[Analysis of a child with mucopolysaccharidoses type I due to compound heterozygous variants of IDUA gene].

OBJECTIVE

To analyze the clinical and genetic characteristics of a child with mucopolysaccharidoses type I.

METHODS

Enzymatic and genetic testing were carried out for the child who was admitted due to contraction of fingers and flexion deformity of lower limbs. The child was subjected to target exome capture sequencing. Candidate variants were verified by Sanger sequencing of the child, her parents and two sisters.

RESULTS

The child had featured facial dysmorphism, short stature, round head, short neck, corneal turbidity and skeletal deformity. Enzyme test was positive, and genetic testing revealed that she had harbored c.1049delA (p.N350Mfs*4) and c.1815dupT (p.V606Cfs*53) compound heterozygous variants of the IDUA gene, which were inherited from her mother and father, respectively. Her two sisters had each carried one of above variants. c.1815dupT was known to be pathogenic, whilst c.1049delA was not reported in Human Gene Mutation Database.

CONCLUSION

The compound heterozygous variants of the IDUA gene probably underlay the disease in this child, among which the c.1049delA (p.N350Mfs*4) is unreported previously.