Identification of a novel mutation in the SGSH gene in an Indian child with Sanfilippo syndrome type IIIA

We describe an Indian child with Sanfilippo syndrome type IIIA with a novel mutation. The child is six years old, fifth in birth order, born of non-consanguineous marriage. The child presented with global developmental delay, autistic features, hyperactivity, wide smile, thick bushy eyebrows and umbilical hernia. The clinical exome analysis (next generation sequencing analysis of 8000 genes) identified homozygosity for Chr17:78187615:G>A or c.C733T or p.R245C mutation in the SGSH gene. This is a novel substitution at the common hotspot Arg245, where p.R245H has been the most commonly reported mutation worldwide. Bioinformatics analysis by Hope software revealed that the pathogenicity of this substitution could be due to disturbed interactions with other residues, such as aspartic acid 179 and glutamic acid 195. This is the second case report of Sanfilippo syndrome type IIIA from India with an associated genetic mutation.