Diagnosis of Morquio-A patients in Mexico: How far are we from prompt diagnosis?

Misdiagnosis in mucopolysaccharidoses

Mucopolysaccharidosis (MPS) is a group of 13 hereditary metabolic diseases identified in humans (or 14 diseases if considering one MPS type described to date only in mice) in which an enzymatic defect results in the accumulation of glycosaminoglycans (GAG) in the lysosomes of cells. First of all, as a result of GAG storage, the proper functioning of the lysosome is disturbed; then, the cells, and finally, tissue, organs, and the whole organism malfunctions are observed. Due to the rarity, heterogeneity, and multi-systemic and progressive nature of MPS, they present a major diagnostic challenge. Due to the wide variation in symptoms and their similarity to other diseases, MPS is often misdiagnosed, usually as neurological diseases (like autism spectrum disorders, psychomotor hyperactivity, and intellectual disability) or rheumatology and orthopedic disorders (like juvenile idiopathic arthritis, Perthes disease, rickets, and muscular dystrophy). In this review article, we present the problems associated with the possibility of misdiagnosing MPS, discuss what diseases they can be confused with, and suggest ways to reduce these problems in the future.

Bilateral Perthes Masking Morquio Disease

INTRODUCTION

Perthes disease radiography can mask other diseases. Properly observing the X-ray and changes in other joints helps to discard Perthes-like conditions. Association with changes in other systems, as well as the pathological history and even the examination of family members can help diagnose early attenuated cases of rare diseases.

CASE PRESENTATION

The case of a girl with hip pain, limp and doubtful radiographs is presented. Perthes disease was diagnosed elsewhere and physical therapy and analgesics were prescribed. As a second opinion, family look for another orthopedic physician, who looks beyond hip pain and limp. Full body X-rays are suggestive of skeletal dysplasia. Metabolic disease diagnosis is suspected with pathological history of the younger brother, with repetitive respiratory infections, as well as abnormal X-ray panel. Multiple dysostoses in both patients are demonstrated. The above findings help to diagnose Morquio disease in an attenuated variant after molecular examinations.

CONCLUSION

Early diagnosis in progressive diseases is essential to avoid progression to multi-organ deterioration. It is important that physician become familiar with habitual characteristics of Perthes disease on the pelvis radiograph, in order to unsure the error in the diagnosis.

Diagnosis is in the Eye of the Beholder: Barriers to Early Diagnosis of Mucopolysaccharidosis in Children in India

The present study examined referral pattern and diagnostic practices for mucopolysaccharidosis (MPS) in India in 40 patients with a confirmed diagnosis. Time lag between age of onset of symptoms and consultation with primary physician ranged from 0 to 84 months, between consultation with primary physician and visit to genetic clinic of 0 to 128 months, from visit to genetic clinic and diagnosis of 1 to 111 months, and that between onset of symptoms and diagnosis 1 to 154 months. Major causes for delayed diagnosis were symptoms overlooked by physician (54%), late consultation by care giver (48.6%), late onset of symptoms (43.2%), and resource crunch (32.4%). Diagnosis at referral other than MPS was noted in 45%. Thus, diagnostic delay for MPS is common due to health seeking practices of parents, as well as physicians' clinical practices. Overcoming these barriers would necessitate strengthening awareness and educational activities for physicians and lay public.

Diagnosis of Mucopolysaccharidosis Based on History and Clinical Features: Evidence from the Bajio Region of Mexico

Introduction Mucopolysaccharidosis (MPS) are infrequent deposit diseases; generally, the diagnosis is delayed until symptoms appear. Age or presentation is related to the severity of the disease. A substantial number of patients are misdiagnosed since they describe nonspecific initial symptoms and signs in common. The aim of this study is to describe the common characteristics of patients with mucopolysaccharidosis already diagnosed, treated in hospitals of the Guanajuato Health System, with a special focus on early manifestations in order to review early clinical suspect manifestations. Methods A multicenter, descriptive, observational study was conducted to evaluate the cases of mucopolysaccharidosis treated and diagnosed. The study was carried out in the Pediatric departments of five big important hospitals of Bajio Mexico region in the period from February to August 2016. Results Eighteen patients were identified, 13 men and five women, with an average age of 8.6 years. The most frequent mucopolysaccharidosis was type IV A (Morquio) in seven patients, followed by type I (Hurler) in four patients, three patients for type III (San Filippo), two patients for type II (Hunter), and two patients for type VI (Maroteaux-Lamie). The commonest clinical manifestations at diagnosis were dimorphism, triangular dorsal hump, skeletal alterations (genu valgus, short stature, and flat feet), and a limited range of movement in the major joints. Non-skeletal manifestations, such as an umbilical/inguinal hernia and hepato-splenomegaly, were very frequent. In a majority of patients with mucopolysaccharidosis, the radiological data of the disease were found: they were most severe in type IV and type VI, mild in type I and II, and none in MPS III. A diagnosis was made in all patients by a clinical and radiological evaluation and confirmed by an enzymatic study. Conclusions In all rare diseases, a suspicion diagnosis is based on subtle characteristics that manifest themselves in a few different organs and systems may be mild. Suspicion by the physician and the need to strengthen collaboration patterns between different specialities play an important role in the early diagnosis and treatment of these conditions.