DeSanctis–Cacchione syndrome or Xeroderma pigmentosum is a Genetic disorder characterized by the skin and eye symptoms of xeroderma pigmentosum (XP) occurring in association with microcephaly, progressive mental retardation, retarded growth and sexual development, deafness, choreoathetosis, ataxia and quadriparesis.
Genetics
In at least some case, the gene lesion involves a mutation in the CSB gene.It can be associated with ERCC6. [Source: Wikipedia 
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