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

Abstract

Mucopolysaccharidosis IV A, better known as Morquio-A syndrome, is a rare condition with severe skeletal and multiorgan involvement. Sometimes is not easy to differentiate from other skeletal dysplasias. Prior to definitive diagnosis, patients have been delayed or misdiagnosis due to lack of knowledge of local physicians about this disease. The aim of this study is to compare the age of onset of clinical manifestations, age of diagnosis, as seen by the parent or primary caregiver and compare this age with other population reports worldwide. Self-administered questionnaires were conducted to the primary caregiver of confirmed patients, collecting information about the onset of symptoms, age, previous diagnoses and biological variables (age, gender, sex). Data from 50 patients, 23 men and 27 women was obtained. Mean age at definitive diagnosis was 5.6 years, age at onset of signs or symptoms was 4.14 years starting with pigeon chest deformity, valgus knees at 4.5 years, stiff hands and increasing mobility of wrists to the 5.8 years, followed by limitation to lift shoulders to 7.1 years. In 78% of patients the diagnosis was by a geneticist. First and subsequent observed clinical changes were orthopedic, starting as early as 4.4 years as noted by parents. Rise of suspicious may delay 16 months' average to definitive diagnosis based on other multi-systemic findings. The most frequent specialist aid in diagnosis is a clinical geneticist followed by orthopedic surgeon. The diagnosis of Morquio-A disease in Mexico is as early as reports from other centers.

Keywords: Mexico; Morquio-A syndrome; delay diagnosis; diagnosis; dwarphism; height; orphan disease; skeletal dysplasia.

Figure 1.

Height according age in Morquio-A patients. Notice all of them are between 90 and 110 cm. Most patients reach final height during second decade of life.

Figure 2.

Clinical features of Morquio-A patients. (A), Progressive inability to raise arms upperhead and full extend elbows, pigeon chest and relative short neck; (B), Wrist, elbow and hand deformations; (C), Severe genu valgus. Personal archive files. Patient and guardian consent was obtained prior attachment of present clinical images.