopolysaccharide storage disease (MPS) presents clinically with a broad spectrum of abnormalities, among which cardiovascular involvement has been described. The echocardiographic findings have recently been reported for the various types of MPS. Among these, asymmetric septal hypertrophy (ASH) has been documented. We present a case of a 9-year-old girl suffering from type I MPS, atypical variant, with echocardiographic signs of ASH. She was given a bone marrow transplant after which the hypertrophic cardiomyopathy regressed.

Articular manifestations of Scheie's syndrome

A patient with the clinical and biochemical features of Scheie's syndrome is reported. Radiological investigation has shown severe progressive juxta-articular cystic lesions, which have not, to our knowledge, previously been described in Scheie's syndrome.

[Cardiac involvement in mucopolysaccharidosis. Apropos of an echocardiographic study in 8 cases]

Of all the storage diseases, mucopolysaccharidosis is the one whose cardiac manifestations are probably the least well known. Clinical and above all echocardiographic findings of heart involvement were studied in 8 patients with mucopolysaccharidosis, including four with Hunter disease. The paucity of clinical manifestations was in sharp contrast with the highly informative echocardiographic results. Valvular dystrophy, usually of the left side of the heart, was the most common anomaly, with five patients affected. Whereas some valvular lesions had no consequences, others led to stenosis or incompetence. Asymmetrical hypertrophy of the septum was found in one patient. No patient had evidence suggestive of vascular involvement, in particular of the coronary arteries.

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.