Mucopolysaccharidosis type IVA (Morquio A): a close differential diagnosis of spondylo-epiphyseal dysplasia.

Patients with mucopolysaccharidoses (MPS) have a plethora of multisystemic manifestations depending on the particular type, and atypical presentations are not uncommon. MPS type IVA (Morquio A syndrome) has predominant musculoskeletal system involvement and corneal clouding with normal intelligence and can be misdiagnosed as primary skeletal disorders in clinical practice. The absence of corneal clouding with normal urinary glycosaminoglycans (GAGs) level in a proportion of patients with MPS IVA makes the correct diagnosis even more challenging for physicians. Healthcare providers across specialties should have a high degree of suspicion for MPS IVA in all patients with suspected spondylo-epiphyseal dysplasia as early diagnosis and early treatment significantly improve the clinical outcome and activity of daily living.

Activity of daily living for Morquio A syndrome.

The aim of this study was to evaluate the activity of daily living (ADL) and surgical interventions in patients with mucopolysaccharidosis IVA (MPS IVA). The factor(s) that affect ADL are age, clinical phenotypes, surgical interventions, therapeutic effect, and body mass index. The ADL questionnaire comprises three domains: "Movement," "Movement with cognition," and "Cognition." Each domain has four subcategories rated on a 5-point scale based on the level of assistance. The questionnaire was collected from 145 healthy controls and 82 patients with MPS IVA. The patient cohort consisted of 63 severe and 17 attenuated phenotypes (2 were undefined); 4 patients treated with hematopoietic stem cell transplantation (HSCT), 33 patients treated with enzyme replacement therapy (ERT) for more than a year, and 45 untreated patients. MPS IVA patients show a decline in ADL scores after 10years of age. Patients with a severe phenotype have a lower ADL score than healthy control subjects, and lower scores than patients with an attenuated phenotype in domains of "Movement" and "Movement with cognition." Patients, who underwent HSCT and were followed up for over 10years, had higher ADL scores and fewer surgical interventions than untreated patients. ADL scores for ERT patients (2.5years follow-up on average) were similar with the-age-matched controls below 10years of age, but declined in older patients. Surgical frequency was higher for severe phenotypic patients than attenuated ones. Surgical frequency for patients treated with ERT was not decreased compared to untreated patients. In conclusion, we have shown the utility of the proposed ADL questionnaire and frequency of surgical interventions in patients with MPS IVA to evaluate the clinical severity and therapeutic efficacy compared with age-matched controls.

Inestabilidad occipitocervical en la enfermedad de Morquio. Presentación de 2 casos y revisión de la literatura / Occipital-cervical instability in Morquio disease: a presentation of 2 cases and a review of the literature

Introducción. El síndrome de Morquio se produce por un déficit enzimático de herencia autosómica recesiva. Presenta numerosas manifestaciones musculoesqueléticas, entre las que destaca por su riesgo vital la inestabilidad atloaxoidea. En estos casos está indicada la cirugía de artrodesis (y descompresión) occipitocervical Objetivo. Se presentan 2 pacientes con síndrome de Morquio que precisaron de este tipo de cirugía, así como una revisión de la literatura. Pacientes y métodos. Dos pacientes: un niño y una niña, con síndrome de Morquio e inestabilidad cervical alta, con signos y síntomas neurológicos, que fueron intervenidos quirúrgicamente mediante descompresión y artrodesiso occipitocervical instrumentada; con un seguimiento de 6 y un año respectivamente. Resultados. Ambos pacientes mejoraron de sus problemas neurológicos, realizando en al actualidad una vida normal para su edad. Conclusión. La artrodesis occipitocervical con descompresión proporciona un entorno biomecánico seguro que previene de la afectación neurológica. Estaría indicada ante la aparición de sintomatología o de inestabilidad mecánica (AU)

Introduction. Morquio syndrome is caused by an inherited autosomal recessive enzyme deficiency. It presents with numerous musculoskeletal anomalies, among which atlantoaxial instability is highlighted, due it being life-threatening. Occipital-cervical arthrodesis surgery (and decompression) is indicated in these cases. Objective. The cases of 2 patients with Morquio syndrome that required this type of surgery are presented, along with a review of the literature. Patients and methods. Two patients: one boy and one girl, with Morquio syndrome and high cervical instability, with neurological signs and symptoms, who were subjected to surgery using decompression and instrumented occipital-cervical arthrodesis and followed up for 6 months and one year, respectively. Results. The neurological problems of both patients improved, and are currently having a normal life for their age. Conclusion. Occipital-cervical arthrodesis with decompression provides a safe biomechanical environment that prevents neurological involvement. It should be indicated before the appearance of symptoms or mechanical instability (AU)

Inspiratory muscle training in Morquio's syndrome: a case study.

We reported a case of MPS IV A presented with dyspnea on exertion and respiratory muscle weakness. The patient underwent inspiratory muscle training (IMT) using threshold loading for 18 weeks. After 6 weeks of initial IMT, aerobic exercise training consisting of walking was added to the treatment program. Inspiratory muscle strength increased 70%, and 6-minute walk test (6MWT) distance increased to 47 m. With the inclusion of aerobic exercise training, additional increases in inspiratory muscle strength (7%) and 6MWT distance (26.5 m) were obtained. Exertional dyspnea improved from severe to slight after 6 weeks of IMT, and to very slight after additional 12 weeks of combined aerobic training and IMT. Health-related quality of life improved especially in social function, emotional function, vitality, and physical role. In conclusion, inspiratory muscles can be trained with the improvement of muscle strength in a patient with Morquio's syndrome.

Morquio syndrome: a rehabilitation perspective.

Morquio Syndrome (mucopolysaccharidosis type IV A) is a rare inherited connective tissue disorder characterized by skeletal dysplasia, restrictive pulmonary disease and normal intelligence. Tetraplegia secondary to subluxation of C1 over C2 because of odontoid dysplasia is a common occurrence in these patients but there are limited descriptions regarding their specific physiatric management. Two patients (aged 20 and 17 years) were admitted to a pediatric rehabilitation facility after cervical spine stabilization following recurrent tetraplegia (C4 ASIA C and C4 ASIA D). Following surgery, patients were ventilator dependent and aphonic. One patient was successfully weaned off the ventilator to nocturnal BiPAP, while the other was able to tolerate three hours of ventilator free time despite being ventilator dependent for ten years. At discharge, both patients showed significant improvement in mobility, self care skills and communication abilities. Functional independence was encouraged through use of various assistive devices for mobility, activities of daily living (ADL) and communication. Group counseling and peer support were extremely helpful in their adjustment to disability. Physiatric intervention is essential and requires understanding of the unique impairments encountered by tetraplegics with Morquio Syndrome.