Extended Abstract
1. Introduction
This case report article presented two patients with the same genetic disease. In both cases, the genetic mutation causing the disease was detected. Besides, for the first time in the world, a new mutation was observed.
Wang et al. (2010) studied 24 Chinese patients with Morquio A Syndrome (MPS IVA). They observed 27 pathogenic mutations in the GALNS gene of these patients; of which, 16 mutations were reported prior to their study. Approximately 63% of the mutations they observed in these patients were not detected elswewehre, globally. Their prediction was that some of these mutations may be specific to this population. The G340D mutation was the most common type in this population [1]. Caciotti A et al. genetically analyzed 21 MPS patients, and 4 of whom presented Morquio B syndrome. As a result of determining the GLB1 gene sequence in these 4 patients, c.443G>A mutation was observed in one of the patients for the first time [2]. The current study aimed to find the mutations that caused Morquio syndrome in two Iranian children.
2. Materials and Methods
The present study investigated two patients with Morquio syndrome. Moreover, both patinets were from consanguineous marriage and referred to Dr. Zinley’s medical genetics laboratory through their specialist physician. The required blood samples were obtained from the study patients and their parents. The materials used in this project included DNA extraction kit, PCR kit, the kit required to determine the product sequence of PCRs, NGS device and its accessories, sampler, microtube, and sampler tip.
3. Results 
In both patients, the disease-causing mutation was observed in the form of homozygote. One of the patients developed c.443G>A mutation in exon 4 of the GLB1 gene. Besides, the other patient generated c.313A>G mutation in exon 3 of the GALNS gene (Table 1).
4. Discussion 
One of the mutations had already been reported in other studies; however, the other mutation was first reported in this study. To obtain expand the achieved results and mutations data in relation to this genetic disease, it is necessary to investigated larger sample sizes. Accordingly, the number of unreported genetic mutations could be observed in the Iranian population. A study limitation was the lack of funding for conducting the genetic research.
5. Conclusion 
According to the literature on various types of mucopolysaccharidosis, we hope that the present study results be of great help in diagnosing prenatal disease of type 4 mucopolysaccharidosis. A new unreported mutation has been observed in this study for the first time; thus, it is suggested that a larger statistical population of Iranian patients with mucopolysaccharidosis be genetically studied. Such explorations could provide a more comprehensive report of pathogenic mutations in these patients. 

Ethical Considerations
Compliance with ethical guidelines
The present study has been approved by the Ethics Committee of Kowsar Human Genetics Research Center under the attached form No. 98/6299.
Funding
This study has been extracted from the PhD. thesis of Seyed Mehdi Shafaat in the field of Biology, Molecular Genetics, Islamic Azad University, Tehran North Branch. 
Authors' contributions
All authors contributed in designing, running, and writing all parts of the research.
Conflicts of interest
According to the authors, there is no conflicts of interest in this article.
Acknowledgements
We would like to thank all the colleagues of Kowsar Human Genetics Research Center who contributed to this research project.