| Answer to PhotoQuiz 31 |
| Mucopolysaccharidosis Type IV (OMIM # 253000 & 253010) |
| Mucopolysaccharidosis (MPS) type IV, also known as Morquio syndrome, is an autosomal recessive lysosomal storage disorder characterized by short stature, dysostosis multiplex, significant skeletal deformities, mild coarsening of facies and variable degree of corneal clouding and hepatospleno-megaly. Affected individuals have normal intelligence. MPS IVA is caused by homozygous or compound heterozygous mutations in the GALNS gene on chromosome 16q24, which result in deficient activity of the lysosomal enzyme galactosamine-6-sulfate sulfatase. MPS IVB is caused by homozygous or compound heterozygous mutations in the GLB1 gene on chromosome 3p22, which result in deficient activity of the beta-galactosidase enzyme. |
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| Correct responses were given by: |
| 1. Adhisivam B, Pondicherry |
| 2. Risha Nahar Lulla, Hyderabad |
| 3. Poonam Singh Gambhir, Lucknow |
| 4. Mohandas Nair, Kozhikode |
| 5. Diksha Shirodkar, Goa |
| 6. Gireesh S, Kozhikode |
| 7. Ravi Goyal, Kota, Rajasthan |
| 8. Namrata Das, Bhubaneshwar |