Nurul Muhammad Prakoso1, Rizky Priambodo2, Yulia Ariani3, Cut Nurul Hafifah4, Damayanti Rusli Sjarif4
1Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Jakarta, Indonesia
2Human Genetic Research Center, Indonesian Medical Education and Research Institute, Universitas Indonesia, Jakarta, Indonesia
3Human Genetic Research Center, Indonesian Medical Education and Research Institute, Universitas Indonesia; Department of Pediatric, Universitas Indonesia, Cipto Mangunkusumo Hospital; Department of Medical Biology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
4Human Genetic Research Center, Indonesian Medical Education and Research Institute, Universitas Indonesia; Department of Pediatric, Universitas Indonesia, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
DOI: 10.4103/jnsbm.JNSBM_40_19
ABSTRACT
Objective: Mucopolysaccharidosis IVA (MPS IVA), or Morquio A syndrome, is a lysosomal storage disorder caused by a deficiency of galactosamine (N-acetyl)-6-sulfatase (GALNS) enzyme that leads to the accumulation of keratan sulfate and chondroitin-6-sulfate in the lysosome and eventually in the tissue or organ damaged. This enzyme deficiency occurs because of mutations in the galactosamine (N-acetyl)-6-sulfatase (GALNS) gene located at locus 16q24.3. GALNS comprises 14 exons, has a size of ~43 kb, and encodes 522 amino acids. Currently, 47 of 368 mutations have been detected in exon 5, indicating that this region is a hotspot of mutations. The objective of this study was to analyze the mutations in exon 5 of GALNS in MPS IVA patients in Indonesia. Materials and Methods: Genomic DNA was isolated from fresh blood samples obtained from patients with MPS IVA and normal individuals at Cipto Mangunkusumo Hospital. Exon 5 of GALNS was amplified using a pair of specific primers, and polymerase chain reaction products were sequenced using an automated sequencing technique. Results: We found a novel missense mutation c.503G>T that alters the amino acid at position 168 from glycine to valine (G168V). Three previously reported variations identified in this study are c.510T>C (Y170), c.566 + 5T>C, and IVS5 + 134G>A. Conclusion: This finding provides new data about variants in exon 5 of GALNS. Further, research is needed to identify variations in other exons and to map the mutation profile in MPS IVA patients in Indonesia.
Keywords: GALNS, mucopolysaccharidosis IVA, mutation, variation.