METHODS: A total of 195 5- and 6-year-old preschoolers were recruited from children attending Hospital Selayang, Selangor, Malaysia, to test the app. Uncooperative children and those with visual acuity of >logMAR 0.6 were excluded. Results from parents and the screening doctor using the app (Lea symbols) to test visual acuity were compared to each other and to gold standard vision testing by an optometrist using the Lea symbols chart.
RESULTS: Children 5 years of age represented 46.7% of the study population. The mean age of parents was 37.27 ± 7.68 years. Bland-Altman scatterplot agreement between assessors mainly was within the 95% confidence interval for bilateral eyes screening. Parents obtained a sensitivity of 86.6% (right vision) and 79.5% (left vision) and specificity of 78.9% (right vision) and 71.8% (left vision). Parents took a mean of 191.2 ± 70.82 seconds for bilateral screening. The intraclass correlation coefficient between optometrist and parents in bilateral eyes screening was good (P 0.7, indicating high internal reliability of the app. Most parents (178/195 [91.3%]) strongly agreed on the app's acceptability and ease of use.
CONCLUSIONS: The AAPOS Vision Screening App used by parents is a promising tool for visual acuity screening among Malaysian preschool children and a reliable app for vision screening.
METHODS: This is a multicentre descriptive case series of 21 patients comprising all MPS IVA patients in Malaysia. Mutational analysis was performed by PCR and Sanger sequencing of the GALNS gene in 17 patients.
RESULTS: The patients (15 females and 6 males) had a mean age (± SD) of 15.5 (± 8.1) years. Mean age at symptom onset was 2.6 (± 2.1) years and at confirmed diagnosis was 6.9 (± 4.5) years. The study cohort included patients from all the main ethnic groups in Malaysia - 57% Malay, 29% Chinese and 14% Indian. Common presenting symptoms included pectus carinatum (57%) and genu valgum (43%). Eight patients (38%) had undergone surgery, most commonly knee surgeries (29%) and cervical spine decompression (24%). Patients had limited endurance with lower mean walking distances with increasing age. GALNS gene analysis identified 18 distinct mutations comprising 13 missense, three nonsense, one small deletion and one splice site mutation. Of these, eight were novel mutations (Tyr133Ser, Glu158Valfs*12, Gly168*, Gly168Val, Trp184*, Leu271Pro, Glu320Lys, Leu508Pro). Mutations in exons 1, 5 and 9 accounted for 51% of the mutant alleles identified.
CONCLUSIONS: All the MPS IVA patients in this study had clinical impairments. A better understanding of the natural history and the clinical and genetic spectrum of MPS IVA in this population may assist early diagnosis, improve management and permit timely genetic counselling and prenatal diagnosis.