A Rare Co-occurrence of Williams Syndrome and 𝘛𝘕𝘒2 Gene-Related Epilepsy

Williams syndrome is a multisystem disorder characterized by developmental delay, characteristic facial features, growth abnormalities, and cardiovascular abnormalities. The disorder is an autosomal dominant genetic syndrome that occurs due to microdeletion at chromosomal locus 7q11.23. Seizures occur uncommonly in association with Williams syndrome. Mutations in the <i>TNK2</i> gene have been found in rare cases of autosomal recessive infantile-onset epilepsy. We describe a rare co-occurrence of Williams syndrome and <i>TNK2</i> gene-related epilepsy in a child born of consanguineous parents. This case report emphasizes the role of genetic testing in the diagnosis of rare diseases. This is the fourth case report of epilepsy with biallelic mutations in the <i>TNK2</i> gene, to the best of the authors' knowledge.